This project was to design and manufacture a 5th order maximally flat stub RF filter with a cutoff freqeuncy of 2Ghz
A 5th order maximally flat stub RF filter with a cutoff of 2Ghz in QUCS:
Simulation of the Schematic:
The generated PCB layout of the stub filter:
The EM simulation of the PCB layout:
The result of the filter measured with a spectrum analyzer
The final design achieved a very close freqeuncy cutoff of 1.935Ghz compared to the simulated 2.0Ghz.
The freqeuncy response was a little off from the simulated repsonse, but not too bad for a first try
Going forward it could be beneficial to have the filter attenuate faster. I found the draw back from steeper attenuation when simulating was the bandwidth of the filter was reduced, since the bandwidth was more important I sacrificed the attenuation.
Overall I am happy with the results and am excited to manufacture a amplifier PCB with a matching network using open stubs.