NOTCH ANTENNA

摘要

A notch antenna 10, a notch antenna plate 20, a method of making a notch antenna or a method of installing a notch antenna comprise a conductive plate 20 with a first notch 21 coupled to a feed line 30 and a second notch 22 passively excited by a signal supplied to the first notch 21. The second notch 22 may be provided with an adjustment portion to change the effective length of the second notch in response to a detected frequency shift from a desired centre frequency caused by the electrical permittivity of the installation position. The adjustment portion may be a conductive element such as an adhesive backed metallic tape, a switch or a PIN diode coupled across the notch 22. The conductive plate 20 maybe formed from an elastically deformable or flexible material. A vehicle registration plate may form part of the cover for the notch antenna 10. The notch antenna 10 may provide a compact, efficient and easy to adjust antenna.