| 摘要 |
The invention is a device that provides a phase-tunable antenna feed network that allows beam-steering and beam-width variation with simple actuation, at low cost, and with high rf performance. The device provides a series-feed where signal pow er splitters and phase-shifters are alternately disposed in series. Each phase-shifter consists of reflection-mode phase-shifter elements that operate in conjunction with an isolation device. This avoids the critical resonance condition between periodically aligned phase-shifters over the entire tuning range, since the isolation devices can easily be matched and/or aligned with non-resonant spacing. The main feed-line interconnections have the same impedance, thereby enabling the utilization of the same phase- shifter design for the entire network. Moreover, a common driving mechanism can be used for the phase-shifters to steer the antenna beam. Splitting the array into two s ub- arrays with individual collective driving mechanism further allows beam-width variation by steering the beams of both sub-arrays in opposite directions. The device is further compatible with symmetrical series network designs that have better frequency response. The series feed network preferably uses a phase-shifter for shifting a signal propagating through a transmission lineby moving a conductive construct between an active line and a ground plane of the transmission line. The conductive construct capacitively couple s with either the active line and/or the ground plane, forming a capacitive shunt that reflects a significant part of the signal. The remaining portion of the signal is reflected at a terminated end of the transmission line, resulting in substantially no signa l loss.
|
