| 摘要 |
PURPOSE:To attain improvement of the antenna efficiency and to attain ease of handling by using a conductor plate forming a static capacitance to a radio equipment case used as a grounding body as an antenna and using an impedance stub comprising a feeding line for the tuning and matching of the antenna. CONSTITUTION:The radio equipment is built in a conductive case of a radio equipment main body 1 and a static capacitance is formed between the conductive case and a conductor plate 4 to which a grounding terminal of the radio equipment is connected. The static capacitance of the conductor plate 4 to the conductive case of the radio equipment main body 1 constitutes a so-called top loading antenna and even if the actual height of the antenna is low, the antenna efficiency is not lowered. The adjustment of the position of a branch point (point A) of feeders 6, 7 and the length from the point A to a short-circuit point (point B) of the feeder 7 means that the adjustment of the length of l1 and l2 in equivalent circuit shown in Fig. (b) and even if a feeding point impedance Zr of the conductor plate 4 takes any value, the impedance is matched to the characteristic impedance Zo of the feeder 6. |
