Air-to-dielectric-filled two-hole substrate integrated waveguide directional coupler
Résumé
A two-hole directional coupler consisting of an air-filled substrate integrated waveguide (AFSIW) coupled to a dielectric-filled substrate integrated waveguide (DFSIW) is introduced and studied for the first time. The design of the proposed two-hole coupler, based on different dielectric-loaded substrate integrated waveguides (SIW) and on multilayer printed circuit board (PCB) process, is presented in detail with its theoretical foundation. The proposed coupler is of interest for monitoring high performance, self-packaged and low-cost millimeter-wave substrate integrated systems based on AFSIW. For demonstration purposes, a forward coupler operating in the Ka-band satellite uplink frequency band (27 to 31 GHz) has been designed and fabricated. In its frequency range of operation, it achieves measured insertion loss, coupling and isolation of 0.28 ±0.15 dB, 20.8 ±0.24 dB and 46.76 ±3.92 dB, respectively