Tutorial-37: S-Parameter Simulation of Active Circuits

[@ajithsrighakollapu3569]

Thanks a lot for posting this quality content for free , it really helping me .

[@BhargavaAnurag]

Glad it was helpful!

[@yuchansong8725]

Can't wait to watch your video about designing LNA. Thank you so much for your video and for sharing your knowledge!

[@BhargavaAnurag]

Thanks for watching!

[@MrRijubratapal]

Thanks for starting active circuit design. Glad to know that you will cover Amplifier & LNA in detail soon. :)

[@BhargavaAnurag]

Hi Riju, This tells me that you were listening to the tutorial carefully...😊 Yes, I plan to cover active & passive circuit designs in the near future...👍

[@antenna_designaaa664]

Your topics really help me to learn ADS . Thank you very much for your time,

[@BhargavaAnurag]

Glad to hear that

[@Miguelocod]

Hi Anurag, first of all thanks for providing such useful tutorials for free to everyone, your help is really valuable. I have found that many vendors provide both S-parameters files with measurements and SPICE models for their devices. Could you comment on which model should be used for simulation? Are there any advantages on each model?

[@BhargavaAnurag]

Hi Miguel, It really depends on what type of circuits are you designing and both type of models have their own pros & cons. S-Par files are usually OK for LNA kind of designs as non-linear simulation is optional, considering they are used in receivers and power levels usually will always be low so you can live with SnP files. However, if you want to see non-linear effects then SnP file for the device is of no use to you and you should use nonlinear (SPICE) models. Just remember that every modeling will have some or the other compromise and your eventual results will be subjected to the quality of models vendor provides. If you doubt a model accuracy or quality then you either need to do your own modeling or hire consultancy services of some company to develop more accurate model for you.

[@Miguelocod]

@@BhargavaAnurag great, thanks!

[@binhpham5200]

Hi Mr. Bhargava, decent work and concise explanations there. May I ask why we need both StabFact and StabMeasure blocks to evaluate the stability of the circuit, because from some textbooks and also I learned at school, only K factor suffices? And why you prefer Mu and MuPrime over the other two? Regards, Binh

[@BhargavaAnurag]

Hi, StabFact or K is only necessary condition but not sufficient and for stability you need necessary and sufficient condition and that's why you need StabMeas as well.

[@italo.xaviercp]

This one was very helpful! I would like to ask some questions. When you get the Zin (7:12) there is a way to give me the best option for the capacitance and inductance of the matching circuit, or I must do it manually with some calculations? The values on the table are exactly the necessary impedance for giving me the input matching depending on the frequency of the Transistor any correlation of Zopt? With the circle graphic, I can include the gain and the noise, so the match of them would be the best impedance (this impedance is correlated to the input or output of the circuit?), so with this in mind, I do not need to evaluate the Zin and Zout commands? Regards Anurag!

[@BhargavaAnurag]

Kindly see videos under RF Design Tutorial playlist. There are 3 videos on impedance matching covering all aspects and they will be useful. You can either use Smith Chart tool or Impedance Matching synthesis as demonstrated in the tutorials.

[@shadabrabbani]

Your videos have helped me a lot in understanding ADS. I have simulated several microwave passive circuits and have used SP simulation in my several designs. Please make a video on LSSP (Large signal S-Parameter) simulation, as required for obtaining the input impedance of a rectifier circuit used in RF Energy harvesting. I am yet to find any good video or literature on this topic.

[@anveshpandey9817]

did you find any?

[@raowaqas1445]

did u find?

[@peimanparand]

awesome

[@adnannadeem6223]

Thank you for your informative video Anurag sir. I want to plot S11 of a rectifier input for different input power levels but my S11 results the same for all different power levels. In VNA I checked that for every input power level my S11 gets shifted because of the non-linearities of the diodes in the rectifier circuit. But I am unable to get different S11 plots for different input power levels. Please guide me in this context.

[@BhargavaAnurag]

Try LSSP instead of Small Signal S-Parameters.

[@saurabhshukla1490]

Sir Can you tell me, how to get device in stable zone? .As per your circuit simulation,stability factor is less than one.

[@BhargavaAnurag]

Good question Saurabh...Stay tuned for upcoming tutorials for the same...!!😊

[@saurabhshukla1490]

@@BhargavaAnurag Yaa sure Sir..I am waiting for your upcoming tutorial..

[@naingaunglwin833]

Do u have notes related with ADS like books that are written by you . I want to study yours.

[@BhargavaAnurag]

Hi Naing, I haven't written any commercial book till now but one simple book which I wrote sometime back is available via Amazon: www.amazon.com/ADS-Example-Book-Focused-Microwave/dp/1539542211/ref=cm_cr_arp_d_pl_foot_top?ie=UTF8

[@yuchansong8725]

Hi, may I request any references about how to design DC block and DC feed?

[@BhargavaAnurag]

Hi Yuchan, DC Feed could be an RFC (in low frequency till ~1-2GHz) or a high impedance lamda/4 line as shown in the LNA design video. For DC block you could use a Capacitor as this can be designed to be part of your matching network like done in the LNA design tutorial serving both matching as well as the DC blocking purpose. Hope this helps..

[@alirezajafarieh226]

👌👌👌👌👌👌✌✌✌✌

[@BhargavaAnurag]

Thanks for your feedback...👍