RF Isolators & Circulators Molex RF Isolators and Circulators offer frequencies from 380MHz to 40GHz and have drop-in and surface-mount options. Molex RF Isolators and Circulators feature designs as small as 6mm and provide optimized electrical performance, unit-to-unit consistency, and a wide frequency band that ensures the ability to combine multiple bands in a single radio in new designs. Suitable applications for these isolators and circulators include antenna array systems, base transceiver stations, radio access networks, and laboratory test applications.