Ku Band Diplexer Antenna for Data Relay Satellite Uplink in ITU-R

This work describes a substrate-integrated waveguide (SIW) based Ku band diplexer antenna (DA) for data relay satellite (DRS) low and medium data rate uplink. Designing diplexers that operate at closely spaced frequencies is difficult. The DA’s bandwidth (BW) in the proposed design ranges from 12.6 to 15.2 GHz. According to the ITU-R standard, one of the DA’s ports operates between 12.75 and 13.25 GHz, while the other operates between 14.5 and 14.75 GHz. The proposed antenna achieves both high gain and wide BW concurrently, which is challenging to do in DA. The radiation caused by the coupling between the proximity modes is excited using a back-to-back triangular SIW and square slots. This SIW DA radiates with 25 dB port isolation and linear polarisation at broad frequencies. It is small, and the slot-loading effect reduces the antenna size. It is suitable for DRS’s low and medium data rate uplink multiplexing applications since both ports obtain a wide BW of 20.14 percent at frequencies between 12.6 and 15.2 GHz and a gain of 4.5 dBi. The smaller ECC (less than 0.4) ensures mutual coupling between ports and improves performance and data transmission