Open waveguide beamforming antenna for radio frequency identification reader

摘要

An open waveguide antenna for a radio frequency identification reader includes a conductive annular waveguide concentric about an axis and configured for operation within an operating frequency band. A radiating slot is formed in at least one wall of the waveguide is also concentric about the axis. An odd-multiple of ports are electrically coupled to the annular waveguide, where the ports are equally spaced around the waveguide at a spacing between adjacent ports of one-half of a guided wavelength at a center frequency of the operating band. A second waveguide, smaller than the first, can also be incorporated. The second waveguide can have a different slot arrangement and fewer ports. The rectangular waveguides can operate in a non-transverse electromagnetic mode, and the ports can be individually driven to beamform the radiated signal of the antenna.

主权项

1. An open waveguide antenna apparatus for a radio frequency identification reader, the antenna apparatus comprising:
a conductive first annular waveguide concentric about an axis and configured for operation within an operating frequency band, featuring a guided wavelength at a center frequency of the operating frequency band; a first radiating slot formed in at least one wall of the first annular waveguide, the first radiating slot being substantially annular in shape and concentric about the axis; and an odd-multiple of first ports electrically coupled to the first annular waveguide, the first ports being equally spaced around the first annular waveguide at a spacing between adjacent ports of one-half of a guided wavelength at a center frequency of the operating frequency band.