High-Performance Compact Diplexer Based on the Alternative Low-Cost AFSIW Technology

In this paper, a high-performance diplexer in the emerging air-filled substrate integrated waveguide (AFSIW) technology is presented. The AFSIW 2.5 dimensionality is exploited in its design to achieve high compactness. A demonstrator is designed with two 4th-order pseudo-elliptic filters centered at 14.5 GHz and 15.6 GHz with respectively 660 MHz and 630 MHz bandwidth (BW). Three replicas are manufactured to evaluate reproducibility. Then, with the objective of demonstrating the AFSIW capability for the New Space applications, thermal and radiated emission (RE) tests are performed. High rejection without spurious resonance, good thermal behavior with variations of 14 ppm/°C, and excellent shielding effectiveness of about 87 dBi are obtained in experiment.