Ka-band Waveguide Spatial Power Synthesis Technology Research

The successful application and development of millimeter-wave solid-state system are greatly determined by the system output power. The approach of power combing is an effective solution for greater output power, when restricted by the output of single device. Especially, new technology of power combining is the key of millimeter-wave solid-state power transmitting when the old ways meet some difficulties. A new method of waveguide-based sptial power combining is used in millimeter-wave in this paper. The theory and structure has been analyzed and a project of Ka band power combiner based on overmoded waveguide has developed. In this paper ,filine arrays of waveguide to microstrip transition has designed with low insert loss about 0.6dB in 35GHz~40GHz. Based on the overmoded waveguide, a Ka band power combiner using four MMIC of HP HMMC-5040 has developed. In 38.0GHz~39.2 GHz, the maximal measured saturated output power is about 284mW, and the combing efficiency estimated achieves to 71%. The results suggests promising outlook in performance improvement.