Ka-band Broadband Spatial Power Combining Amplifier

Millimeter-wave power amplifier is the key components of the transmitting equipment in the communication system. The power combination technique is an effective solution for greater output power, when output power restricted by the output of single device.Based on software simulation and the processing conditions, this paper presents a new type of power divider/combiner which has two parts, the one part is a combining network based on double probe in H plane coupled to a waveguide, the other is a combining network, which is the combination of waveguide and microstrip. The new power divider/combiner network has the advantages both of the spatial power combining and the traditional circuit power combining. The structure has been modeled and optimized using HFSS electromagnetic simulation package. The four channel network showed a low back-to-back insertion loss of less than 0.6 dB and return loss better than 15 dB at 28-32GHz frequency band, and the maximum combing efficiency is about 90%, which achieves wide-band,low-loss and symmetric power division. The results show that the structure can be applied to high-power multi-device power combining.The gold-wires connection between microstrip and MMICs are simulated in consideration of the loss of bonding practically. Three gold-wires are used to connect microstrip and MMICs, which shows a very low insertion loss of the whole network.