Antenna Design Based On Corrugated Substrate Integrated Waveguide

Modern wireless communications mainly rely on high-performance and multi-functional antenna systems.The concept of substrate integrated waveguide(SIW)has produced a historic progress in the integration of planar structures,which is more in line with the development needs of future antenna systems.SIW structures have received extensive attention due to their unique structural advantages and electromagnetic properties,but the presence of metallized vias increases fabrication cost and difficulty,making antenna structures difficult to integrate with active devices.In recent years,scholars have devoted themselves to exploring the improved structure of SIW,and the proposal of the corrugated substrate integrated waveguide(CSIW)structure is to eliminate the drawbacks brought by the perforated structure.CSIW uses open quarter-wavelength stubs instead of metal vias,which simplifies the processing process and has similar overall transmission characteristics to SIW.This paper mainly focuses on the CSIW structure.After research and discussion,three antennas are designed.The main results are as follows:1.A bent CSIW-based H-plane horn antenna is proposed.The design theory and structure of the conventional SIW horn antenna are analyzed,and the antenna size and phase correction are improved respectively.Etching rectangular slots at the aperture and loading the metal via array to achieve radiation improvement,optimize the phase distribution of the horn aperture.At the same time,the bent stubs keep the size of the flat horn unchanged.The antenna has a low profile and small physical size,is fed with microstrip port,improving inside the horn to achieve good impedance matching between the horn antenna and free space.2.A beam scanning leaky wave antenna based on CSIW structure is proposed,which has reconfigurable properties.The basic antenna structure realizes leaky waves by etching a rectangular slot array on the surface,and has good impedance matching during scanning.Then,the equivalent circuit model of the unit structure is analyzed,a set of capacitors and diodes are loaded on each rectangular slot to optimize the antenna,and a reconfigurable unit is created by controlling the cutoff or conduction of the diode.The ESC control network of the antenna is simple,the beam scanning is realized at a fixed frequency point by adjusting the DC bias voltage,the antenna gain is stable,and the scanning range is wide.3.A frequency reconfigurable antenna based on CSIW is proposed.The antenna is coupled and fed by microstrip lines.The electrical length of the stub of the CSIW structure is a quarter wavelength at the cut-off frequency.The PIN is loaded on the comb-shaped open stub on both sides of the antenna,and the electrical length of the stub is changed by controlling the state configuration of the diode,so that the resonant frequency changes.Under the four state configurations,the antenna frequency can be adjusted in a large range,and the gain and pattern of the antenna are basically the same in different configurations.The overall size of the antenna is small,and it is easy to be applied in micro communication systems.