A Novel 1.05 GHz to 1.25 GHz Filtering Antenna Feeding Network With Reconfigurable Frequency and Polarization
Wei Sun, Shuxuan Liu, Xu Zhu, Xilin Zhang, Pei‐Ling Chi, Tao Yang
Abstract
In this article, a novel 1.05–1.25 GHz filtering antenna feeding network with reconfigurable frequency and polarization is proposed. It simply consists of a reconfigurable in-/out-of-phase filtering power divider and a 90° hybrid coupler. By controlling the varactors in the in-/out-of-phase reconfigurable filtering power divider (RFPD) without any switch component, the proposed three-port feeding network offers continuous reconfigurable filtering responses with four switchable output patterns including equal power dividing with phase difference of negative or positive 90° and single-ended output at either output port. With this proposed feeding network connecting to a regular dual-polarized antenna, the resulted antenna system can easily realize reconfigurable polarization of vertical polarization (V-LP), horizontal polarization (H-LP), LHCP, and RHCP, in addition to its reconfigurable filtering responses. A prototype using microstrip technology is designed, fabricated, and measured to demonstrate the proposed technique. Good agreement between the simulated and measured results is obtained. The measured results show that the feeding network covers a frequency range of 1.05–1.25 GHz, and the errors of phase difference and amplitude imbalance are less than 5 and 0.5 dB, respectively. The resulted antenna beams can be freely switched in four polarization states with good performance.