A wideband radial substrate integrated power divider at K-band

A wideband 1:7 radial power divider for operation at K-band is proposed. The divider features a radial substrate integrated waveguide (SIW) cavity enclosed in a multilayer printed circuit board (PCB) as well as microstrip matching structures and feed-lines on the top and bottom layers. The divider is designed using standard high-frequency substrate. Including the outer vias, the divider cavity has a diameter of about 7 mm. Thus a compact design is achieved. Measurement and simulation results are presented. The measured -10 dB reflection bandwidth of the divider is 9 GHz or 45% with a center frequency of 20 GHz.