What's the general design procedure for trying to do a wideband impedance match to a device (in this case an LNA) which has very frequency-dependent impedance?
As a personal project, I'm trying to design an LNA for the RTL-SDR receiver which operates on the full 24 MHz - 1800 MHz range (it's very wideband, I know).
As I'm a student I've got the full versions of Agilent ADS, Genesys, and EMPro. Designing the amplifier itself in ADS is pretty easy - plop down an RF transistor, pick a bias point that's stable or near stable, and add neutralization if necessary to bring the transistor into stability.
My question is this: how do I match it to 50 ohms in and 75 ohms out? I know that I should match to the optimum impedance for low noise which I can extract from ADS (or Genesys if I export noise data with my S-paramters).
If the impedance was flat over frequency I could just do something like a Chebyshev match, but the impedance for optimum noise figure is frequency dependent. How do I handle something like this?