A modular microwave power combiner having a plurality of identical microwave diode amplifier circuits grouped in sets within the body of a modular unit which are electrically coupled in parallel to a central cavity sized to be resonant at a single frequency to minimize mismoding thereby enhancing combiner...http://www.google.co.uk/patents/US4175257?utm_source=gb-gplus-sharePatent US4175257 - Modular microwave power combiner
