A Unidirectional Cylindrical Conformal Monopole Antenna Designed for Impulse Radar System

A compact unidirectional cylindrical conformal monopole antenna with 40 mm diameter and 25 mm height is designed for an impulse radar system. The antenna is employed for radiating Gaussian monocycle with peak-peak width of 300 ps. Impedance loaded is adopted to achieve ultrawideband (UWB) impedance matching and unidirectional radiation. Simulations with CST Microwave Studio (CST MWS) and experiments have been conducted to assist with the characterization of the antenna. Simulation results and experimental data showed to be in good agreement. The impedance bandwidth is 0.67-2.15 GHz for
S
₁₁
≤ -10 dB and covers the main range of the pulse spectrum. The front-to-back ratio of the amplitude of the received signal reaches about 3.5:1.