Directivity Characteristics of an Ultrawideband Hybrid Offset Antenna in the 1–4 GHz Frequency Range

The paper presents the results of numerical simulation of an offset hybrid antenna in the 1-4 GHz frequency band. A four-element array of ultrawideband combined antennas with linear polarization optimized for excitation by bipolar voltage pulses of 0.5 ns duration is used as the feed of an offset parabolic reflector. The antenna is designed for a high-power source of ultrawideband radiation. The pattern functions for two modes are studied numerically in the specified frequency range. In the first mode, wave beams with linear polarization are formed, when the equally oriented elements of the antenna array are excited alternately or synchronously. The possibility to control the direction of the maximum radiation in two mutually perpendicular directions within the width of the pattern is demonstrated. In the second mode, a pair of coaxial elements is oriented orthogonally to another pair of antenna elements. This allows forming wave beams with mutually orthogonal linear polarizations at alternating excitation and a wave beam with elliptical polarization of the field at excitation with a minor time delay.