A dual-polarized cavity-backed Vivaldi antenna with simple feeding structure for telemetry system application

Abstract

ABSTRACT This paper proposes a dual-polarized cavity-backed Vivaldi antenna with wide bandwidth for telemetry system. The designed dual-polarized antenna is composed of two orthogonal printed dipole antennas, and each polarized antenna is fed by Non-Coplanar Strip line. A wideband Balance to Un-balance transformer (Balun) is employed to connect the input microstrip transmission line with the antenna Vivaldi radiator. The designed feeding structure makes the two antenna substrates to be directly mounted and the occlusion problem is resolved, and the port isolation is also improved. A cylindrical metal cavity is introduced to enhance the radiation pattern and efficiency. The dual-polarized antenna can be operated in the frequency band of 1.9–2.5 GHz, which covers the band frequencies of the designed telemetry system. The simulated results through the full-wave electromagnetic simulation technique show that the gains of two polarization ports are higher than 6.9 dBi at central frequency. A prototype with dual linear polarization has been fabricated for validation. Both the simulation and measured results show that the proposed antenna has a bandwidth of 27% when the voltage standing wave ratio is less than 2 with desirable directional radiation patterns as well as high isolation better than −25 dB between the two input ports. The antenna scheme proposed in this paper is suitable for the telemetry system application.