The research objective of this thesis is to provide a better solution for signal interference and reduce the size of waveguide antenna. The background investigations of different waveguide fabrication technologies and switch control methods are detailed in the introductory part of this thesis. Several novel substrate integrated waveguide (SIW) antennas for different purpose are demonstrated in the body of the thesis. The designs are mainly divided into two kinds.
The first focuses on the switch beam SIW antennas working at 2.4 GHz frequency band. Compared to the corresponding waveguide antennas of multiple-input and multiple-output (MIMO), phased array and switch beam, the proposed SIW antennas have advantages in compact size, easy fabrication and high gain. By DC biasing the surface mounted PIN diodes, the waveguide slots radiate at diode-off state of reverse bias, and are shielded at diode-on state of forward bias. Based on different requirement, the SIW antennas can achieve two-direction, four-direction and six-direction transmission. The gain can be easily changed by extending the size of reflector walls.
The second focuses on reducing the volume of SIW antennas, working at 5 GHz frequency band. A new folded SIW antenna is introduced. By folded the antenna front end part to second layer, the SIW antenna reduces the total length by the size of one-quarter guided wavelength. This folded antenna can radiate either monopole mode or dipole mode, based on the metal surface area. Another two new SIW antennas reduce the total length by directly cutting the front-end part at the slot center. By utilized the intrinsic coupling radiation, the SIW antennas use two half-length slots at different broad-wall plane to achieve 360 degree propagation and wide-band end-fire radiation
