High-gain planar TEM horn antenna fed by balanced microstrip line

A printed TEM horn antenna with high gain fed by balanced microstrip line is proposed. The radiation part of the antenna consists of two symmetrical triangular metal slice branches printed on the FR-4 substrate with 1.5mm thickness. The two branches are fed by balanced microstrip line. The antenna is simulated by software CST MICROWAVE STUDIO^® and the equivalent adopted dipole model is proposed to describe the radiation characteristic of the antenna. The simulated results indicate that the frequency range is from 1.64GHz to 5GHz with reflection coefficient less than -6dB, and the typical gain value is 8dB in the operating bandwidth. In order to improve antenna gain without influencing the bandwidth, the length of the dielectric slab should be extended appropriately in the main radiation direction. By extending the length of the dielectric slab appropriately in the main radiation direction, the antenna gain can be improved significantly without influence on the bandwidth. The prototype has been fabricated and measured in microwave anechoic chamber which is coincident with the simulated results. This antenna can be widely applied in the UWB field.