Substrate Integrated Waveguide Microwave And Millimeter Wave Passive Components Research

Substrate integrated waveguide is a novel guided-wave structure developed in recent years. In this thesis, the methods of designing substrate integrated waveguide passive components of microwave and millimeter-wave have been analyzed, with the equivalence of the propagation characteristics between the substrate integrated waveguide and the rectangular waveguide and the methods of analyzing the rectangular waveguide. The main results are as follows:1. Ka-band substrate integrated waveguide bandpass filter has been designed. The structure of filter is Chebyshev shunt inductance coupled waveguide filter. The filter which has high working frequency is fabricated and measured. From the measured results, Ka-band filter works at 34.7GHz, with bandwidth of 2.8GHz, insert loss of 3.5 dB and maximal return loss of -14.4 dB in the passband.2. Ka-band Y-junction substrate integrated waveguide power divider has been designed. In this structure, three metallic vias have been introduced to reduce the reflection coefficient of the input port and to avoid large reflection at 35GHz. The power divider has been fabricated and measured. From the measured results, the power divider is working from 26GHz to 40GHz, with maximal return loss of -10 dB, insert loss of two branches of 2.4 dB and 3.39 dB, ripple of 1.8 dB and 2.7 dB. The isolation between two output ports is bigger than 5 dB. The difference of the phase between two output ports fluctuates from -9°to 13.5°.3. Substrate integrated waveguide cruciform directional coupler which works from 31GHz to 39GHz have been designed. This kind of directional coupler has high working frequency, compact size (21mm*21mm)and wide bandwidth. The directional coupler is designed, fabricated and measured. From the measured results, the directional coupler has the maximal return loss of -12.5 dB, direct transmission coefficient varying from 3.2 to 4.2 dB, the isolation of 24.8 dB, coupled coefficient varying from 3.6 to 8 dB, the difference of the phase between the output port and the couple port varying from 97°to 130° In a word, substrate integrated waveguide filter, power divider and directional coupler have been studied in this thesis. These technologies are studied in detail and successfully applied, which might be helpful to further application of substrate integrated waveguide passive components design.