Substrate Integrated Gap Waveguide (SIGW) Antenna For The Millimeter-wave Application

Substrate integrated gap waveguide?SIGW?is a kind of novel multi-layer closed quasi-TEM mode transmission line.It realized by printed circuit board?PCB?technology and package a microstrip line in an electromagnetic bandgap?EBG?consisting of a perfect electrical conductor?PEC?and an artificial magnetic conductor?PMC?.the microstrip line guide a quasi-TEM mode electromagnetic waves propagate within SIGW.The SIGW circuit and the antenna have good electromagnetic shielding properties and convenient integration,and have much more application potential than conventional microstrip line in the design of millimeter wave circuits and antennas.This article carries out research based on SIGW technology.The main research work and conclusions are as follows:1)The working principle and design method of SIGW have been studied.Firstly,we review the development and evolution of the gap waveguide?GW?technology;then we discussed the basic working principle of ridge-type and microstrip SIGW;finally,a design example is given to demonstrate the design procedure of SIGW and the selection rule of some important performance parameters.2)A SIGW circularly polarized slot antenna is proposed.The antenna produces circularly polarized radiation by directly etching a slanted rectangular slot on the PEC layer of the SIGW,and using the microstrip line inside the SIGW to excite the slot.The working principle of the antenna is explained,based on the viewpoint of resonance mode and equivalent circuit,and then the selection method of the slot inclination angle and slot length-width ratio are proposed to help antenna design.Finally,the antenna was fabricated and tested for verification.A 23%relative impedance bandwidth(|S₁₁|?-10dB),5.3%relative axial ratio bandwidth?AR?3dB?and 6dBi peak gain can be obtained.3)A low profile embedded SIGW magneto-electric dipole antenna is proposed.The antenna employed SIGW as the feed structure and etched a square aperture on its PEC layer.magneto-electric dipoles composed of metal patches and vias are placed in the center of the aperture.This structure makes the entire antenna profile only 0.19?g??g is the waveguide wavelength?.Moreover,the working principle of the antenna and the effects regarding to the periodic structure underneath the antenna are analyzed;meanwhile,some structure parameters change influencing antenna performance are discussed.The test results show that the antenna has a relative bandwidth of 29%and an average gain of 8 dBi,a similar radiation pattern in E-and H-plane can be obtained as well.