Design of Ka-band half mode substrate integrated waveguide (HMSIW) mixer

In this paper, a half mode substrate integrated waveguide (HMSIW) mixer at Ka-band is proposed. A newly developed 3-dB cruciform HMSIW coupler was employed to add LO and RF signal on Schottky diodes. Size of the mixer is more compact than traditional narrow-wall aperture coupling SIW or HMSIW configuration mixer. The mixer was designed and fabricated on Roggers 5880 substrate with beam lead Schottky diodes. In experimental test, conversion loss was measured in frequency range from 34 to 38 GHz under different LO power. The conversion loss of 8.2 dB was reached at 36 GHz.