High-Yield Waveguide Diplexer for Low-Cost E-band 5G Point-to-Point Radio Links

This paper presents the design and realization of a high-yield tuning-less waveguide diplexer and a high-gain lens horn antenna for 5G point-to-point fixed-beam communications at the frequency ranges of 71/76 GHz and 81/86 GHz (E-band). The diplexer is composed of two bandpass filters based on the combination of a low-pass filtering function and a high-pass structure. The diplexer provides very relaxed fabrication tolerances. A prototype has been fabricated and measured showing return loss better than 20 dB and attenuation levels higher than 60 dB. The insertion loss is better than 1 dB. A lens horn antenna which provides more than 38 dBi gain is utilized to provide high directivity at the same frequencies. The proposed sub-system combines the advantages of high-performance and simple mechanical assembly finding, it especially attractive for 5G applications due to the reduced fabrication cost.