The Designer's Guide Community Forum

The Designer's Guide Community Forum
https://designers-guide.org/forum/YaBB.pl
Design >> RF Design >> Are these enough for mixer simulation before fab?
https://designers-guide.org/forum/YaBB.pl?num=1195266991

Message started by aboco on Nov 16^th, 2007, 6:36pm

Title: Are these enough for mixer simulation before fab?
Post by aboco on Nov 16^th, 2007, 6:36pm

Hi all,

I am designing a passive mixer with integrated LO buffer using ADS tool, pHEMT process.

Target mixer should have high IIP3, P1dB given a reasonable low LO drive over an RF bandwidth.

I don't have any experience on this.

Simulations I have carried out include:

1. Conversion Gain and Noise Figure: over the RF bandwidth and LO power sweep

2. RF-IF compression (P1dB): over the RF bandwidth and LO power sweep

3. IIP3, isolations: over the RF bandwidth and LO power sweep

4. Ports' return loss

5. SFDR

6. Temperature dependence for all parameters: over a required range of working temperature

(All these include layout affect)

Are these enough for mixer design or is there anyone simulation else should I conduct before having it fabricated?

Any experienced one could give me advice on this design procedure. I would really appreciate your help.

aboco

Title: Re: Are these enough for mixer simulation before f
Post by Berti on Nov 18^th, 2007, 10:43pm

You should also analyze the effect of process variations...
... but in general I think you simulation is only as good as the model you simulate.
Even when your simulator predicts perfect results, your chip might still not work properly.
Therefore I think that a good understanding of the circuit and its potential problems, the
models you use, and the effects not modelled in the simultation (package?, coupling? etc.) is
similar (or even more) important than just to rely on the simulator.

Regards

Title: Re: Are these enough for mixer simulation before f
Post by aboco on Nov 21^st, 2007, 8:53pm

Thank you Berti for advices.
Plz give me example about process variation analyzing.

aboco

Title: Re: Are these enough for mixer simulation before f
Post by Berti on Nov 22^nd, 2007, 7:51am

Usually you design-kits contains models for different process corners. However, for very advanced technologies,
the traditional corner model (fast, slow, typ) is obsolete and you better use statistical (monte carlo) simulation
(you models should containt statistical data).

So, just run the simulations again with different corners models or use monte-carlo simulations.

Regards