1 00:00:02,000 --> 00:00:06,000 Hi, this video shows how to perform active matching with BetaMatch. 2 00:00:06,040 --> 00:00:10,971 Active Matching means matching towards a source with impedances that may be complex,- 3 00:00:11,021 --> 00:00:14,820 - and where the values will vary across the frequency bands of interest. 4 00:00:17,010 --> 00:00:21,233 It is quite common that Active Matching helps when designing antennas for mobile phones 5 00:00:21,605 --> 00:00:27,015 This is because power amplifiers often have optimum load impedances that are not close to 50 Ohm. 6 00:00:27,856 --> 00:00:30,856 Receivers, on the other hand, are often close to 50 Ohm. 7 00:00:31,126 --> 00:00:38,126 Matching the antenna to only 50 Ohm across all bands will then give poor performance at the TX part of the band. 8 00:00:38,501 --> 00:00:43,183 This can many times be improved significantly by matching towards the actual impedances - 9 00:00:43,233 --> 00:00:48,000 - that the source has at the varous frequencies. This is what is called Active Matching. 10 00:00:50,002 --> 00:00:53,312 In this example we will use the default antenna called "Dual Band". 11 00:00:53,730 --> 00:01:01,790 If it is not already loaded it can be loaded from 'Help Menu -> Load Demo Data' select 'DualBand' and click OK. 12 00:01:03,157 --> 00:01:07,177 We will change the electrical delay to 50 pS ... 13 00:01:09,634 --> 00:01:15,486 and the components we will use are the Murata inductors and capacitors size 0402. 14 00:01:16,247 --> 00:01:23,411 We will set the frequency bands to TriBand EU, which is the 900-, 1800- and 1900MHz bands. 15 00:01:23,883 --> 00:01:30,675 We will optimize this antenna with a normal source impedance of 50 Ohm. We will start a 4 components optimization - 16 00:01:34,432 --> 00:01:42,047 The optimization is now finished as you can see the best 4 component network is a T-network with only 3 components. 17 00:01:42,798 --> 00:01:46,656 We store these results into 'Memory 1'. 18 00:01:47,307 --> 00:01:54,571 The results look good and from the accepted power data we can see that we have 78% or more at the low band - 19 00:01:54,621 --> 00:01:58,633 - and 70% or more at the upper bands. 20 00:01:58,729 --> 00:02:05,242 but, assume that we use this matching network and that we do active measurements on our phone - 21 00:02:05,342 --> 00:02:10,402 - and then we find that TRP at the 900MHz band was at least 2dB lower than we expected. 22 00:02:10,892 --> 00:02:15,912 We then did a push-pull measurement of the power amplifier and the found that the optimum load impedance - 23 00:02:15,962 --> 00:02:22,625 - at the TX part of the 900MHz band is not 50 Ohm but rather 20 - j20 Ohm. 24 00:02:24,579 --> 00:02:29,689 Let us enter this new load impedance and see what accepted power we can expect. 25 00:02:34,548 --> 00:02:45,670 870MHz ... 20 Ohm ... -j20 Ohm. Then at 925MHz we have 50 Ohm again. 26 00:02:51,431 --> 00:02:55,488 We can compare these results with the previous results with 50 Ohm. 27 00:02:56,290 --> 00:03:05,758 We can see that we have dropped from 78% to 42% at 880MHz, which is a drop of more than 2.5dB. 28 00:03:06,910 --> 00:03:12,571 It is clear that our design, that worked well with 50 Ohm load, is not going to work well at all with a - 29 00:03:12,622 --> 00:03:17,581 - power amplifier that has an impedance that is that far from 50 Ohm. 30 00:03:17,982 --> 00:03:25,396 So, what we will do now is to run another optimization where the impedance of the PA is also entered. 31 00:03:25,446 --> 00:03:29,494 So we start another 4 component optimization now ... 32 00:03:41,377 --> 00:03:47,188 This new matching network has similar performance as the previous matching network at the band edges. 33 00:03:47,589 --> 00:03:52,749 But this new matching is now matched towards the actual impedances of the working phone. 34 00:03:53,751 --> 00:04:02,217 This means that we should have increased our TRP at the 900-band by more than 2dB with this new matching network. 35 00:04:05,123 --> 00:04:10,734 We can also se in the Smith Chart that the low band - 36 00:04:10,784 --> 00:04:16,294 - that used to be here with the 50 Ohm match now has been shifted and is located - 37 00:04:16,344 --> 00:04:26,865 - here between 20 - j20 Ohm and 50 Ohm in order to obtain a good match at the low band for both these impedances. 38 00:04:35,732 --> 00:04:39,439 That concludes this demonstration of Active Matching with BetaMatch. 39 00:04:39,790 --> 00:04:44,339 My name is Max Landaeus and my contact details are on the screen right now. 40 00:04:44,749 --> 00:04:51,061 Feel free to contact me if you have any questions or other feedback. Thanks for your time and attention.