Millimeter-wave Transceiver Front-end Development

In millimeter-wave solid-state systems, the millimeter-wave transceiver front-ends play critical roles in the whole system. With the rapid development of the modern communication and radar systems, millimeter-wave transceiver front-ends are developing toward smaller, lightweight, solid-state and high-reliability direction. This thesis is focused on the research of millimeter-wave transceiver front-ends. Base on carefully scheme comparison and the existing experiment facilities in our laboratory, the hybrid millimeter-wave integrated circuits are chosen for the final system design. In the passive circuits design of the system, the stepped impedence microstrip lowpass filter, millimeter-wave bandpass filter and E-plane waveguide-microstrip transition are designed. In the active circuits design of the system, MMIC chips are used for improving the performance of the system. This thesis is focused on the fourth subharmonic mixer design. In the millimeter-wave band, it is very difficult and expensive to get the millimeter-wave LO sources. In this thesis we use the subharmonic mixer with an antiparallel diode pair topology to solve this problem. The mixer and the filter are fabricated on the thin film ceramic substrate. The test results indicated that the conversion loss of the fourth subharmonic mixer is less than 15dB in the frequency range of 34.5GHz-35.8GHz, and 11.3dB at the center frequency of 34.68GHz. Finally, we test the whole millimeter-wave transceiver front-end, and the test results demonstrate that: the receiving gain is 20.34dB at the center frequency of 34.68GHz; on the other hand, the transmitting gain can achieve 8.31dB at the center frequency of 34.68GHz. Although there is still certain gap between the measured transmitting gain and the anticipated performance, this problem can be solved by optimizing the passive circuits of the system or adding more amplifiers. The basic operating principle of the filter, the fourth subharmonic mixer and the E-plane waveguide-microstrip transition has also been presented. The transceiver system is designed, simulated and optimized using circuit simulating software of ADS (Advanced Design System) and high frequency field simulating software of Ansoft HFSS, the designed and measured results have good consistency. It has shown the effectiveness of design method in this thesis.