Study Of Nonlinear Monolithic Microwave Integrated Circuits And Novel Planar Microwave Passive Circuits

This dissertation overall views the history, the state of arts and the future trend of monolithic microwave integrated circuit (MMIC). The process and equivalent circuit of MMIC passive components including resistors, capacitors and inductors are introduced. The introduction of active components is focused on nonlinear model. Three different working regions of pHEMT are analyzed biased by the drain-to-source voltage.According to the nonlinear model, a resistive pHEMT mixer is designed working in the linear region. As there is no DC voltage between drain and sorce, channel reisitor is similar to a voltage controlled resistor. Principle of the resistive pHEMT is presented. Advantages and disadvantages of different topologies are listed for comparison. A 26GHz⁴0GHz single balanced resistive mixer is designed with 90°power divider using Lange couplers. This topolopy can decrease LO leakage and improve reflection coefficient. The 90°single balanced mixer could only be used as down-converter. An IF Balun is needed for up-converter operation. A 6GHz¹8GHz double balanced resistive mixer is designed and measured. This MMIC includes three passive Baluns using spiral Marchand structure. The transmission matrix of Marchand Balun is presented for MMIC application. A novel three-coupled-lines spiral microstrip Marchand Balun is implemented on MMIC.Structure and design of microwave power transistors are introduced. The principle of class A power amplifer is analized. A 32GHz³6GHz monolithic millimeter power amplifier is designed using nonlinear model and harmonic balance simulation based on 0.25um GaAs pHEMT process. The four stages power amplifier is using tree type network for power combination. Four paralleled transistors are matched with load-pull impedance at the last stage for maxium output power. Small signal gain and large signal output power are separately measured using vector network analyzer and DC pulse.Characteristic and principle of compact microstrip resonant cell (CMRC) are presented. Three types of CMRC are compared with stop-band and slow-wave characteristic. The distributed equivalent circuit of spiral CMRC is proposed. The odd-even mode is analyzed according to the equivalent circuit and applied for circuit design. The open stubs and the capacitive loading microstrips are applied to enlarge the stop-band, decrease the insertion loss in the lowpass-band and improve the slow-wave factor of CMRC. The period structures of CMRC are implemented based on the theory of photonic bandgap.The improved CMRCs are applied to conventional microstrip circuits to achieve better performance. A frequency selective microstrip line is proposed using open stub compensated spiral CMRC. The capacitive loading CMRCs are used as feeding lines for band-pass filter to suppress spur signals. A compact wide stop-band lowpass filter is proposed with five spiral CMRC structure. A compact Wilkinson power divider with open stub compensated spiral CMRC could reject 2^nd and 3^nd harmonics. A rat-race coupler and a branch-line coupler both use spiral CMRC not only for harmonic suppression, but also for the reduction of circuit areas.