Study Of H-plane Horn Antenna And Frequency Reconfigurable Cavity Backed Slot Antenna Based On Substrate Integrated Waveguides

As a novel guide wave structure,substrate integrated waveguide（SIW）combines the advantages of rectangular waveguide and microstrip line,such as low loss,high Q,low profile and low cost.Also,SIW has the potential to integrate passive components and active elements on the same substrate to realize system miniaturization.SIW provides a new way for manufacturing of some microwave device.As an important part of modern wireless communication systems,antennas are boomingly developing towards miniaturization,high performance and high integration density.In addition,as a research hotspot,reconfigurable antennas could reconstruct the characteristics of antennas according to the environment and help ease the congested spectrum.This paper reviews the basic knowledge of SIW and antennas.After that,two antennas based on SIW are designed.The first one is a low-profile H-plane SIW horn antenna.To overcome the common problem of poor matching existing in SIW horn,an integrated solution which contains modified flare walls and an arc-shaped grated transition is thus introduced.The experimental results show that the proposed design can achieve an enhanced bandwidth of 25.5%with a substrate thickness smaller than 0.1λ₀ at the center frequency.The second one is a frequency reconfigurable SIW cavity backed slot antenna.This antenna is fed by grounded coplanar waveguide（GCPW）structure and six p-i-n diode switches are inserted across the slot at varying distances.The effective length of the radiating slot is controlled by the switch configuration of p-i-n diodes.The experimental results show that the adjustable frequency range extends from 4.85 GHz to5.88 GHz and the radiation pattern of the antenna changes little in tunings.