The Research Of Oscillator Based On Substrate Integrated Waveguide Technology

Frequecy sources are important parts of modulation circuit, demodulation circuit, and PLL circuit, and now the high performance, high integration, miniaturization of the frequecy sources are the hot topic. SIW, as a new waveguide structure, has advantages of high Q of the metal waveguide, low loss, good high-frequency characteristics, power capacity and easy integration with planar microstrip circuits, providing a good solution of the design of high-performance oscillator. The paper researched reflective oscillator, feedback oscillator, voltage controlled oscillator with hexagonal, rectangular substrate integrated waveguide resonance cavity and HMSIW resonance cavity based on SIW basic theory and technology. Specific work was as following:Firstly, some basic theories and basic methods of the design of SIW oscillators were introduced in the thesis. Starting from the basic theory of substrate integrated waveguide, and then introduced many transitional forms of substrate integrated waveguide cavity and microstrip line, then analysed the basic design methods and theories of reflective oscillator and feedback oscillator in the form of mathematical deduction and introduced the important parameters of the phase noise in the form of expression describes. Because of replacing ordinary capacitors by gap capacitors, the paper introduced the basic theory of gap capacitors in the end.Secondly, the paper based on the resonant oscillation mechanism of the principle of reflection type oscillator and the resonance mechanism of hexagonal substrate integrated waveguide cavity, putted the SIW hexagonal resonance cavity as the oscillator cavity, adjustted the output frequency in method of the combination microstrip line and hexagonal substrate integrated waveguide cavity, a reflection oscillator of 10.3GHz was designed and implemented ultimately.Thirdly, the paper treatted the half mold substrate integrated waveguide narrowband filter as frequency selective network of the oscillator, based on the principle of oscillating feedback type oscillator, adjusted the coupling coefficient of the HMSIW narrowband filter by the way of opening the gap, adjusted the length of a ring network to control the frequency of the oscillator, a feedback oscillator of 9.88 GHz was designed and implemented ultimately.Finally, a voltage-controlled oscillator of 18 M based on substrate integrated waveguide technology was designed and implemented, proved the feasibility that the substrate integrated waveguide technology was applied to voltage-controlled oscillator, proved the feasibility that a varactor coupling to the rectangular SIW for adjusting frequency, proved the feasibility that the solder joint position of the varactor can change the resonance frequency of cavity.