Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

[SOLVED] Input return loss circles. How to generate them?

Status
Not open for further replies.

Canosa

Junior Member level 2
Joined
Mar 23, 2007
Messages
24
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,283
Activity points
1,462
Hi!!! =)

Im designing a CMOS low noise amplifier and would like to generate the input return loss circles of the amplifier for different values. For example -10 dB, -15 dB and -20 dB. I know that if the amplifier is going to be matched to S11* at the working frequency teoretically the input return loss would be infinity, and is represented as a point in the smith chart. So what im looking for is a manner to generate the various cicles for finite IRL.

By the way...
Im using ADS to design the amplifier.

Any sugestions.............???

Best Regards Canosa
 

If I understand your question correctly, you want to generate a Smith Chart ( S11 ) for different values of return loss : -10 dB, -15 dB and -20 dB.
Is that right ?
 

If I understand your question correctly, you want to generate a Smith Chart ( S11 ) for different values of return loss : -10 dB, -15 dB and -20 dB.
Is that right ?

yes! right.
 

There isn't circles such Input Return Loss..
Instead, you should plot Available Power Gain circles or Power Gain circles for different input and output terminations.
Or, you can simulate the circuit to find simultaneously match impedance values etc...
 

There isn't circles such Input Return Loss..
Instead, you should plot Available Power Gain circles or Power Gain circles for different input and output terminations.
Or, you can simulate the circuit to find simultaneously match impedance values etc...

That kind of circles exist. There some article that do that but they not explain how. Their name are constant return loss ( or VSWR) circles or constant mismatch circles. A found the answer in this presentation:
https://pesona.mmu.edu.my/~wlkung/ADS/rf/lesson8c.pdf

A more described approach can be found at E. Collins - Foundations for Microwave Engineering.
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top