Research On Ka-Band Transceiver Components Monolithic Integrated Circuits

The microwave and millimeter-wave monolithic integrated circuit (MMIC), which is fabricated by GaAs pseudomorphic high electron mobility transistor (PHEMT) process, has the advantages of excellent high-frequency performance, good power character and low noise property. Therefore, it is widely used in millimeter-wave communication systems, millimeter-wave radar systems, and so on. In this thesis, some Ka-band transceiver componets MMICs are researched. Finally, they are fabricated by 0.2μm GaAs PHEMT process or 0.15μm GaAs power PHEMT (PPHEMT) process, respectively. At the same time, the technology of integrating multi-function unit circuits on a single-chip,stability analysis method of nonlinear circuits, and the technique of improving component stability are also studied. The major contents of the thesis are:(1)The nonlinear stability analysis method is studied. By adding some variable terminal impedance, the method has been improved. It makes the simulation circurmstances closer to the actual use conditions of MMIC.(2) A Ka-band sub-harmonic image rejection low noise down-converter MMIC is studied and designed. This chip integrated a low noise amplifier unit and an image rejection balanced mixer, and it performs an integration of millimeter-wave multi-functional unit circuits. Its size is only 2mm×1.5mm.The low noise amplifier unit utilizes two-stage common-souce FET topology. The DC-bias is suppled by resistance voltage divider. The image rejection balanced mixer unit consists of two compact Marchand Baluns, some PHEMT resistance mixers and a Lange coupler. In the design procedure, the improved nonlinear stability analysis technology is used and instructs us to design the circuits between low noise amplifier (LNA) unit and mixer unit. The measurement results show the convertion loss of the whole chip is less than lOdB and the image rejection ration is more than 15dB over 30～40 GHz.(3) A Ka-band 400mW power amplifier (PA) MMIC is perfomed. Based on the on-chip power combination technology, the small signal gain is more than 6dB and the saturation output power is more than 26dBm at 35GHz.(4) A Ka-band one watt-level PA MMIC is designed and fabricated. The on-chip power combination technology, the simulation load-pull technology and the improved nonlinear stability analysis technology are utilized. Especially, at the output port, a novel idle circuit is designed to suppress low frequency signal and second harmonic. The measurements show this MMIC has more than 15dB small signal gain over 28～31GHz and more than 30dBm saturation output power over 28-29GHz.(5) A method for improving the broadband phase characteristic of the conventional CS/CG active Balun in MMIC is studied. Based on this method, a novel ultra-wideband balanced doubler is performed. The MMIC consists of a CS/CG Balun, two boubler FETs, a distributed amplifier unit and a two-stage CS amplifier. Its operation bandwidth is more than four octaves. The measured results show its conversion gain is more than OdB over 4-42GHz output frequency.