Ku-band Pulsed Solid-state Power Amplifier Developed

Transmitters are key parts in microwave and millimeter-wave systems. Recently, duce to the improvements of semiconductor power device technology's and dropping of costs, more and more solid state transmitters have been adopted by various microwave systems. However, as a single device usually gives out little RF power, effective approaches of RF power combing are needed to obtain greater output power for these application systems. In this thesis, Ku band solid state power combined amplifier (SSPA) is studied and a Ku band SSPA with 40W pulsed peak power output is developed with applying waveguide-based spatial power-combining approach, with considering the current technology and application requirements.Being concerned about the output power, pulse rising time and miniaturization of the SSPA, this thesis carries out the following works. The SSPA is divided into the microwave power amplifier and the pulse modulator. The waveguide-based spatial power-combining technique is used in the amplifier to obtain greater output. And the drain of the GaAs FET power amplifier chip is pulsed to get fast pulse rising time. Microwave passive circuit design takes key role in concerning miniaturization.Compared with the traditional E-plane waveguide combiner, this thesis presents a new type of H-plane waveguide structure as power dividing/combining network. With optimization and careful improvement, this waveguide structure has reduced the volume of the passive circuit with a low insertion loss and laid a foundation for miniaturization.The amplifier with more than 40W pulsed peak output power over 13~14GHz is processed in 182.4×74×60mm3, so the miniaturization of equipment is realized. The tested data of the amplifier show that the average pulsed peak output power is 43.1W over 13~14GHz, the power gain is more than 36dB, and the pulse duration is 1.02μs with both rise time and fall time are 30ns. The average combination efficiency in the band is about 80.4%.