A New Ka-Band Doubly BalancedMixer Based on Lange Couplers

A compact Ka-band doubly balanced diode mixer with new phase relationships is demonstrated. In this design, a novel configuration was employed to have good performance while keeping compact size and simple intermediate frequency (IF) extraction. It is flexible not only in layout design, but also in the reduction of IF inductance. The chip dimension is as small as 0.851.35 mm, implemented by using a 0.15 m PHEMT technology. This mixer has a conversion loss between 9 to 12 dB, a dc-3.5 GHz IF bandwidth, and a good port-to-port isolation in Ka band.