Novel transition between microstrip and slotline

A novel reduced-size microstrip-to-slotline transition is proposed by using planar lumped-element parallel LC circuits to replace /spl lambda//4 transformer structures. The transition is simulated by commercial software HFSS and CST Microwave Studio. It exhibits an insertion loss less than 1 dB in the frequency band 4-9.3 GHz. Specifically, lumped-element transition with 1/10 the size of conventional ones can be achieved.