| 摘要 |
An antenna comprises a linear antenna element 10 with one end connected to a feed 15 and the other end connected to at least one end of at least one arm element 20, where the other end of the or each arm 20 is open circuited and where the antenna is arranged to resonate at a higher order mode of a target frequency. The higher order mode may be an odd mode such as the third order mode of a target frequency. Alternatively, the said mode may be an even mode, such as the second order mode, where an impedance transformer is provided at the feed to the antenna. The, or each, arm element 20 may be tilted relative to the longitudinal direction of the linear antenna element 10. Various numbers of arm elements 20 may be used, for example one, four or eight arm elements 20 are disclosed. The arm elements 20 may be evenly distributed and may be of various shapes such as straight, helical or meandering. The antenna may be arranged to form a dipole antenna formation. The antenna is intended to provide a compact antenna with good gain and directional operational characteristics. |
