Marki Microwave RF/microwave surface mount diplexers route signals by frequency into low-pass and high-pass ports around a defined crossover frequency, offering broad coverage, low insertion loss, high out-of-band rejection, and strong port-to-port isolation. Their resonance-free response makes them well-suited for Tx/Rx antenna sharing, LO/RF separation in mixer-based architectures, and use as reflectionless filters by terminating the unused port to absorb out-of-band energy rather than reflect it.