Wideband Planar Crossover Using Two-Port and Four-Port Microstrip to Slotline Transitions

The design of a wideband crossover that includes a pair of two-port and another pair of four-port microstrip-slotline transitions is presented. The utilized transitions are designed such that the resultant planar crossover has high isolation and return loss, and low insertion loss and deviation in the group delay across a wideband. The simulated and measured results of a developed 9 mm × 13 mm crossover on a substrate of 10.2 dielectric constant show less than 0.5 dB insertion loss, more than 15 dB return loss, more than 15 dB isolation and less than 0.1 ns deviation in the group delay across the band from 4.8 to 7.2 GHz (40% fractional bandwidth).