Passive Ka-band Spatial Power Synthesis Research Network Characteristics

With the rapid development of military and civilian communication technology in recent years, the technique of electromagnetic signals’long-distance propagation has become particularly important. Power amplifier is one of the core devices of the transmitter. However, the output power of a single microwave and millimeter-wave amplifier chip is limited. In order to achieve long-distance communication, power divider/combiner network is adopted to produce high output power. The main content of this paper includes two parts:firstly, a power divider/combiner network based on waveguide-to-substrate integrated waveguide is proposed. The amplitude phase is good from29GHz to37GHz as can be seen from the simulated results. The insertion loss of back to back structure is about0.7dB. However, due to the processing error, assembly precision and dielectric loss, the measured results has some difference with the simulated ones. The measured insertion loss is larger than the simulated. And the input return loss is larger than15dB from29GHz to37GHz. In order to decrease the power divider/combiner network’s insertion loss, we have developed the structure. The length of the substrate integrated waveguide is cut. So the electromagnetic propagation path is cut which result in the measured insertion loss is decreased significantly.Due to the high combing efficiency of the quasi-optical power combiner, this technology has potential application advantages. In this paper, microstrip patch antenna is used as the fundamental radiation unit to design the device. Firstly, the transmission line equivalent model is adopted to analyze the coaxial feed microstrip patch antenna. Then, the array is placed in the cross section of the rectangle stepped waveguide or the pyramidal horn antenna to constitute the quasi-optical power combiner network. Its working bandwidth is limited by the microstrip patch antenna’s bandwidth. The measured insertion loss is larger than2dB and the measured return loss is larger than10dB from34.7GHz to35.4GHz. In the last, a power divider/combiner network based on quasi-yagi antenna is proposed, the bandwidth is greatly broaden compared with the previous work. The measured results agree well with the measured results. The measured insertion loss is less than1dB and the measured return loss is greater than10 dB which can be seen from the measured results.