| 摘要 |
PURPOSE:To ensure a common use of a piece of antenna for several waves having different wavelengths, by providing the circuit that gives an infinite impedance to the waves corresponding to each energizing point between the exciting point of a specified number of branch lines and a pole and the ground. CONSTITUTION:The height of the pole H of the 2-wave shared antenna that is used in common by two different types of waves having the wavelengths lambda1 and (lambda2>lambda2) is set lower than lambda2/2, and the basement A1 is insulated with an insulator BI. The branch lines G1'-G1''' are stretched out between the top of the pole H and the ground, and the lower end A2 of the line G1'' is insulated from the ground by an insulator I. Then the circuits G1 2 and Q2 1 are installed between the basement A1 and the lower end A2 and the ground. The impedances across these circuits are set to be infinite for the circuits Q1 2 and Q2 1 to the waves of wavelengths lambda1 and lambda2 respectively and to be zero to the waves of other wavelengths. As a result, the waves of wavelengths lambda1 and lambda2 delivered from the transmitters T1 and T2 are put into the antenna without being absorbed. Thus the antenna has an energizing action with two waves of lambda1 and lambda2 without any mutual interference. |
