Coplanar Stripline Switch Based on Lattice Circuit with Even Mode Suppression

Coplanar Stripline (CPS) has some advantages in integrated circuit layout, but it is not commonly used because higher order modes are easily excited that degrade the circuit performance. CPS switches are required for tunable antennas and reconfigurable systems. This paper describes a CPS switch with a theoretical insertion loss of 0 dB, a return loss of infinite dB, and infinite isolation. The switch relies on a method to suppress the higher order, even mode that was recently published. Measured results demonstrate an insertion loss of 0.1 dB, a return loss of 40 dB, and an isolation of 25 dB.