HELP !SIMULATION ADS2003A

[ahmer saeed]

I have designed my LNA using atf36077 at a frequency 2 ghz ,NF<3,GAIN=12DB. I have simulate it using s-parameter simulation and find out the NF &gain&stability.
Now,I want to simulate it on ads2003a by applying the input signal with a defined power and frequency and observe its result.Like we do practically by applying signal thriough signal generator and observe it on spectrum analyzer.

 

[lebed]

You can using S-Parameter simulation to get matching, gain and NF.
Good example is 1GHz_LNA_prj.
P1 db (I think) you can simulate with harmonic balance.

 

[YiPing]

I think that rf singal of LNA is small singal,simulation with harmonic is insignificantbalance. If rf singal of LNA is large signal, you should use limiter.
Pl take a look on:
2GHz BJT Low Noise Amplifier
Location: \examples\MW_Ckts\LNA_prj
Objective
This example shows a simple procedure for designing a low-noise amplifier. The specifications are: 3 V supply, 2 mA collector current, lowest noise at 2 GHz, gain > 10 dB at 2 GHz, input and output reflection coefficients better than -10 dB at 2 GHz and unconditionally stable.

Large Signal Amplifier Simulations
Location: \examples\MW_Ckts\LargeSigAmp_prj
This example provides details on how to use Advanced Design System (ADS) to characterize large-signal 1GHz RF amplifiers. It shows how to determine gain compression, third-order intercept (TOI) level, saturation output power, the output voltage spectrum, power dissipation and dynamic load line.
Notes
1 The user can use either a built-in IP3 function or write an equation in the two-tone test to calculate IP3.
2 Simulation used: Harmonic Balance, Gain Compression, DC.

 

[BigBoss]

You have to use Harmonic Balance simulation to find output power and its harmonics etc.
Define a certain frequency in "Single tone signal source" and terminate the LNA with a convenient "port" ( e.g. port or resistor )
Fill the the neccesary "frequency" and other fields in HB controller and simulate.

But the best way to use " Amplifier design Guide" that will establish a suitable setup for your amplifier.In this setup, all neccesary outputs, inputs and characteristic of an amplifier are drawn . It's not so difficult..

It will characterize your amplifier from A to Z...

Good Luck

 

[ahmer saeed]

My LNA is small signal ,can harmonic balance is used for small signal?
if no,then tell me the alternate.

 

[BigBoss]

My LNA is small signal ,can harmonic balance is used for small signal?
if no,then tell me the alternate.

Yes, HB is used also for small signals. Doesn't matter..
It's always possible to use" transient simulation" but don't trust ADS Transient simulator too much. The best transient simulator is still Cadence.. ( if you may do a well modelling )

 

[activewei]

To ahmer saeed: what is your model for your LNA? If your model is a linear model (using s2p), you can get the response of "applying signal through signal generator and observe it on spectrum analyzer" with harmonic balance simulation, using P1tone as input port. You can sweep the input power easily. However, with linear model, it is impossible to tell what is the P1dB , TOI3... (all non-linear behaviour) of your LNA.
Please take note!

 

[v4eda]

To ahmer saeed: what is your model for your LNA? If your model is a linear model (using s2p), you can get the response of "applying signal through signal generator and observe it on spectrum analyzer" with harmonic balance simulation, using P1tone as input port. You can sweep the input power easily. However, with linear model, it is impossible to tell what is the P1dB , TOI3... (all non-linear behaviour) of your LNA.
Please take note!

i do not think it's possible to do harmonic balance analysis on a s2p file!
if you need to do harmonc balance you need the nonlinear/bias dependent model of the device in question and if the model parameters are available from the data sheet then those can be used in the generic nonlinear model available in ADS

 

[myicejade]

you can try to use RF designer of ADS ,there are many templates of LNA ,maybe they can help you .