1 00:00:01,970 --> 00:00:11,650 Hello. Thank you, moderator. This is Rafael Riva-Torres with Keysight Technologies, and I'm an R&D application scientist. 2 00:00:12,810 --> 00:00:20,870 Today, I want to talk to you guys about how to model, do some digital beamforming phase array, right? 3 00:00:21,089 --> 00:00:27,030 And let's talk about the concept also of phase array, about channel-specific impairment. 4 00:00:27,030 --> 00:00:30,829 So that's the overarching theme for today. 5 00:00:30,829 --> 00:00:43,090 Okay, now my agenda, we're going to cover some phased array trade study, phased array active loading and scaling, and a digital Rx phased array. 6 00:00:43,090 --> 00:01:04,189 Now, this presentation is born out of several interactions, both personal and customer. So the first one, this phase array trade study. You know, we do trade studies and this is actually some, born out of some personal experience. 7 00:01:04,189 --> 00:01:11,510 You're asked for a trade study, you're given a certain set of conditions, and this is one 8 00:01:11,510 --> 00:01:17,430 of those things that people just sometimes, you know, management, program managers, etc., 9 00:01:17,430 --> 00:01:24,290 think you can just turn this thing around or just sit down, you know, do a few calculations 10 00:01:24,290 --> 00:01:25,290 and you're done. 11 00:01:25,290 --> 00:01:28,730 It never results that way. 12 00:01:28,730 --> 00:01:35,170 So how can we use a tool like Pathway System Design to help us do our trade study, right? 13 00:01:35,230 --> 00:01:37,849 Again, some personal experience. 14 00:01:40,150 --> 00:01:45,750 I also want to talk about some new features that we put into our Pathway System Site 2022 15 00:01:45,750 --> 00:01:51,650 that I honestly believe will do two things for you. 16 00:01:51,650 --> 00:01:56,750 It increases the accuracy of your phased array simulations, 17 00:01:56,750 --> 00:02:01,829 and it also provides some relief in terms of simulation time. 18 00:02:02,430 --> 00:02:06,390 And the simulation time is not all in pathway system design. 19 00:02:06,629 --> 00:02:07,650 We'll look at that, right? 20 00:02:07,689 --> 00:02:10,050 Some of these EM simulations can be really long. 21 00:02:10,250 --> 00:02:10,990 How can we help? 22 00:02:12,009 --> 00:02:12,870 We'll see that. 23 00:02:13,050 --> 00:02:15,270 That's what this whole scaling thing is about. 24 00:02:15,889 --> 00:02:17,849 We'll talk some more about that when we get there. 25 00:02:17,849 --> 00:02:22,490 And the third topic, working with a customer and they come, 26 00:02:22,590 --> 00:02:26,430 oh, you guys have some nice solution for phased array analysis. 27 00:02:26,430 --> 00:02:30,409 But, you know, all phase arrays today are going digital, right? 28 00:02:30,509 --> 00:02:34,509 There's no such thing as, in the case of this customer, 29 00:02:34,729 --> 00:02:42,770 as a phase array where we can plug in, you know, an RF signal 30 00:02:42,770 --> 00:02:45,550 and, you know, do testing, et cetera. 31 00:02:45,729 --> 00:02:48,189 So we would like to actually design that way. 32 00:02:48,689 --> 00:02:50,750 Well, you know, we have a solution for you. 33 00:02:50,949 --> 00:02:52,569 So let's talk about that one, right? 34 00:02:52,710 --> 00:02:54,069 That's our last topic. 35 00:02:54,069 --> 00:02:56,289 Actually, the picture that you're seeing here on the top, 36 00:02:56,430 --> 00:02:59,949 is actually that phase array you can see there's an analog to digital converter 37 00:03:01,069 --> 00:03:06,189 that's going to be our digital output and we're actually going to do the beamforming in the digital 38 00:03:06,189 --> 00:03:14,270 domain it's so i'll leave the details for later so when we get there so let's move on to the trade 39 00:03:14,270 --> 00:03:24,560 study so here's the situation right i i changed some of the characteristics to sort of protect 40 00:03:24,560 --> 00:03:32,060 some of the names but again seriously some of the stuff that as engineers we 41 00:03:32,060 --> 00:03:35,840 live through right here's just your situation there's a phaser a team is 42 00:03:35,840 --> 00:03:41,419 working on some SATCOM program and they've been tasked with a trade study 43 00:03:41,419 --> 00:03:49,039 right you need to determine the cost and performance of the proposed ISA and 44 00:03:49,039 --> 00:03:52,120 and it's going to be used in the ground station uplink. 45 00:03:54,039 --> 00:03:55,340 And here's a proposed design. 46 00:03:55,439 --> 00:04:00,039 Here's somebody put it together for you in pathway system design. 47 00:04:00,139 --> 00:04:01,300 It kind of looks like this, right? 48 00:04:01,400 --> 00:04:02,580 And that's your design. 49 00:04:02,719 --> 00:04:05,080 Let's say that's the case, right? 50 00:04:05,939 --> 00:04:07,819 So what is the trace study all about? 51 00:04:08,300 --> 00:04:09,719 Well, here's the problem statement. 52 00:04:09,819 --> 00:04:12,719 We have the SACCOM ground station phase array. 53 00:04:12,719 --> 00:04:15,840 It has 625 antenna elements. 54 00:04:15,840 --> 00:04:22,420 we're looking for an EIRP of 400 kilowatts and somebody decided to put a 55 00:04:22,420 --> 00:04:26,759 tailor window on it and there's the characteristics of your tailor window now 56 00:04:26,759 --> 00:04:34,019 your trade study is there's two PAs available right and people cannot make 57 00:04:34,019 --> 00:04:40,199 up their mind right which one to use so your task for this trade study is select 58 00:04:40,199 --> 00:04:48,639 either one of the PAs, right, and cheapest is not always the best, nor is expensive always the best 59 00:04:48,639 --> 00:04:57,660 either, right, higher cost. Or you can actually do some kind of optimization and use a combination 60 00:04:57,660 --> 00:05:05,160 of the two. And how do we do that in the phase array analysis, right? How can you even accomplish 61 00:05:05,160 --> 00:05:11,779 we'll look at it. So we have two PAs, one of them is called PA1, and then we have PA2. 62 00:05:11,819 --> 00:05:17,540 You can see the characteristics for gain and frequency are very similar, and then you look 63 00:05:17,540 --> 00:05:23,959 at the output saturation power. There's one at 2 watts, and there's one at 20 watts, right? 64 00:05:24,019 --> 00:05:28,939 That's 10 watt difference, and there's like a 6x difference in price, and then a really 65 00:05:28,939 --> 00:05:36,079 large difference in terms of power, almost 15x or so. 66 00:05:36,079 --> 00:05:43,439 And by the way, we didn't magically pull these numbers, we actually did a quick survey around 67 00:05:43,439 --> 00:05:49,660 several vendors and we looked for vendors that had PAs that work in this frequency range 68 00:05:49,660 --> 00:05:57,480 and kind of what the difference in price and power was and this is what we came up with. 69 00:05:57,480 --> 00:06:02,579 of average of everything that we found so this is kind of reasonable to think 70 00:06:02,579 --> 00:06:12,240 that a 20 watt versus 2 watt PA would be like a six times the cost now you have 71 00:06:12,240 --> 00:06:16,500 to compare these two PAs and make and have even a third option where you 72 00:06:16,500 --> 00:06:22,800 optimize where you put one PA or the other in your array right 625 elements 73 00:06:22,800 --> 00:06:30,399 is a 25 by 25 array. Now you might be inclined to say oh I'm just built three 74 00:06:30,399 --> 00:06:37,319 three schematics and I will run three simulations I get you know three data 75 00:06:37,319 --> 00:06:43,300 sets and I can compare them all right but in pathway systems I you you do not 76 00:06:43,300 --> 00:06:52,360 have to do that you can create one schematic and then sorry about that you 77 00:06:52,360 --> 00:06:57,220 can then use certain properties that we have that we allow you to select 78 00:06:57,220 --> 00:07:04,959 different components programmatically so you see this small snippet of MATLAB 79 00:07:04,959 --> 00:07:09,160 code this is MATLAB code the one that's built into pathway system design no 80 00:07:09,160 --> 00:07:13,620 extra license needed it comes with the tool so I have this variable select 81 00:07:13,620 --> 00:07:17,560 notice assessor select one two three I have enough these components I have them 82 00:07:17,560 --> 00:07:21,759 such that when you select number one number one is active the other two are 83 00:07:21,759 --> 00:07:26,639 open number two the middle one is active the other two are open and so on right the same thing with 84 00:07:26,639 --> 00:07:35,480 the third one um and this just makes life easier right what you have is one single schematic you 85 00:07:35,480 --> 00:07:40,899 just go to this script you tell it to run and it actually does that right it says okay this time 86 00:07:40,899 --> 00:07:47,519 i'm going to use a data set for the 33 dbmpa it runs the analysis then for the 43 and then there's 87 00:07:47,519 --> 00:07:53,899 this thing called a group PA. What's this group PA thing all about, right? Well, I'll 88 00:07:53,899 --> 00:07:58,439 talk about that in a second. So the whole idea is you have a swift analysis, single 89 00:07:58,439 --> 00:08:05,120 schematic, you know, be working with three schematics. You make a change in one, you 90 00:08:05,120 --> 00:08:10,740 have to go to the other to make the same change, and all this stuff, you avoid all that. So 91 00:08:10,740 --> 00:08:16,139 this PA is something new that we came out in our last release it's called an 92 00:08:16,139 --> 00:08:22,360 array RF amp and it's an array of amplifiers that's two things for you 93 00:08:22,360 --> 00:08:31,740 right number one it allows you to have all the amplifiers with different values 94 00:08:31,740 --> 00:08:36,460 when you run your Monte Carlo analyses right so in the past we were you the RF 95 00:08:36,460 --> 00:08:42,399 amp and sure you can run in a Monte Carlo analysis but all 625 would have 96 00:08:42,399 --> 00:08:51,200 the same gain and same 1 DB compression point etc because it was just one 97 00:08:51,200 --> 00:08:56,740 component right this one actually you have 625 amp the flyers in this 98 00:08:56,740 --> 00:09:02,500 component which is the way our face array solution works and each one when 99 00:09:02,500 --> 00:09:07,200 you run the Monte Carlo will have, you know, whatever within the statistical variations that 100 00:09:07,200 --> 00:09:12,940 you specify will be different. So that's one use case. The other advantage of this is you can create 101 00:09:12,940 --> 00:09:18,740 groups of PAs, right? Remember one of the options, one of the three options for your trace study, 102 00:09:18,740 --> 00:09:25,720 you can use a combination. What that means is some of your elements can be fed by PA1 and 103 00:09:25,720 --> 00:09:32,340 some other group of your element, antenna elements, can be fed by PA2. So that is a third option. 104 00:09:32,500 --> 00:09:41,080 right so we did that we did this analysis and let's look first at let's 105 00:09:41,080 --> 00:09:45,940 say PA 1 and PA 2 so PA 2 is a yellow one and I'm gonna be consistent with my 106 00:09:45,940 --> 00:09:53,120 colors and PA 1 is a blue one and the figure of merit that we're gonna look at 107 00:09:53,120 --> 00:09:58,500 today is gonna be C and DR which stands for character noise and distortion ratio 108 00:09:58,500 --> 00:10:06,500 like your signal to noise ratio but including distortion and the 109 00:10:06,500 --> 00:10:12,000 dots that you see here there's 625 of them so it represents each channel in 110 00:10:12,000 --> 00:10:19,259 your phasor right so there's 625 elements so there's 625 channels and you 111 00:10:19,259 --> 00:10:24,460 can see that the blue one right by the way CMDR is one of those parameters that 112 00:10:24,460 --> 00:10:29,980 the higher the better and you'll notice that the yellow which is the more 113 00:10:29,980 --> 00:10:36,460 expensive higher power one has a much better on average CMDR if you want to 114 00:10:36,460 --> 00:10:42,200 think of it that way whereas the blue one you know it has some some challenges 115 00:10:42,200 --> 00:10:47,580 right it kind of dips below 20 this line here is 20 might be a little bit hard to 116 00:10:47,580 --> 00:10:52,000 see but my scale here alright so it drops almost all the way down to you 117 00:10:52,000 --> 00:10:59,059 went to 15. So that's not a good thing, right? Definitely you can see where using all PA1s is 118 00:10:59,059 --> 00:11:04,039 not as good as using all yellow ones, but all the yellow ones, which is PA2, they're more expensive, 119 00:11:04,039 --> 00:11:13,559 more DC power. So what if we could do something where we say, replace all the PA1s with PA2s 120 00:11:13,559 --> 00:11:24,379 where and only if CMDR drops below 30 for PA1. If it stays above 30, and here's our 30 line, 121 00:11:24,379 --> 00:11:29,740 right, which is quite a few of them, we're going to leave it alone and we'll only replace it when 122 00:11:29,740 --> 00:11:39,840 it falls below 30, right? So we sort of did that. And so here's where we're going to use group PA, 123 00:11:39,840 --> 00:11:46,000 we're going to use both of them again the color scheme holds right blue dots are pa1 and yellow 124 00:11:46,000 --> 00:11:55,440 dots are pa2 notice that when you replace them everything says above 30. all right and um well 125 00:11:55,440 --> 00:12:00,879 how good is that right and let's be able to come we should be able to compare all three solutions 126 00:12:00,879 --> 00:12:05,840 now that's what our trade study that's the outcome or the desired outcome of our trade study 127 00:12:05,840 --> 00:12:15,759 so I'm going to use the traffic light indicators here for what's good right red means not good 128 00:12:15,759 --> 00:12:24,379 yellow means somewhere in the middle and green means the best right sorry so here's PA all PA 129 00:12:24,379 --> 00:12:31,179 ones ERP does not have a color it's not highlighted because all options meet the EIRP 130 00:12:31,179 --> 00:12:37,980 Notice that even with PA1, right, the problem with PA1 is it has the lowest CMDR RMS. 131 00:12:38,080 --> 00:12:45,860 So we did an RMS across all 625 channels, and we came up with 34.7, right? 132 00:12:46,620 --> 00:12:51,460 What it has going for it, it's the lowest cost and the lowest power consumption. 133 00:12:54,059 --> 00:12:55,960 Now, here's the version with PA2. 134 00:12:56,080 --> 00:12:58,059 Again, EIRP is not a factor here. 135 00:12:58,059 --> 00:13:02,419 It also meets the requirements handsomely now, right? 136 00:13:02,940 --> 00:13:12,179 Notice the CMDR RMS went up to 39, pretty good, where it's not so good as in cost and DC power, right? 137 00:13:12,659 --> 00:13:22,039 We know that the overall cost here is six times more than with PA1, which, you know, the program is not enjoying right now. 138 00:13:22,820 --> 00:13:25,419 All right, so here's the version with the group PAs. 139 00:13:25,419 --> 00:13:31,519 Remember, we replaced the blue ones with yellow only when the CMDR dropped below 30. 140 00:13:31,519 --> 00:13:36,019 and notice that I have the parameters here all yellow by the way notice that 141 00:13:36,019 --> 00:13:42,440 yeah he we only drop 0.1 DB compared to the all PA twos we're just kind of 142 00:13:42,440 --> 00:13:49,460 fantastic and fabulous result by the way cndr did drop a little bit but still 143 00:13:49,460 --> 00:13:54,379 it's better than just all PA ones and you can kind of judge for yourself in 144 00:13:54,379 --> 00:14:05,179 terms of power and cost right and this is a visual from pathway system design 145 00:14:05,179 --> 00:14:11,360 it is actually our new phase array visualizer that does this right so you 146 00:14:11,360 --> 00:14:15,320 can actually tell it oh yeah I want the colors for this this or that parameter 147 00:14:15,320 --> 00:14:18,940 it numbers and it does a few things that helps you visualize your phase array 148 00:14:18,940 --> 00:14:26,320 right so by the way we're using CMDR because it is inversely proportional to 149 00:14:26,320 --> 00:14:30,379 EVM so if you're doing any kind of digital comms and things like that you 150 00:14:30,379 --> 00:14:35,320 know that here's where the higher the CMDR the better for yourself for you 151 00:14:35,320 --> 00:14:41,740 right and we end up with the conclusion that amplifier grouping is the best 152 00:14:41,740 --> 00:14:47,139 compromise in terms of performance and cost now of course if it happens to you 153 00:14:47,139 --> 00:14:53,379 like it happens to me when i do these trade studies uh your boss says um can we lower the 154 00:14:53,379 --> 00:15:00,340 the cost some more and still kind of meet the requirements of course the answer is oh i just 155 00:15:00,340 --> 00:15:07,299 need to rerun the trade study and what do you want me to change the lowest uh cndr for right so we 156 00:15:07,299 --> 00:15:12,500 did it at 30 you you know what if you want to experiment let's say with 28. you can go back 157 00:15:12,500 --> 00:15:18,500 and do that and do these trade studies and all these what-ifs right and you the most fabulous 158 00:15:18,500 --> 00:15:28,419 thing is this analysis uh took me like uh from scratch setting it up um running the simulations 159 00:15:28,419 --> 00:15:34,340 and even putting the slides together it takes like four hours um and to be honest with you 160 00:15:34,340 --> 00:15:42,340 the simulations are incredibly fast the whole three simulations that was like somewhere around 161 00:15:42,340 --> 00:15:49,700 12 seconds is where we clock that at which again on my computer so it's pretty fast uh accurate 162 00:15:49,700 --> 00:15:54,820 and um it doesn't really take that much to set up and by the way once you have it set up guess what 163 00:15:54,820 --> 00:15:59,379 you can do all these what ifs that your boss is gonna or the program is gonna ask you anyway 164 00:16:02,379 --> 00:16:10,460 okay so let's talk about a couple of really nice features honestly uh for our phased array solution 165 00:16:10,460 --> 00:16:17,179 which is active loading and scaling and they actually go together somewhat but let's talk 166 00:16:17,179 --> 00:16:26,039 about what we mean by active loading so in the antenna array pair uh panel excuse me an antenna 167 00:16:26,039 --> 00:16:31,940 array panel active loading is a result of em coupling between the 10 array elements so there's 168 00:16:31,940 --> 00:16:36,600 all kinds of coupling between those array elements i'm showing four of them here you can see already 169 00:16:36,600 --> 00:16:40,720 with four of them, how much coupling you have. 170 00:16:40,720 --> 00:16:44,580 This coupling will depend on how close, the proximity between the elements, the farther 171 00:16:44,580 --> 00:16:46,759 away the less coupling, right? 172 00:16:46,759 --> 00:16:51,799 And there's other design things that you can do to try to reduce the coupling between them. 173 00:16:51,799 --> 00:16:54,539 We can capture this coupling with S-parameters. 174 00:16:54,539 --> 00:17:01,840 So if you're running an EM analysis, pick your favorite 3D EM analysis, either ours 175 00:17:01,840 --> 00:17:08,140 or the competition we support several of our competitors a CST HFSS you can 176 00:17:08,140 --> 00:17:17,079 bring in those files into our tool and if captured a copy matrix you know the 177 00:17:17,079 --> 00:17:21,460 couple signal levels is what sometimes people mess right so what I mean by that 178 00:17:21,460 --> 00:17:27,799 is how much of this signal and port two couples back to port one and from port 179 00:17:27,799 --> 00:17:33,700 3 to port 1 and so on and so forth right so how much how much is that so it 180 00:17:33,700 --> 00:17:39,019 doesn't only depend on the coupling matrix it also depends on the actual 181 00:17:39,019 --> 00:17:44,299 value of the signal remember in the prior trade study we had a Taylor window 182 00:17:44,299 --> 00:17:47,980 so that means that the amplitude that goes into the end each other antennas it 183 00:17:47,980 --> 00:17:56,180 conceivably different right the other thing is this excitation voltage yes 184 00:17:56,180 --> 00:18:02,119 will change with your scan angle so as you're scanning also these voltages 185 00:18:02,119 --> 00:18:07,819 these are all the effects that you need to capture right and again you bring in 186 00:18:07,819 --> 00:18:11,900 the antenna patterns you bring up in your coupling matrix and our tool will 187 00:18:11,900 --> 00:18:16,640 consume that and allow you to do that analysis now let's talk about this 188 00:18:16,640 --> 00:18:23,960 coupling matrix and antenna patterns and let's say that we want to do a large 189 00:18:23,960 --> 00:18:28,819 array but in my case here I'm gonna say that a large array is a 10 by 10 array 190 00:18:28,819 --> 00:18:34,460 which depending on your EM simulator what you set up the frequency and all 191 00:18:34,460 --> 00:18:40,480 kinds of other things that can be a fairly long simulation right but it gets 192 00:18:40,480 --> 00:18:45,259 to a point with your race starts to grow even further than this there's things 193 00:18:45,259 --> 00:18:49,940 and the different EM tools that help you speed up things you can do like an 194 00:18:49,940 --> 00:18:55,759 infinite array etc etc all these kind of things and that's not really nice and 195 00:18:55,759 --> 00:19:00,660 good but you know when you have to come back and do an array like the analysis 196 00:19:00,660 --> 00:19:05,779 like we do it in pathway system design that also means you have to bring all 197 00:19:05,779 --> 00:19:11,319 that data right not only did you have to wait for the data sometimes even days 198 00:19:11,319 --> 00:19:18,660 right you also have to just transfer all that data now we came up this is a 199 00:19:18,660 --> 00:19:25,140 innovation from us in pathway system design and we can actually scale small 200 00:19:25,140 --> 00:19:30,339 matrix to a big array right so our case here let's say we have a five by five 201 00:19:30,339 --> 00:19:38,579 and we can scale it up to a ten by ten or even bigger and what is the what is 202 00:19:38,579 --> 00:19:43,380 the the phenomenon how is it that we can do that well if you look at a phased 203 00:19:43,380 --> 00:19:48,420 array and you consider any element as soon as you get to two elements away 204 00:19:48,420 --> 00:19:51,480 from it by the time you get to the third one the coupling from that one back to 205 00:19:51,480 --> 00:19:55,500 your original one let's say I'm looking at 28 here right by the time I get to 206 00:19:55,500 --> 00:20:03,720 58 58 is going to show you a lot less than 38 and 48 right so we can say that 207 00:20:03,720 --> 00:20:12,299 I can approximate 28 and coupling to its neighbors with the next two elements 208 00:20:12,299 --> 00:20:17,779 right and then if you look at the bigger array that means that a lot of these 209 00:20:17,779 --> 00:20:23,579 antenna elements in terms of the coupling from their neighbors look very 210 00:20:23,579 --> 00:20:29,339 similar so for example 28 looks a lot like 38 why because 28 has two elements 211 00:20:29,339 --> 00:20:34,440 to the to the left to the right up and down and you can see even a diagonally 212 00:20:34,440 --> 00:20:40,200 it looks that's very similar to the position so what we end up doing when we 213 00:20:40,200 --> 00:20:45,579 scale is we say that everything with a similar color here they have a coupling 214 00:20:45,579 --> 00:20:54,000 babies they all have similar coupling to their neighbors right and the same thing 215 00:20:54,000 --> 00:20:58,980 with all the different colors what that means is if I can come up with a smaller 216 00:20:58,980 --> 00:21:05,099 matrix right that does that that captures that effect I have I only have 217 00:21:05,099 --> 00:21:10,440 to run an EM analysis of the smaller array, which 218 00:21:10,440 --> 00:21:16,700 saves incredible amounts of time and simulation in your EM tool. 219 00:21:16,700 --> 00:21:18,660 And remember that thing about transferring data? 220 00:21:18,660 --> 00:21:21,500 Data files are much smaller, right? 221 00:21:21,500 --> 00:21:23,319 So this is the concept, right? 222 00:21:23,319 --> 00:21:24,720 So we save you time. 223 00:21:24,720 --> 00:21:28,920 Not exactly all the time is saved in the pathway system design. 224 00:21:28,920 --> 00:21:32,539 It's actually saving you time and running your EM analysis. 225 00:21:32,539 --> 00:21:39,339 shorter em simulation and measurement time okay and you can run as big of an array as you want 226 00:21:39,339 --> 00:21:45,420 right i did a 10 by 10 here because in order to kind of prove to you guys that this kind of this 227 00:21:45,420 --> 00:21:51,660 this works i am going to do two things right i actually we actually did run the 10 by 10 array 228 00:21:51,660 --> 00:21:57,180 in in our em solver em pro from keysight technologies and we did run the five by 229 00:21:57,180 --> 00:22:07,170 five and i'm going to compare them side by side all right in typical fashion i like to run these 230 00:22:07,170 --> 00:22:13,809 scripts right i have three options so why not uh single schematic three options and i have my 231 00:22:13,809 --> 00:22:20,930 script again that sort of controls my simulation single schematic i can do everything now we have 232 00:22:20,930 --> 00:22:26,769 three cases the first one is no active impedance so we just put it together and we just we close 233 00:22:26,769 --> 00:22:33,890 our eyes and said there's no active impedance right there's a case and that 234 00:22:33,890 --> 00:22:42,890 we consider the less accurate it it works it gives you results and there's a 235 00:22:42,890 --> 00:22:47,529 lot of good things about it but there is the missing piece which is this active 236 00:22:47,529 --> 00:22:52,029 impedance right then there's the full active impedance that's the one where we 237 00:22:52,029 --> 00:22:58,190 ran the full EM for the 10x10 array and then there's the scaled one which is the one where 238 00:22:58,190 --> 00:23:04,589 we ran the 5x5 and then that's the data that we consumed inside of pathway system design 239 00:23:05,150 --> 00:23:10,670 and for directivity right and remember the active z is the most accurate we were getting 25 240 00:23:10,670 --> 00:23:17,630 and it seems that all three versions get pretty close right now look at the EIRP right 241 00:23:17,630 --> 00:23:22,750 So, the no active C gives you 53.1 dBm. 242 00:23:23,390 --> 00:23:28,190 The most accurate that we have is the active C, that's a by 10, 51.8. 243 00:23:28,829 --> 00:23:30,990 Kind of the difference with the no active, right? 244 00:23:31,509 --> 00:23:32,670 And notice the scale. 245 00:23:32,829 --> 00:23:37,190 The scale gives you 51.7, very, very close to the active C. 246 00:23:37,769 --> 00:23:40,589 So, while still an approximation, right? 247 00:23:41,109 --> 00:23:45,569 But it gives you really good results, fairly accurate, right? 248 00:23:45,569 --> 00:23:51,569 but then you save tremendous amount of time and resources transfer again data 249 00:23:51,569 --> 00:23:59,369 files and that sort of thing here's a few patterns for you to look at on the 250 00:23:59,369 --> 00:24:03,390 left is the sex in case that we were just looking the prior slide so not the 251 00:24:03,390 --> 00:24:11,490 scan angle of zero and you can look at the pattern and you can see for example 252 00:24:11,490 --> 00:24:15,930 the no active impedance have the really deep nulls but that doesn't really 253 00:24:15,930 --> 00:24:23,009 happen in the other array in the actual active C array and you can see that the 254 00:24:23,009 --> 00:24:29,730 scale one also does not have the really super deep nulls right in in the 255 00:24:29,730 --> 00:24:33,809 side the beam width and the main beam all three solutions looks very similar 256 00:24:33,809 --> 00:24:41,069 right and again we feel that the scale and the active C are closer than the no 257 00:24:41,069 --> 00:24:45,950 active and the same thing happens when you scan again inside the main beam 258 00:24:45,950 --> 00:24:52,589 there you begin to see some differences right again we feel that our scale 259 00:24:52,589 --> 00:24:58,589 solution is very good and again those deep notches that happen with the ideal 260 00:24:58,589 --> 00:25:03,329 one which don't happen with the other two right you will notice that farther 261 00:25:03,329 --> 00:25:10,829 away you get from the main beam in both cases the other two solutions do 262 00:25:10,829 --> 00:25:17,970 begin to depart from the active see the full-blown analysis if that were ever 263 00:25:17,970 --> 00:25:25,069 important to you you know consider still using the full array right but if you 264 00:25:25,069 --> 00:25:29,730 want to focus on the main beam and several side lobes near the main beam 265 00:25:29,730 --> 00:25:38,900 this is an you know the scale array is a fantastic option all right so we talked 266 00:25:38,900 --> 00:25:44,240 about some advantages that we give you and let's talk about the now about this 267 00:25:44,240 --> 00:25:50,299 phased array digital design right and we're going to do the RX again this is a 268 00:25:50,299 --> 00:25:56,240 customer is they want we all our phased arrays are moving to digital how can we do 269 00:25:56,240 --> 00:26:01,640 that but they still need to do some RF lineup right and understand some Monte 270 00:26:01,640 --> 00:26:05,240 Carlo some variability statistical analysis this is all stuff that we will 271 00:26:05,240 --> 00:26:16,750 do with pathway system design so part of the the situation here is some of the 272 00:26:16,750 --> 00:26:22,630 control is and some of these are the you know phase arrays do some of these 273 00:26:22,630 --> 00:26:28,809 being former ICS many of them are complete receivers right they have gain 274 00:26:28,809 --> 00:26:36,549 control they have even program of both filters they have integrated analog to 275 00:26:36,549 --> 00:26:40,630 digital converters etc so let's say you have one that looks like this and then 276 00:26:40,630 --> 00:26:44,230 you have many many of these because you have probably have one per channel some 277 00:26:44,230 --> 00:26:50,309 just bring two of them inside four of them inside sort of help reduce the chip 278 00:26:50,309 --> 00:26:55,329 count but still you have many of them right which is the point and how do you 279 00:26:55,329 --> 00:27:03,190 begin to your model this right then include it in your design I went ahead 280 00:27:03,190 --> 00:27:10,009 and make some assumptions totally convenient for this demo right hopefully 281 00:27:10,009 --> 00:27:18,150 some of you can relate to to the nature of it so in yellow is our beamformer IC 282 00:27:18,150 --> 00:27:23,509 so notice I have the mixer with the yellow I have I have some filter and I 283 00:27:23,509 --> 00:27:26,410 have a digital step attenuator to help with that level control or to gain 284 00:27:26,410 --> 00:27:39,829 control um now i wanted to do a minus 60 that i have an input signal um uh after the antenna panel 285 00:27:39,829 --> 00:27:47,109 right uh right at the input of my lna uh anywhere from minus 60 to minus 100 so i need a 40 db 286 00:27:47,109 --> 00:27:53,029 dynamic range a little bit of this is made up but kind of in that range let's say that this is 287 00:27:53,029 --> 00:27:59,349 uh kind of what you would expect out of uh the antenna elements in your array anywhere between 288 00:27:59,349 --> 00:28:05,670 in that range um now the thing about it is you have to be able to be in that range and at the 289 00:28:05,670 --> 00:28:11,029 output of this digital rxic right the only thing that's missing here by the way is the analog to 290 00:28:11,029 --> 00:28:17,109 digital converter so i don't know the digital converter let's say it has to say about 10 dvm 291 00:28:17,109 --> 00:28:23,029 of input power which is about it's one volt and if we assume 50 ohms it's one volt and whatever 292 00:28:23,029 --> 00:28:28,710 right whatever it is that you need let's say you wanted to have the right power level okay 293 00:28:29,269 --> 00:28:36,390 now i did a quick some analyses um and things like that and i figured out uh that i needed some more 294 00:28:36,390 --> 00:28:44,309 games so i brought in this vga mimic it also has some game control um and uh i ran a few analyses 295 00:28:44,309 --> 00:28:51,269 and I said, okay, at minus 60, this is what I have to set the two DCAs, 296 00:28:51,890 --> 00:28:54,769 and at minus 100, this is what I need to set the two DCAs. 297 00:28:55,329 --> 00:28:57,809 And in fact, in this workspace, if you guys get it, 298 00:28:58,049 --> 00:29:01,009 you'll notice that I have an equation that I can figure out any value 299 00:29:01,009 --> 00:29:03,569 for the DCAs between minus 60 and minus 100. 300 00:29:04,809 --> 00:29:08,329 For this demo, I'm going to stick to minus 60 and minus 100 levels, right, 301 00:29:08,390 --> 00:29:10,029 to not complicate things too much. 302 00:29:10,029 --> 00:29:17,210 but you know you can go to any value in between right and even outside of here it's just that 303 00:29:17,210 --> 00:29:23,650 my equations when I set up the workspace you'll notice that hey if you try to go below minus 100 304 00:29:23,650 --> 00:29:29,230 it fixes the DC at 4 and 1 for example and the same thing if you try to go above minus 60 305 00:29:29,230 --> 00:29:37,750 it'll fix the DCA values. Now the first thing that I did is I said oh I have let's say a 1 306 00:29:37,750 --> 00:29:42,869 megahertz wide signal and we're going to run it through our spectra says our RF 307 00:29:42,869 --> 00:29:49,269 analysis tool on the left it's a the lower spot lower power minus 100 dbm 308 00:29:49,269 --> 00:29:53,470 input power and we're looking at the output and you can see I'm about 10 dbm 309 00:29:53,470 --> 00:29:58,329 pretty close feel pretty good about it you'll notice that the noise level seems 310 00:29:58,329 --> 00:30:03,670 kind of high come back to that in a minute and then and the minus 60 again I 311 00:30:03,670 --> 00:30:06,809 got really close to the 10 dBm that I was looking for 312 00:30:07,809 --> 00:30:16,109 Then the noise level was a lot lower. Why is that? Well, we started off with a higher input power, right? 313 00:30:16,349 --> 00:30:17,910 so 314 00:30:17,910 --> 00:30:23,549 The higher input power means I don't need that much gain. So I have lower gain 315 00:30:24,289 --> 00:30:26,730 Remember I started with higher single level 316 00:30:26,730 --> 00:30:33,349 So, going through the circuit, the noise does not see the same amount of gain as it does 317 00:30:33,349 --> 00:30:36,049 when the signal power level is less. 318 00:30:36,049 --> 00:30:42,710 So that's why the signal power, when you have minus 100, the noise power is that much higher. 319 00:30:42,710 --> 00:30:44,549 You have much more gain here. 320 00:30:44,549 --> 00:30:49,140 Now prove that in the next slide. 321 00:30:49,140 --> 00:30:54,519 Here is the line up, or cascaded analysis of our receiver. 322 00:30:54,519 --> 00:31:02,200 notice, right, the minus 100, you definitely had to give it more gain in order to get to 323 00:31:02,200 --> 00:31:06,460 that output power level, and the output power level here is the green line, right, so we're 324 00:31:06,460 --> 00:31:11,579 trying to get to 10, here's the 10, right, so you need a lot more gain to do that. 325 00:31:12,500 --> 00:31:18,019 Other things on here is the cascaded noise power, those are the sort of purple lines, 326 00:31:18,099 --> 00:31:22,839 and then these teal lines, that is the carrier to noise and distortion ratio that we talked 327 00:31:22,839 --> 00:31:33,740 about earlier. I just like to plot those. We are convinced that unavoidably people like to see data 328 00:31:33,740 --> 00:31:39,339 also in table format. We provide table formats and things like that. You can see here, I always like 329 00:31:39,339 --> 00:31:45,680 to look at the center frequency, desired channel power, cascaded noise figures, character noise 330 00:31:45,680 --> 00:31:52,759 ratio, and this TIMP stands for total inner mod power. It gives you an idea of where your inner 331 00:31:52,759 --> 00:31:56,359 mods are being created, which is kind of a nice result. 332 00:31:56,359 --> 00:31:59,420 I'll focus, won't spend too much time here. 333 00:31:59,420 --> 00:32:03,140 Notice that the output power, again, somewhere close to 9 dBm, 334 00:32:03,140 --> 00:32:06,720 actually more, closer to 9 dBm than there, to 10. 335 00:32:06,720 --> 00:32:09,140 But this is the nominal value. 336 00:32:09,140 --> 00:32:11,759 What happens when things start to vary? 337 00:32:11,759 --> 00:32:14,200 We will look at that coming soon here. 338 00:32:17,700 --> 00:32:19,779 Of course, this is a phased array. 339 00:32:19,779 --> 00:32:22,259 And now we have phased array analysis, right? 340 00:32:22,259 --> 00:32:26,759 We want a phased array, so why don't we go ahead and convert our schematic to phased array. 341 00:32:27,039 --> 00:32:30,420 So I'm using the famous array RF amplifiers. 342 00:32:30,539 --> 00:32:34,019 I replaced all my amplifiers by those, right, just to be able to do that. 343 00:32:34,099 --> 00:32:39,359 Remember, I told you there was an advantage when you do Monte Carlo analysis using those, right? 344 00:32:39,400 --> 00:32:43,779 And that's that the whole bank of all the amplifiers will be different, 345 00:32:43,779 --> 00:32:48,920 will have slightly different values when you run your Monte Carlo, which is a huge advantage here, right? 346 00:32:48,920 --> 00:32:52,200 and let's just for argument's sake say that that's where most of our 347 00:32:52,200 --> 00:32:55,799 variability is going to come from right let's say you know that this is a 348 00:32:55,799 --> 00:32:58,759 really good analysis a good way to do that 349 00:32:58,759 --> 00:33:01,720 of course because we do phase array we can always show you the the antenna 350 00:33:01,720 --> 00:33:07,180 pattern this antenna pattern for the nominal case 351 00:33:07,180 --> 00:33:10,859 all right so here's the the Monte Carlo analysis 352 00:33:10,859 --> 00:33:13,980 so on the left that's the desired channel power 353 00:33:13,980 --> 00:33:17,579 remember i'm trying to get the same power no no uh output 354 00:33:17,579 --> 00:33:25,200 no matter what the input power is between minus 60 and between 100 and 6 minus 60 right so notice 355 00:33:25,200 --> 00:33:30,279 that the blue is for the higher power and the green is for the lower power and you can see that 356 00:33:30,279 --> 00:33:36,400 the statistics looks very close which is a desired result here by the way right because we were aiming 357 00:33:36,400 --> 00:33:43,500 for that remember that our average was our nominal was looking around nine or so you can see that 358 00:33:43,500 --> 00:33:48,460 over the variations, at least the ones that I'm using here, 359 00:33:48,460 --> 00:33:50,099 you can see some of them actually 360 00:33:50,099 --> 00:33:53,339 go above 10, which is probably something you don't want, 361 00:33:53,339 --> 00:33:54,299 right? 362 00:33:54,299 --> 00:33:58,740 Probably driving your analog to the other converter 363 00:33:58,740 --> 00:34:00,740 a little too hard. 364 00:34:00,740 --> 00:34:02,819 And then on the lower side, maybe the signal 365 00:34:02,819 --> 00:34:04,440 level's getting a little too low, right? 366 00:34:04,440 --> 00:34:09,219 Maybe this is something you have to address, OK? 367 00:34:09,219 --> 00:34:12,599 I didn't want to look at output P1 dB, 368 00:34:12,599 --> 00:34:20,699 Because this is a receiver, most people are more interested in the 1 PD1 input, PD1 dB, or 1 dB compression point. 369 00:34:21,159 --> 00:34:26,219 Notice that the lower power has a lower one, and the higher power has a higher P1 dB. 370 00:34:26,219 --> 00:34:29,619 Again, that's due to the difference in gain between the two. 371 00:34:30,280 --> 00:34:33,079 And the difference in gain between the two is about 30 dB. 372 00:34:33,539 --> 00:34:37,400 So that's the difference that you see in this plot, about that difference. 373 00:34:37,400 --> 00:34:47,210 right um let me throw in another plug for my pathway system design we used to not be able 374 00:34:47,210 --> 00:34:52,650 to do two-tone analysis and our receive phase right we've been always able to do that and 375 00:34:52,650 --> 00:35:00,409 transmit um and we did add the the capabilities to do that in this last release so now you can 376 00:35:00,409 --> 00:35:06,809 do two tones see and receive two tones it's kind of an interesting thing because are the two tones 377 00:35:06,809 --> 00:35:10,570 coming from the same direction or they come from different directions and things like that we 378 00:35:10,570 --> 00:35:15,690 actually solve that problem uh so if you put them in the same direction with the two-tone analysis 379 00:35:15,690 --> 00:35:20,570 you can put them coming from different directions even from different they can be different obviously 380 00:35:20,570 --> 00:35:28,250 different frequencies close not so close in general it's a very nice general jet in general 381 00:35:28,250 --> 00:35:32,650 uh two-tone analysis and you can do multi-tones right we actually support multi-tones 382 00:35:32,650 --> 00:35:39,230 As you can see here, kind of the different groups, I'm going to zoom into the fundamental 383 00:35:39,230 --> 00:35:44,230 areas in a second here, but you can see you can track the different harmonics and again 384 00:35:44,230 --> 00:35:56,800 going for that equal output power between the two. 385 00:35:56,800 --> 00:36:02,659 So here are the two-tones analysis when we run this. 386 00:36:02,659 --> 00:36:10,199 Notice that when you have the higher output power, 387 00:36:10,199 --> 00:36:14,639 it's definitely you have a lower IP3 than with a lower power. 388 00:36:14,639 --> 00:36:21,139 And again, all this goes back to the input, 389 00:36:21,139 --> 00:36:24,980 the gain of the two blocks, the two options, 390 00:36:24,980 --> 00:36:37,900 you have lower power and higher power okay all right so let's say you're happy with your rf uh 391 00:36:38,860 --> 00:36:48,539 design and uh you're getting ready to now uh do some waveform analysis and actually put some uh 392 00:36:49,099 --> 00:36:56,780 digital beamforming right so our block here is uh our phase array all the electronics rf 393 00:36:56,780 --> 00:36:59,079 that we've just been looking at. 394 00:36:59,079 --> 00:37:02,579 That's this block, which we do through RFLink. 395 00:37:02,579 --> 00:37:06,659 So RFLink is our way of actually incorporating 396 00:37:06,659 --> 00:37:09,099 from the RF domain analysis that we were doing 397 00:37:09,099 --> 00:37:14,099 into our digital or time domain analysis that we can do. 398 00:37:14,940 --> 00:37:16,179 Notice that I actually have 399 00:37:16,179 --> 00:37:18,639 a fully framed digital source here. 400 00:37:18,639 --> 00:37:21,539 I've shown these before in other presentations 401 00:37:21,539 --> 00:37:23,539 and if you want more information, 402 00:37:23,539 --> 00:37:28,480 Please see the documentation, or I'll talk about some references 403 00:37:28,480 --> 00:37:33,000 in a little bit about where you can get more information. 404 00:37:33,000 --> 00:37:35,400 Notice that I have the same slider for the power. 405 00:37:35,400 --> 00:37:38,179 And again, we can do it minus 100 and minus 60, 406 00:37:38,179 --> 00:37:43,500 which I'll do in the following slides. 407 00:37:43,500 --> 00:37:45,420 This block represents an antenna manifold. 408 00:37:45,420 --> 00:37:47,880 Remember, we had an antenna manifold in the phase array analysis. 409 00:37:47,880 --> 00:37:48,860 We also have one here. 410 00:37:48,860 --> 00:37:51,239 This is the block. 411 00:37:51,239 --> 00:37:53,380 And then we added the analog to digital converter 412 00:37:53,380 --> 00:37:56,980 that was missing from our in the RF domain right we don't really have an 413 00:37:56,980 --> 00:38:01,619 analog to digital converter in the RF domain that's a digital time domain 414 00:38:01,619 --> 00:38:08,500 component I have a very basic built-in beamformer I'm showing you the details 415 00:38:08,500 --> 00:38:14,920 down here the actual case and we've seen this a couple of times you know 416 00:38:14,920 --> 00:38:22,199 customers want to come and use their own digital or baseband beamformer you're 417 00:38:22,199 --> 00:38:27,179 more than welcome to do that there's several ways to do that but in this case 418 00:38:27,179 --> 00:38:31,500 I'm gonna use our built-in one which is kind of nice and convenient to do here 419 00:38:31,500 --> 00:38:35,760 and just kind of the way we will set it up I didn't do any scan angles I was 420 00:38:35,760 --> 00:38:41,579 gonna do that but sort of you know have to limit in time so I left everything 421 00:38:41,579 --> 00:38:46,739 as zero so no scanning we're not gonna do any scanning here this game block is 422 00:38:46,739 --> 00:38:51,420 only to scale back down because I want to use the VSA software to demodulate my 423 00:38:51,420 --> 00:38:56,099 signal so what happens is in the analog to geoconverter being a true analog to 424 00:38:56,099 --> 00:39:03,179 digital converter right it's 12 bits so that output center goes between 0 and 2 425 00:39:03,179 --> 00:39:11,219 to the 12 that's a really nice number so I I'm just used to seeing the VSA with 426 00:39:11,219 --> 00:39:17,760 smaller voltages so I kind of went this way and felt that it was a kind of 427 00:39:17,760 --> 00:39:24,619 Appropriate here. You can you don't really have to do in the VSA would be totally happy to still demodulate your signal, right? 428 00:39:24,619 --> 00:39:30,929 It's just that the power levels look kind of funny. All right having said that 429 00:39:31,849 --> 00:39:38,070 Here's again our lower power result. So this is the ones that we were running that minus 100, right? 430 00:39:38,690 --> 00:39:44,289 And you can see then I'll put powers around a DBM kind of 431 00:39:45,050 --> 00:39:47,050 level we're shooting for 10 432 00:39:47,050 --> 00:39:55,949 and then EVM of minus 20 almost 20 not minus 29 BB looking pretty good right 433 00:39:55,949 --> 00:40:00,070 spectrum and everything you can see a little bit of the silos coming up a 434 00:40:00,070 --> 00:40:04,610 little bit but not too bad now when we go to minus 60 you can kind of see if 435 00:40:04,610 --> 00:40:08,989 you focus on the spectrum here and the bottom left hand corner see the side 436 00:40:08,989 --> 00:40:15,010 lobes came up right the addition channel you can actually I'm gonna switch 437 00:40:15,010 --> 00:40:18,670 between the two you can see also that the constellation became a little bit 438 00:40:18,670 --> 00:40:23,409 rounded again that's the non-linearities at the higher power affecting us 439 00:40:23,409 --> 00:40:30,190 somewhat and then the EVM drop to minus 26.2 right and you can kind of see the 440 00:40:30,190 --> 00:40:34,769 effects of that even in this CCDF plot you can kind of see the the effects of 441 00:40:34,769 --> 00:40:38,769 that I'm gonna switch between the two I can kind of sort of see what's going on 442 00:40:38,769 --> 00:40:46,929 there okay so with that that's the end of the technical presentation for today 443 00:40:46,929 --> 00:40:52,449 before but before I let you guys go let me give you a few video references it 444 00:40:52,449 --> 00:40:57,769 does if you're new to our phase array design or that's me or new to face array 445 00:40:57,769 --> 00:41:03,369 in general not just with pathway system design the there's two videos here on 446 00:41:03,369 --> 00:41:09,610 our YouTube channel from my colleague Dr. Matthew Maka if he covers some really 447 00:41:09,610 --> 00:41:16,030 good phase array theory and you know how to avoid some of the pitfalls and his 448 00:41:16,030 --> 00:41:20,670 videos and then the last two are some playlists from another colleague of ours 449 00:41:20,670 --> 00:41:27,769 Anurag Bhagrava I hope I pronounced his last name correctly sorry Anurag I didn't 450 00:41:27,769 --> 00:41:34,010 so again really good the system view phase array is step by step they're 451 00:41:34,010 --> 00:41:40,889 short videos and he walks you through to other some of the finer details so if 452 00:41:40,889 --> 00:41:46,190 you haven't seen those please I suggest I recommend you send them spend some 453 00:41:46,190 --> 00:41:52,789 time to do that also if you ever are looking for a subject how to do 454 00:41:52,789 --> 00:41:58,849 something in pathway system design even this with just to navigate the user 455 00:41:58,849 --> 00:42:06,190 interface I know I have these short five-minute videos there's 28 of them 456 00:42:06,190 --> 00:42:11,170 just treasure trove of really good information right you're stuck somewhere 457 00:42:11,170 --> 00:42:15,550 oh I wish I could not five minutes just give me five minutes that will walk you 458 00:42:15,550 --> 00:42:18,789 through and some of them are basic and some of them are some fairly advanced 459 00:42:18,789 --> 00:42:26,590 topics you know about five minutes that's all we're asking all right with 460 00:42:26,590 --> 00:42:32,170 that I want to thank you for attending today's webinar and listen listening to 461 00:42:32,170 --> 00:42:36,429 my talk come visit us here's a link if you want more information about pathway 462 00:42:36,429 --> 00:42:42,789 system design and again thank you very much Oh before I leave I want to remind 463 00:42:42,789 --> 00:42:49,389 everybody please tip your moderator and the way you could do that is fill out 464 00:42:49,389 --> 00:42:54,469 their survey they love getting the 100% participation in their survey so please 465 00:42:54,469 --> 00:42:58,750 fill out the survey to make our moderator extra happy today with that 466 00:42:58,750 --> 00:43:03,550 thank you so much and I pass it back to you moderator