Compact Dielectric Waveguide Diplexer for Ku-Band Satellite Communication

In this letter, a compact dielectric waveguide (DWG) diplexer for Ku-band satellite communication is proposed. By an improved diplexer synthesis method, in which preprocessing of the initial iterative polynomials significantly reduces the number of required iterations, the coupling matrix of the proposed DWG diplexer is obtained. And the DWG technology combined with direct coupling at the source is used to realize a miniaturized diplexer design. Therefore, the proposed DWG diplexer not only features a reduced footprint but also supports direct soldering onto printed circuit board (PCB), enabling an easy integration with other devices. A tenth-order diplexer coupling topology is presented, and the implementation of this structure using DWG technology is described in detail. Demonstrated results show good agreement between simulated and measured performance, with the two channel bandpass filters (BPFs) centered at 11.71 and 14.14 GHz exhibiting about 20.67% and 8.91% bandwidth, respectively, and the insertion losses (ILs) of two channel passband are both less than 1 dB.