Low-loss, planar monolithic baluns for K/Ka-band applications

The performance of low-loss, planar baluns, specifically designed for MMIC applications operating in the 15 to 40 GHz frequency range, are described. The baluns are realized in both microstrip and CPW configurations with an insertion loss as low as 0.3 dB per balun. This is the lowest reported loss for a monolithic balun operating at these frequencies. These baluns are truly planar with no requirement for multiple dielectric or metal layers.