Instantaneous Bandwidth Enhancement for Variable Inclination Continuous Transverse Stub Antenna

Abstract

In this paper, a method was developed to achieve the instantaneous bandwidth enhancement of a variable inclination continuous transverse stub (VICTS) antenna. The aperture of the VICTS antenna was divided into a subarray, and the true-time delay was introduced to reduce the dispersion of the antenna. The method has low loss and is suitable for the entire beam scanning range. To demonstrate this method, a proposed VICTS antenna composed of 2 × 2 subarrays was designed and simulated. Compared with the traditional VICTS antenna of the same aperture size, the gain loss was reduced by at least 52% and the 3/4-dB gain-loss bandwidth increased from 2.5% to 4.2%. The impedance bandwidth of 16.7% with the S 11 value of each subarray below −15 dB was achieved, and the sidelobe of the whole antenna was below −10 dB. The antenna radius was 0.34 m, and the aperture efficiency was 14.8%. The proposed antenna is a suitable candidate as a gateway station antenna for low earth orbit (LEO) satellite communication.

On time-delay power divider

“…For active phased array, the time delay chips is used which is lossy and expensive. For passive phased array, such as VICTS antenna, fixed time delay can be adopted [4].…”