Recommend me a simulator for AM simulations

I plan to do AM simulations (block by block, means mixer, modulator, demodulators...). Which simulator is suitable fo this.

I familiar with (orcad, harmonica (ansoft)). I don't want to do block diagram simulations. I want to try in circuit simulation.

You can do "block by block" simulations in Harmonica(Serenade) as well in OrCAD (preferably 9.2 or higher version). Harmonica needs less computing resource, is faster and is very suitable to simulate rf and microwave circuits, especially oscillators, mixers, modulators and demodulators, small signal amplifiers and even PAs. If you choose OrCAD/PSpice software, is possible to simulate rf-LC oscillators, amplifiers (if you have OrCAD 10, medium PA can be simulated with Q2N3866, BFW16, BFG10, 11, 135, 197, 97, etc. transistors modells) and mixers (I recommend gillbert cell or differential or MOSFET tetrode mixers)

Ansoft's new circuit simulator is Nexxim.

For the complete design flow see http://www.ansoft.com/umc.cfm

Itai