| GaN wide bandgap semiconductor microwave power devices with its high current density, high power density, high breakdown voltage and high power added efficiency, have become a hotspot in many countries. Its excellent characteristics determine that the GaN devices would have broad application prospects in the field of military and civilian microwave powers. With the development of GaN HEMT device technologies, the goal to achieve high-power and even high-frequency microwave amplifier production has been the one that everyone wanted to pursued. Basing on above background, in this dissertation the studies were focused on the development of C band 30W internally matching amplifiers based on the GaN HEMT. The main results are as follows:The key design technologies were researched about the HMET power amplifiers, such as relationships between the type of work and efficiency of the device, stability analysis, load-pull theory principles and analyzing the matching network structure on the bandwidth performance and design method. On this basis, the internally matching network of the power amplifiers and the test fixture were designed:achieve the optimum impedances by analyzing the die model; taking into account that the performance of parasitic parameters of the tube can not be ignored, it is used that the structure of two stages consisting of T matching network and λ4 microstrip line for the results of simulation; design the actual device parameters used in the internally matching network with three-dimensional simulation technology; during the design of the test fixture, it should be to ensure the stability of the device without compromising its microwave performance, and it is focused on analyzing the capacitor RF performance impacts and loss factors, such as DC-blocking capacitors, RF bypass capacitor and decoupling capacitors used for different requirements.Finally, the die and the matching element were mounted in the tube. After analysing the bias point, the resonance point and the matching capacitor, the test results at Vds= 32V, Ids= 100mA conditions within the range 5.3GHz-5.9GHz were as follows:the test results on a calibrated display pieces are that the linear gain is greater than 12dB, and get the maximum value 14.5dB at 5.9GHz, at 1dB compression point output power is greater than 45dBm, at 3dB compression point PAE is greater than 46.4%; while tested on the display fixture, because of the stability network the devices achieve absolute steady state, and the linear gain is greater than 12dB, and get the maximum value 13dB at 5.7GHz, at 1dB compression point output power is greater than 44.7dBm, at the same time the return loss is less than -6dB, at 3dB compression point PAE is greater than 47.2%. |
