I've edited it, but generally you don't want to have problems with mirror images getting through and creating spurious responses. Real world RF filters don't have infinitely steep edges, so initially I figured a 4 Ghz low pass filter would have enough loss by 5 Ghz to get the job done. I revised to to a 5 Ghz low filter, and a 7-12 Ghz Local Oscillator to give the filter an easier job. Also, the lower the swing in percentage terms for a VCO, the easier it is to work with.
So the signal path in receive mode would be:
N connector / 20 dB 100 watt pad / Switched attenuator / Low pass filter / Front End diodes / Mixer / Router board for DSP
Alternatively, there's usually a second path that skips the attenuator, with a lower maximum power level.
The reverse path would work for generating signals from DC (almost) to 5 Ghz.
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I've edited it, but generally you don't want to have problems with mirror images getting through and creating spurious responses. Real world RF filters don't have infinitely steep edges, so initially I figured a 4 Ghz low pass filter would have enough loss by 5 Ghz to get the job done. I revised to to a 5 Ghz low filter, and a 7-12 Ghz Local Oscillator to give the filter an easier job. Also, the lower the swing in percentage terms for a VCO, the easier it is to work with.
So the signal path in receive mode would be:
N connector / 20 dB 100 watt pad / Switched attenuator / Low pass filter / Front End diodes / Mixer / Router board for DSP
Alternatively, there's usually a second path that skips the attenuator, with a lower maximum power level.
The reverse path would work for generating signals from DC (almost) to 5 Ghz.