Ku-band Broadband And Efficient Power Amplifier Research

With the development of satellite communication technology and the market continues to expand, the demand for the broadband, highly efficient high-power solid-state power amplifier is increasing. In the situation that the output power of a single can't meet the system requirements, power combining technology is often used to integrate multiple solid-state power devices in a power combiner amplifier to obtain high-power output. In order to obtain higher combining efficiency and integration more solid-state devices, the research focus of power combining technology is transferring to spatial power-combining from the traditional planar circuit combining methods. In recent years, with the vigorous development of spatial power combining technology, the ways of spatial power combining are variety. As representative example: quasi-optical synthesis, combining in waveguide, slotted waveguide combining, radial waveguide combining, chain-style combining and so on.The objective of this dissertation is to present several Ku-band broadband, high efficiency, multi-channel spatial power combiner programs which meet the needs of practical engineering applications to address the Ku-band satellite communication systems in high-power output problem. The main results of this dissertation are as below:1. A Ku-band broadband, highly efficient four-way spatial power combing network which is consisted of a pair of Ku-band reduced-height waveguide to microstrip 00 probe transitions connected with Ku-band broadband reduced-height waveguide ET branch to achieve four-way splitter. This four-way power combining network can work in the Ku band (12GHz-18GHz), the efficiency is more than 94%. Then take advantage of this network and complete a Ku-band four-way power combining amplifier using power MMIC to promote the power FET power MMIC. In the 15.7GHz-16.2GHz frequency range, the measured maximum output power is 46.19dBm (41.6W). The measured combining efficiency is up to 78.2%; The maximum power-added efficiency of 16.6%, and the required DC power is 237W-250W. With advantages of high output power, simple structure, good heat sink, and small size, this Ku-band four-way power combining amplifier can be used as a single power-combining amplifiers or power module.2. Connecting two Ku-band four-way power combining amplifier used as power module with waveguide E-T branch, a 70W output power combining amplifier has been realized in 15.7GHz-16.2GHz. At the same time, it proves that the previous design of Ku-band four-way power combiner amplifier has good modularity once again.3. It also presents a Ku-band broadband, highly efficient eight-way spatial power combining network which is used of two Ku-band reduced-height waveguide to microstrip line transitions connected with a Ku-band broadband waveguide ET branch to realize eight-way power dividing. The measured efficiency of this network is above 83% in the whole Ku band (12GHz-18GHz). Then, taking advantage of this network and eight domestic power MMICs, a Ku-band broadband eight-way spatial power combining amplifiers has been developed. In the whole Ku band (12GHz-18GHz), the measured CW output power of this eight-way power combining amplifier is up to 45.6dBm(36W), the measured maximum combining efficiency is above, the maximum PAE is 16.8%, and the DC power consumption is less than 200W. With advantages of wide band, high efficiency, compact structure, easy processing, good heat sink, etc., this Ku-band eight-way power combining amplifier can fully meet the practical engineering requirements.