A Design Methodology for a Dual-Mode Coplanar Waveguide Junction Circulator

Circulators with inherent multiband operation are beneficial to low-power and small form factor radars for emerging beamforming and remote sensing applications. In this paper, a design methodology for a dual-mode junction circulator on coplanar waveguide structure is presented. Several magnetic and geometric parameters are shown to have an impact on the standing wave pattern at the circulator junction. Contrasting circulation directions are obtained at the two resonant frequencies of 4.76 GHz and 8.54 GHz with a low insertion loss of 1–2 dB and isolation ratios better than 35 dB and 22 dB for the first and second order modes, respectively.