чем хорош ADS? Опции

[sargein]

на данный момент изучаю вч моделирование схем в cadence (virtuoso ADE, spectre RF)

в какой проге лучше симмулировать вч схемы - с cadence или в ads?

ну и заодно, может кто подскажет хороший мануал по ADS?

Сообщение отредактировал sargein - Mar 16 2010, 09:05

[grujic]

Sorry for posting in english. I can understand Russian, but my Russian is not that good that I could write an understandable reply.

I have been using ADS and Cadence for some time (years). From my point of view, ADS is very good for system design, RF and microwave problems.
On the other hand, Cadence is probably the best tool for layout, DRC, LVS and extraction. The advantage is also on Cadence side for wide variety of tools available, for both digital and analog flow.

I think that the best approach is to use the best of both worlds - Cadence for schematic and layout and ADS for distributed component modelling. You can easily import extracted netlist from Cadence to ADS and then simulate the whole circuit with harmonic balance, or even transient with convolution.

As always, there is a big BUT. In this case, ADS Momentum is good for EM simulation BUT beware of port calibration! It can lead to significant errors. For example, try to simulate coupled microstrip lines and to deembed the solution. In most cases you will get positive S21 (in dB), which is not possible for passive structure. For most of the structures used in real life, this behaviour does not make any significant difference, but everyone should be aware that Momentum can produce significant (and even non-physical) errors.

As far as I know, HFSS does not have this problem, but it is significantly harder to use.

To conclude, it might be best to export extracted netlist from Cadence (without distributed elements), simulate it in ADS with Momentum results for distributed elements, and check the S parameters for distributed elements in HFSS.