The Research On W-band Receiver Front-end

The W-band receiver front-end is developed in this dissertation. The system is realized using hybrid integrated circuits because limited by the device and manufacture technique. The mission of the receiver front-end is converting the signal with frequency from 92 to 96 GHz, which received by the antenna to intermediate frequency signal with frequency from 8 to 12 GHz. The receiving sensitivity and frequency stability are important. The system consists of radio frequency band pass filter (BPF), local oscillator (LO) and sub-harmonic mixer. Finlines, finline discontinuities and the three parts as mentioned above are discussed respectively.A software which calculates the characteristic impedance and propagation constant of finline is developed. The radial basis network is used as the finline discontinuities EM neural network models. EM software anlysis is employed to characterize finline discontinuities. EM neural network models are then trained using physical parameters and frequency as inputs and equivalent electric circuit element parameters of finline discontinuities as outputs. Once trained , the EM neural network models can simulate equivalent electric circuit element parameters of finline step, notch and strip very fast and efficiently. These trained models allow for circuit design, simulation, and optimization. Circuit simulated with these models.The BPFs are realized using E-plane filter. The U band filter is designed by mode-matching method, and simulating result given by commercial simulation software achieves the aim. A method for synthesis filter with the EM ANN models, which can be used in complex structure, is given to design E-plane filter. The EM ANN model with exchange the input/output is given to simplify the process of synthesis filter. The method can obtain the actual dimension avoiding solved equations. A E-plane BPF that uses in the RF network is developed by this method, and the measured results coincide with the simulated.The local oscillator source is realized by a method, which a high stability microwave phase locked loop oscillator is achieved, then the microwave signal is converted to millimeter wave by a quad-multiplier. The microwave locked phase...