Research On Broadband BCSIW Structure Horn Antenna And Arra

Wideband end-fire antennas have the advantages of broadband and great directivity,which are widely used in wireless communication industry and military field,such as air-bone,vehicle-borne and missile-borne equipment.The end-fire antenna with low-profile characteristic is also a good choice for conformal antenna.The antenna is installed on the conformal carrier,which can weaken the air resistance,reduce the cost and complexity of installation,and also improve the stability in complex environments.By adjusting the direction of the beam,the multi-beam antenna can broaden the bandwidth to a certain extent,improve the signal-to-noise ratio and the utilization rate in the spectrum.Meantime,the multi-beam antenna array with small tilting angle is also an effective method to diffract reflected waves and suppress multiple reflections.The circularly polarized antenna can also reduce the effect of Faraday rotation and the multipath effect while the waves with different rotations have high isolation degree.Based on this background,some research is done about low-profile and wide bandwidth characteristics of H-plane horn antennas with the BCSIW structure.The details are as follows:1.The H-plane horn antenna based on the BCSIW structure with ultra-wideband characteristic is proposed,which is working in the frequency range of 6-18 GHz.The horn antenna is implemented in the substrate with the thickness of 3.175 mm.The metal holes in the substrate integrated waveguide(SIW)structure are replaced with bent quarter-wavelength open circuit microstrip stubs to form an electric wall.The arc-shaped aperture is employed to achieve smooth transition from horn aperture to the free space,which also improves the front-to-back ratio of the radiation pattern.2.A broadband linear array in H-plane is designed based on the H-plane horn antenna.In order to improve the radiation performance,two approaches have been taken,one is extending the dielectric slab in the semicircular form to increase the front-to-back ratio.The other is digging holes on the surface along the aperture of the antenna to perturb the field distribution and perform phase correction.The method of maximum power transfer efficiency(MMPTE)is used to calculate the excitation distribution to achieve the multi-beam.According to the above excitation distribution,a wideband butler matrix feed network is designed with the method of slot coupling to realize the multi-beam in the range of 6 GHz-18 GHz.3.A conformal circularly polarized antenna with broadband and low-profile characteristics is proposed,which is wrapped around the hollow cylindrical.The H-plane horn antenna based on the BCSIW structure provides vertical polarization waves while the Yagi antenna with the fan-shaped driving elements provides horizontal polarization waves.The transition section from the horn aperture to the Yagi provides a phase delay,which eventually radiates circularly polarized wave.The carrier of the antenna is a hollow aluminum cylinder.In order to prevent the bottom of the Yagi antenna from shorting the cylinder,the substrate with a thickness of 0.127 mm is used for isolation.Finally,the antenna has an axial ratio of less than 3 d B and a highly isolated directional pattern from the range of9.4 GHz-21.7 GHz.