Millimeter-wave CMOS miniature resonator and coupler

New millimeter-wave cavity resonator and broadside-coupled Lange coupler have been developed in a 0.25-mum CMOS process. The resonator employs a capacitively loaded cavity topology effectively implemented using the CMOS multi-metal-layer and via-hole structure. The CMOS cavity resonator, including two coupling apertures and microstrip feed-lines, occupies an area of 2 mm times 1.4 mm times 6.28 mum. It resonates at 30 GHz with a corresponding insertion loss of 2 dB and unloaded quality factor of 22.2. The broadside-coupled Lange coupler exhibits -3.3 to -3.35 dB through, - 3.3 to -3.7 dB coupling, more than 12 dB isolation and 15 dB return loss across 25-35 GHz while occupying only 217 times 185 mum of chip area.