Extending the bandwidth of resistive terminations
Chris Bartram G4DGU
Might it be feasible to make a narrowband attenuator for 5.7 using one of the 4GHz-rated flange-mount chips with some tuning stubs on a bit of microstripline PCB? Then the requirement would only be to >3.4GHz, which might be easier to achieve from my pocket-money allowance.Yes. However, it might be more difficult if the load has a strong resonance at 5.6GHz.
Measure the impedance the attenuator is presenting, and then design a low (loaded) Q matching network. A classic approach would be to use a (pseudo) low-pass network in the same way as is often done for amplifier designs. It might be easier to visualise the network if the impedance information used is broadband, covering, say, an octave spanning the desired operating frequency of the load.
-- Chris Bartram Luxulyan, Bodmin, Cornwallh chris@...