How to Design an RF Power Amplifier: Class A, AB and B

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To download the project files referred to in this video visit:
www.keysight.com/find/eesof-ho...
This video will provide an introduction to the most basic modes of power amplifier operation by first building a nonlinear device model from scratch and then using this model in a circuit simulation environment to demonstrate various modes of power amplifier operation. This approach will allow us to discover unique insights into the fundamentals of Class A, Class AB, and Class B operation and will also help more experienced circuit designers to understand why it can be so difficult to achieve such idealized performance in practice.

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25 июл 2024

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Комментарии : 53

@charlesmjema5539 7 лет назад

great video with clear explanations

@thuynguyen9348 9 лет назад

very good .tech-imazing- thank you for video.

@Matthew9444 6 лет назад

Fantastic video.

@chao.l6795 2 года назад

thank you for the great content!

@zahrasadeghabadi5128 6 лет назад

hello thanks a lot! i can't download ADS workspace from provided link please help me!!

@sanjeevsoni4962 6 лет назад

Hello , I want to see the equations that are defined in "Equations" Datasets. For example the "dciv" cell has a dataset named "Equation" having "LS_LL" , "LS_Gain" , "SS_Gain" defined in it How I can see definition of these("LS_LL" , "LS_Gain" , "SS_Gain" etc) I don't know how to find them.I searched in google but unable to find them. Please help me in this Thanks

@quyenangcao5744 7 лет назад

can anyone tell me how to choose the point m1 in the IV curve ?

@m.dasvirgenss 3 года назад

I downloaded the template. But how can I use It in ADS? I couldn't open it.

@leventsasmazel6292 2 года назад

Great presentation. Wish to have ADC Software free to the hobbyists.

@moisesafarimugisho9633 3 года назад

Does the workspace work for a Class-C bias condition?

@manjunathsastry7540 8 лет назад

Wow! Extremely well done sir! Can similar analysis, be applied for other classes as well!?

@KeysightEEsofEDA 8 лет назад

+Manjunath Sastry These methodologies are general and can be applied (with some control of harmonics) to achieve more advanced modes of operation. Check out these videos on Class E, Class F and Class J -www.keysight.com/find/eesof-how-to-pa-series.

@manjunathsastry7540 8 лет назад

Keysight EEsof EDA GREAT! Will surely look up! Your videos, provide a greater practical outlook toward what is thought in college. Helps a lot! Cheers!

@dacoda6668 6 лет назад

Great , senior engineers have more useful knowledge than university professors!

@taf209 8 лет назад

Great video!

@ranaalyonsy4671 2 года назад

Thank you so much

@Zanyarsadjadi 3 года назад

many many thanks

@shadabrabbani 8 лет назад

hello sir. what is the parameter _v1 used in diode equation (time 4.08 minutes). i suppose its the voltage across the diode. but i couldn't find this variable defined anywhere in the workspace. i have seen variables like _v1 and _v2 used in equations for MESFET model of GaAs FET, again not defined anywhere. how and where can we use such variables?

@KeysightEEsofEDA 8 лет назад

+Shadab Rabbani These variables represent the voltages across a particular port of a Symbolically Defined Device (SDD). So, in other words, using this device you can define output current (I[1,0]) as a function of input voltage (_v1). This is tremendously useful in modeling, so that’s probably why you have seen it as part of equations for different devices.

@atasarrafinazhad1104 7 лет назад

This is so amazing, one of the best videos I have ever watched in my life. Would you also please explain why the load has real and imaginary part. Since we always calculate and simulate for RL and load-line theory is based on that. But we always have imaginary part in load-pull simulation. Thank you for your time, I appreciate.

@KeysightEEsofEDA 7 лет назад

Great! Glad you find it helpful! Device parasitics are the culprit. These reactive elements occur between the “ideal” current generator inside the device and the actual output terminal (ie the physical drain connection on your IC/package). The goal is to present a reactive impedance externally which is transformed by the parasitic elements so that it is a real load value intrinsically. In this example, the parasitic elements in the model were zeroed out, hence the real load value.

@atasarrafinazhad1104 7 лет назад

yes that is true. We have to add imaginary part for our load in order to cancel out the effect of parasitic capacitance. If the imaginary part is positive it acts like an inductor which resonates with parasitic capacitance Cds and prevents current flow through it so most of the current which is generated by transistor will flow through load.

@nitikasharma7606 8 лет назад

sir i will trying to design the rf rectifier ckt and i need the high frequency diode like HSMS8202 but in my component library it was missing.can you please tell me how to update my component library or get that components . Thanks

@KeysightEEsofEDA 8 лет назад

+nitika sharma Thanks for your question! I suggest you fill out this Assistance form and explain your request and an engineer will follow-up to explain. www.keysight.com/find/eesof-contact

@f.a.w.k.e.s.2415 8 лет назад

Hello. Great presentation sir. Helped me understand the basics of these operations in more depth. Can you tell me that is there a coursework available to learn more about the ADS software. I was not able to find a coursework on the software in my university.

@KeysightEEsofEDA 8 лет назад

+F.A.W.K.E.S. Thanks! There is a lot of coursework to help you learn Keysight ADS! I would recommend checking out some of our eLearning material here. It's a great place to start! www.keysight.com/main/editorial.jspx?ckey=1800357&id=1800357&lc=eng&cc=US

@KeysightEEsofEDA 8 лет назад

+F.A.W.K.E.S. The ADS Cookbook also has numerous tutorial examples that you can work through to learn ADS. www.keysight.com/main/editorial.jspx?cc=US&lc=eng&ckey=2263483&nid=-34360.0.00&id=2263483

@hexmen12 8 лет назад

Hello. I need your help, How to Design an RF Power Amplifier: Class C.with MOSFET ??? The Mosfet use for design is a MRF6V13250H

@chandrasekarsm 2 месяца назад

Did you accomplish it?

@atasarrafinazhad1104 7 лет назад

Hello, When I download the workspace, it gives me PA_Basics_wrk.7zads. How can I import this to ADS ?

@KeysightEEsofEDA 7 лет назад

Hello Ata, Open the file from your ADS tool. From ADS main menu go to File-New-Unarchive and look for where you saved the workspace. You can download a free trial of ADS here: edaapps.software.keysight.com/cgi-bin/eda-evaluation/request.cgi?cmpid=16_CC_090149&product=ads&cc=US&lc=eng&cmpid=zzfindeesof-ads-evaluation

@arslanaltaf7600 5 лет назад

Hi, I had the same issues. Try using winzip to extract the folder then you can easily open in ADS

@saif_hyu 4 года назад

Use unarchive option in ads

@junouyang8881 7 лет назад

What do you mean "by definition, short circuit harmonic termination is required to maintain a sinusoidal voltage waveform" when you were simulating class AB bias?

@KeysightEEsofEDA 7 лет назад

We meant the classical definition of the waveform, where there is a single tone voltage and a rectified current, requires that harmonics are short circuited, meaning zero harmonic voltage and nonzero harmonic current. Without that condition, the voltage could never be a perfect sinewave and the current waveform could never be a partially rectified sinewave.

@junouyang8881 7 лет назад

But LC at best gives roll off... How can one ensure fi where i>=1 gives 0V and also, won't short circuit current @ f0 be minima? But I thought fourier series requires the f0 term for half-rectified signal: people.clarkson.edu/~jsvoboda/Syllabi/EE221/Fourier/FourierSeriesTable.pdf

@KeysightEEsofEDA 7 лет назад

The ideal load is a pure resistance @ 1fo and then a short to all of the harmonics (Vfund does not equal zero, V2-n =0). In the video, the circuit is a resistor in parallel with an LC tank. The tank circuit presents an open at the fundamental, so 1fo current flows into Rload (creating a voltage), and at the same time the tank presents a short at the harmonics, so current flows to the LC tank, not Rload (no voltage). In practice, the LC network needs to be very high-Q do that -- easy in simulation, not so much in the lab. But keep in mind these are idealized waveforms.

@KeysightEEsofEDA 7 лет назад

In practice, a device has parasitics which shift the harmonic impedances away from this R@f1, shorts @f2-n. So, at high frequencies, the required impedances are really reactive -- thankfully no R + ideal tank is needed. But the matching network still must selectively present the right impedance to the device at each harmonic frequency.

@THOMS1111 9 лет назад

Could I have this video as presentation pls

@KeysightEEsofEDA 9 лет назад

pc dell The best way to get the info is to download the workspace referenced in the video. www.keysight.com/find/eesof-how-to-pa

@rahultheytv5347 4 года назад

Great , senior engineers have more useful knowledge than university professors

@csoszadavid4803 28 дней назад

to design their need to learn the reality but the professsors just live in an ideal useless world

@Omega_.3 4 года назад

Gold

@InamKhan-qb7gp Год назад

how I can use this template for my desired transistor? when I insert another transistor in the attached template it does not give the simulation results Kindly answer

@oguzhanyldrm328 6 месяцев назад

did you solve your problem with inserting your desired transistor

@chefboyclakie 8 лет назад

Hi First off I wanna say that this workspace is great. I have a suggestion for making changing the analysis frequency form the the default 1GHz in your workspace easier and more intuitive. Problem 1. There are many data display equations I have found that have the frequency and period value hard coded. For example in simple_power.dds I find the following equations: P_diss_gen_rf=vs((V_t_rf*I_t_rf), t*1E9) V_f=fs(V_t,0,3E9) Pd_pure_rf=integrate(V_t_rf*I_t_rf)/1E-9 So that means every time I want to change my fundamental frequency, I have to change the frequency and period value in every single equation with a hard coded frequency and period. This can tedious and annoying. Problem 2 There is no indication that they should be changed. Therefore for some one who is new to ADS, it can be confusing and time consuming to figure out why the simulations are giving erroneous results since they may not know to change the values in every equation. Suggested Solution It would be better to use a variables like ff=1E9 and tstop=1/ff instead, then tell the user to change this variable if if you want to change the frequency to be analyzed. Therefore the above equations will look like this: P_diss_gen_rf=vs((V_t_rf*I_t_rf), t*ff) V_f=fs(V_t,0,3*ff) Pd_pure_rf=integrate(V_t_rf*I_t_rf)/tstop Then put some comments like "To change the fundamental frequency for analysis, you need to change the ff variable value" I think that will make things better Thanks

@KeysightEEsofEDA 7 лет назад

Thank you, these are very good and well thought out suggestions. Much appreciated!