| 摘要 |
PURPOSE:To provide a double wave shared antenna for car telephone which has a simplee and inexpensive structure and can transmit and receive both 1st radio wave of 1.5GHz and 2nd radio wave of 0.9GHz. with high efficiency. CONSTITUTION:The wavelength of a 1st radio wave of 1.5GHz is set at lambdaA so that an in-phase current of both frequency bands including the 1st radio wave and a 2nd frequency of 0.9GHz is put on two radiation elements 11 and 12 (21 and 22). Under such conditions, a single antenna element 10 (20) sets the effective radiation lengths of both radiation elements at (1/2)lambdaA-(5/8)lambdaA and the electric length of a phase coil 13 (23) placed between both radiation elements at (3/2)lambdaA-(5/4)lambdaA respectively. |
