Rat-Race Coupler
Engineering Projects That Showcase My Expertise
Rat-Race Coupler
A RF coupler used in high frequency communications to split and combine signals. Centered at 1.5GHz, the coupler should split the input signal’s power at port 1 evenly to ports 2 and 4 with 3dB of loss, while allowing no power to exit port 3.
Features
- The geometry of this circuit was calculated using even and odd mode analysis from a set of target S-parameters centered around 1.5GHz.
- The custom PCB was manufactured using RT/duroid 5880 and a PCB mill.
- The S-parameters of the design were simulated in HFSS then tested using a network analyzer.
Outcome
- The magnitude of the output signals matched the theoretical 3dB loss, but the phase shift did not match due to the difference in leg length of the ports. There would have been no error in phase shifting if all the port legs were the same length.