Microwave, Millimeter-wave Mixer

Mixer is usually used in communications, radar, radio astronomy, spectroscopy and so on. This thesis introduces the development and future trend of microwave and millimeter mixers, then discusses several kinds of mixers. In this thesis, the large and small signal analytical method is discussed in detail. Based on the theory and the practical needs of some projects, the thesis mainly focuses on analyzing three different kinds of mixers: the UWB mixer, the Ka band mixer and the submillimeter mixer.In the design of the ultra-wideband (UWB) mixer, the nonlinear transmission line (NLTL) is used. Base on the theory analysis and computer simulation of the NLTL, the UWB mixer is designed by using the low-pass and broadband characteristics of the NLTL. Distributed filtering by periodic loading of the NLTL with resonant circuits is proposed to reject the unwanted signals.Based on the traditional harmonic mixer, a wide-band harmonic mixer is proposed by using ring circuit and the structure of balun. A harmonic mixer covering the entire Ka-band broadband is designed.Until now, few research achievements on submillimeter mixer are reported in China. In this thesis a submillimeter mixer including waveguide-to-microstrip transition, low pass filter and bias circuit is designed in detail. It can reach the level of domestic processing technology.As the important component of receiver system, mixer has an obvious role. Its prospect and application are widespread applied in civilian or military region. This assignment design of mixers may be a practical reference for study and development in future.