Design of Ku-Band Filters and Diplexer for a Heterodyne Transceiver Using Coupled Open-Loop Resonator Cells

This manuscript presents the design of two microstrip coupled open-loop resonator bandpass filters using a square loop-resonator, also know as splitring resonators, to be used in radio frequency Front-Ends. In addition, a microstrip diplexer using these cells is also detailed. The devices operate in ku band, using the frequencies 11.7–12.2GHz, to the receiver channel, and 14–14.5GHz, to the transmitter channel. All the design is made considering low-cost industrial manufacturing tolerances. A Monte Carlo analysis is performed to verify the sensibility of the device due to the manufacturing capabilities. The measurement and simulation curves agree with a good level of acceptance, diverging each other in just 1.7dB in the passband, in the worst case.