Optimization Technology of the Microwave Diplexer Based on Spatial Mapping Algorithm

Abstract

An optimization technology of the microwave diplexer is proposed in this paper. The spatial mapping algorithm has been adopted to analyze and design the microwave diplexer, and the mapping relationship between the physical circuit (accurate model) and the schematic circuit (rough model) has been established, and then the least square method has been applied to fit it. Moreover, the inverse mapping method has been applied to guide the design of the accurate model by the optimization of the rough model. To verify the presented optimization technology of the microwave diplexer, a diplexer with the center frequencies of 1.85 GHz and 2.4 GHz respectively is designed, optimized, and fabricated. The measured results show that the insertion loss is about 0.8/1.5 dB. The measured output return loss is greater than 20 dB. Moreover, the measured isolation between two channel is greater than 35 dB. The total size of the fabricated diplexer is only 0.25λg 0.2λg. The measured results are in good agreement with the simulated ones, which was able to demonstrate the feasibility and advantage of this algorithm in designing microwave diplexer circuits.