Design Of Waveguide-Based Microwave Power Combining Amplifier

Power combining technology is a valuable research direction in the microwave technology field. In recent years, high power signal sources are necessary with the development of space communication technology. There are two kinds of power devices used in engineering applications, electric vacuum components and solid-state power devices. Although the electric vacuum components can achieve higher power output, the limitation of size, cost and operating voltage make the electric vacuum components have restrictive in practical engineering application. Compared with the electric vacuum components, the solid-state power devices have great advantages in size, weight, operating voltage and stability. While the output power of single solid-state power device is insufficient to meet the requirement, power combing technology is an effective solution method for the problem.In this thesis, the basic theory of power combining are introduced first, and four power combining structures, traveling-wave waveguide-based; traveling-wave with stepped waveguide; E-plane waveguide T-junction; 3dB waveguide-coaxial bridge power combiner are designed. One of them is chosen to realize the waveguide power-combing amplifier. The main works in this thesis is summarized as follows:This thesis introduces the basic structure and the key technical indexes of power-combing amplifier and theoretically analyzes the gain characteristics and power-combining efficiency. Several major power combining technology are also introduced.Four power combining structures, traveling-wave waveguide-based; traveling-wave with stepped waveguide; E-plane waveguide T-junction; 3dB waveguide-coaxial bridge power combiner are designed and simulated in this thesis.We ultimately choose the power combiner based on E-plane waveguide T-junction to realize the power-combing amplifier, the single power amplifier circuit adopts HMC441LP3 power amplifier chip in the power-combing amplifier. From 8GHz to 12 GHz, the gain flatness in is ?0.6 dB with the gain of the power-combing amplifier ranging from 11 dB to 12.2dB, the saturation output power is 22.9dBm- 23.6dBm, and the power combing efficiency is 72%- 77%.