| 摘要 |
<p>A planar antenna comprises a ground plate 102 and a conductive plate 101 arranged in parallel. The conductive plate 101 has a ground terminal 104, a feed terminal 105 and means 107 - 109 of forming a further ground connection terminal arranged such that it will change the resonant frequency of the antenna. Each of the terminals is arranged at separate positions. A dielectric spacer 103 may be located between the plates 101, 102. The plates may be formed by metal deposited and etched on either surface of a dielectric substrate. The terminals may be L-shaped with the ground terminal 104 located between the other terminals with the distance between the terminals being equal to or less than one third of the circumference of the conductive plate. There may be one or more means of forming a further ground connection which may include a relay, diode or transistor switch. The antenna my be used in radio apparatus.</p> |
