A Reconfigurable ARBW Antenna with Stable Working Frequency

A reconfigurable axial ratio beam width (ARBW) antenna with stable working frequency is presented in this paper. The ARBW of the circularly polarized (CP) antenna can be successively adjusted by changing varactor diode. First of all, a novel structure, including four T-shaped patches and a square loop patch, is distributed around rather than connected the crossed dipole so as to keep a stable resonant frequency when changing the T shaped parasitic stub. Next, the length of the T shaped stub integrated two varactor diodes can affect the radiation field of the antenna, and further affect the ARBW of the proposed antenna. Therefore, the coverage area of the CP signal is adjusted flexibly. The result displayed that the ARBW of the proposed antenna is changed from 84° (-46°, 38°) to 157° (-67°, 90°) in XZ plane with stable resonant frequency.