High Gain Monopulse Variable Inclination Continuous Transverse Stub Antenna for Satellite-Aided Vehicular Communications
Yang You, Yunlong Lu, Jun Xu, Jifu Huang
Abstract
This article presents a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$K$ </tex-math></inline-formula> -band high gain monopulse variable inclination continuous transverse stub (VICTS) antenna for satellite-aided vehicular communications. The radiating part is divided into four regions and fed by an air-filled single-layer E-plane waveguide comparator cascaded with two groups of mirror-symmetric multiple-port excited linear source generators (LSGs). Two waveguide delay lines are carefully designed to compensate the phase difference between the adjacent radiating regions in the desired frequency band. Combined with the nonuniform slow-wave structure underneath the radiating slots, excitation signal with uniform phase distribution can be obtained, and then, the sum and difference patterns can be produced by using the comparator. For verification, a prototype operating at <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$K$ </tex-math></inline-formula> -band is designed and demonstrated. The experimental results show that the reflection coefficients for the sum and difference patterns are all lower than −10 dB within the frequency range of 19–21 GHz. The gain drop of the sum pattern is less than 5.7 dB within the beam scanning range of −1° to −62° at 21 GHz, while the amplitude imbalance and null depth of difference patterns are less than 4.5 and −20.6 dB, respectively. The proposed antenna can be a potential candidate for the future Internet of Vehicles.