| 摘要 |
PURPOSE: A dual band antenna is provided to allow for ease of manufacture and achieve improved efficiency of antenna by reducing degradation of performance caused due to the variation of processing. CONSTITUTION: A dual band antenna(1) comprises a parasitic element(3) arranged in the inner space of a spiral antenna(2) which is taken up at a predetermined pitch, so as to induce an impedance change from a coupling, resulting in a dual resonance. The resonance frequency is controlled by the thickness, length and shape of the parasitic element. |
