| 摘要 |
An asymmetric antenna member, or an antenna array 110 or a wireless tag reader including such an antenna member, comprises: a plurality of patch antenna elements 310, 312 disposed on one or more substrate layers, wherein a first end 306 of the antenna member is wider than a second (opposite) end 304 of the said member and a first patch antenna 310 is located at the first end 306 of the antenna member which is larger than that of a second patch antenna 312 which is located at the second end 304 of the said antenna member and where the said antenna elements have approximately the same resonant frequency. The antenna members may be distributed in a circumferential manner around an axis 320 on the outer surface of a pyramid or truncated cone formation. The first antenna element 310 may be arranged above a dielectric layer, possibly air, with a different dielectric constant to that under the second antenna element312. The antenna elements 310, 312 may be configured for horizontal, vertical or circular polarisation. The antenna array 110 may be used for selective beamforming RFID reader operations. The antenna arrangement may include an impedance matching circuit. Also disclosed is a symmetric antenna member and array. |
