| 摘要 |
PURPOSE:To ensure a common use of a piece of antenna for several waves having different wavelengths, by installing the circuit that gives an infinite impedance to the wave corresponding to each energizing point between a pole, a specified number of branch lines' energizing points and the ground. CONSTITUTION:The height of the pole H of the 2-wave shared antenna that is used in common by two waves having the wavelengths lambda1 and lambda2(lambda1>lambda2) is set lower than lambda2/2, and the basement A1 is insulated from the ground. A feeding lead wire insulated from the ground with an insulator I at its lower end A2 is stretched out between the top of the pole H and the ground and outside the branch line containing no insulator inserted. The circuits Q1 2 and Q2 1 are installed between the basement A1, the lower end A2 and the ground. Then the impedance across each of these circuits is set to be infinite for the circuits Q1 2 and Q2 1 to the wavelengths lambda1 and lambda2 and to be zero to other waves. As a result, the waves of lambda1 and lambda2 delivered from the transmitters T1 and T2 are put into the natenna without being absorbed. Thus the antenna has an energizing action with the two waves of lambda1 and lambda2 without any mutual interference. |
