Simulation for LNA IP3 and 1 dB com. point using SpectreRF

[Puah Tin Peng]

To Hello,

Whats are steps needed to use SpectreRF to simulate IP3, 1 dB compression point and S parameters on a 1.2 GHz inductive degeneration single-ended LNA?
Thanks.

T.P. Puah

 

[BigBoss]

Re: Simulation for LNA IP3 and 1 dB com. point using Spectre

You should use PSS analysis in SpectreRF with psin source while Amp(dBm) is changed in convenient limits. In this case you do SPSS ( Swept periodic Steady State ) analysis.
When you finished the simulation, SpectreRF automatically will introduce a choise for IPn and Compression points ( either output and output ) .
For LNa's , "Input IPn points ( such as IP3 and IP5 ) are important.

You may select the psin output port and find the behaviour.

Look at SpectreRF Simulation SPSS in User Manual ..

 

[Puah Tin Peng]

Re: Simulation for LNA IP3 and 1 dB com. point using Spectre

To Hello,

What are the best fi and f2 to choose for simulating a 1.2GHz LNA using SpecterRF.

T.P. Puah

 

[activewei]

closely spaced f1 and f2, such as 1 or 10 MHz. There is no best f1 and f2 to use, it is an arbitrary value.

 

[Puah Tin Peng]

Re: Simulation for LNA IP3 and 1 dB com. point using Spectre

To Hello,

In SpectreRF how do you obtain the frequency response of a LNA?
At present I can only think of using S21.
In a CMOS inductive degeneration LNA with a cascode output configuration and a single connected constant current bias, how can I ensure that my design have a flat frequency response?
Thanks.

T.P. Puah