Wide-band ultra-compact coaxial-to-rectangular waveguide and coaxial-to-double ridged waveguide transitions

The new wide-band transitions between 50-Ohm coaxial line and standard rectangular waveguide (18-26 GHz) or double ridged waveguide (8-18 GHz) have been successfully designed and experimentally tested. The fabricated transition for frequency band 18-26 GHz has VSWR less than 1.3. The measured VSWR of the couple of coaxial-to-double ridge waveguide transitions in the back-to-back fixture does not exceed 1.4, while VSWR of single coaxial-to-double ridge waveguide transition is about 1.15. The proposed design of coaxial-to-waveguide transitions is ultra-compact, easy-to-manufacture and it shows excellent electrical performances by mass production.