Broadband 55 – 95 GHz microstrip to waveguide transition based on a dielectric tip and a tapered double-ridged waveguide section
Résumé
As applications in E-band (60 - 90 GHz) are gaining increasing commercial interest, a full-band, low-cost and high performance microstrip to rectangular waveguide standard (WR12) transi-tion is desired. The presented design covers a bandwidth from 55 GHz to 95 GHz thanks to smooth impedance transitions. A dielectric tip is machined at the end of the microstrip line to couple with a double ridged waveguide section, which is then linearly tapered to a standard WR12 section. Measurements on back-to-back transitions confirm wideband operation beyond E-band with a 3.6 dB average insertion loss (1.8 dB per transition) and return loss lower than 10 dB in the 55 to 95 GHz frequency range. Additionally, group delay is measured showing broad-band operation in line with the simulation.