rf log periodic dipole array antenna company
You will probably get many responses in this thread such as "ADS rulez! Rock and Roll!"
If you are seriously going to purchase any of these tools the companies should be happy to give you 1 month demo licenses. I would put together a series of simple circuits, go through the getting started guides, then simulate the circuits in each to compare the results and how easy it was to get them. You should get nearly the same results, just how easy was it to get there.
Maybe try:
Small signal amplifier (tests linear simulator, tuning, and layout)
Mixer (tests HB simulator with power sweeps, intercept points, etc..)
Oscillator (tests HB phase noise analysis and start-up with transient simulator)
Simple digital divider (really stresses HB and transient simulator convergence)
Diode detector (this simple circuit can test Linear, HB, transient, and even envelope)
Planar coupled line filter (tests microstrip models and planar EM)
Patch antenna (tests far field computations of planar EM)
Just for planar software you have to choose between gridded, shielded analysis (Sonnet, AWR EMSight) and gridless, unshielded (Momentum, AWR AXIEM). The former possibly better for high dynamic range such as filters, and the latter for antennas.
With 3D you have time and frequency domain codes. HFSS is frequency domain. CST has both. Maybe test a patch antenna (to compare to planar simulators), narrowband waveguide filter or resonator, and a wideband antenna such as a log periodic dipole array.
You may want a system level tool too such as AWR VSS.
This may seem like allot of work but if you are going to spend allot of money it should be done.
Me? I like Microwave Office, Sonnet, and CST. With those you have all bases covered and they can all use Microwave Office as a front-end.