Voltage-controlled Oscillator Based On Substrate Integrated Waveguide Technology Research

Frequency sources are the heart of communication and electronic systems, and they play an important role in the whole systems. In microwave and millimeter-wave bands, the frequency sources are widely used as the local oscillators (LO) in the satellites, radars and wireless base stations. As the crucial part of the frequency source, the oscillator always is one of the focuses of microwave research. Recent years, based on the proposed new microwave techniques and processes, such as the substrate integrated waveguide (SIW) and the low temperature co-fired ceramic (LTCC), the microwave oscillator has become a research direction with good application prospect.Firstly, based on the basic theories of microwave oscillators, three kinds of circuit structure, including series feedback, parallel feedback and push-push, are analyzed in turn. Also, the theory of phase noise is analyzed.And then, the theories and design methods of SIW technology are introduced and analyzed. Afterwards, according to the corresponding theories, the research on the SIW oscillators is carried on.At first, by applying the SIW resonator to the design of traditional series feedback oscillator, a C-band SIW voltage-controlled oscillator (VCO) is designed. Then, in order to improve the limited available frequency of transistor, a Ku-band SIW push-push VCO is designed on the basis of above C-band oscillator design. Taking account of the situation that the fundamental frequency suppression and the isolation of two fundamental frequency oscillators can’t satisfy the need of actual use generally, a SIW power combiner is applied firstly to the design of SIW push-push oscillator and traditional push-push dielectric resonator oscillator (DRO) respectively. As the measured results shown, the push-push oscillator using the SIW power combiner can improve the suppression of fundamental frequency component obviously, and the measured value can achieve about30dBc. Furthermore, the simulation accuracy of push-push oscillator can also be improved, due to the enhancement of isolation between two fundamental frequency oscillators.In this thesis, many kinds of electromagnetic simulator are used in the design of oscillator. Then, by fusion of the SIW technology and the design method of traditional microwave oscillator, a set of design simulation and test method of SIW push-push VCO is summarized. As the measured and tested results shown, the proposed design method is available.