| 摘要 |
PURPOSE:To design the titled antenna in such a way that it shows nearly the same performance to two frequencies with simple constitution by winding a conductor wire nearly lambda2/4 long to the tip of an antenna element lambda1/2 long around the element in a coil so as to connect the tip of the element to the upper end of the coil. CONSTITUTION:A cylindrical insulator 2 is provided additionally to the outer circumference of the tip of the antenna element 1 lambda1/2 long, the conductor wire lambda2/4 long is wound to the outer circumference to form a coil 3 and the tip of the element 1 and the upper end of the coil 3 are connected, where the relation of lambda1<lambda2 exists. Moreover, a matching circuit 4 is arranged to the other end of the element 1 to realize the matching between the electromagnetic wave impedance at the lower end of the element 1 and the input/output terminal impedance of the device to be connected. Thus, a resonance point is given respectively to two optional frequencies without complicating the constitution. |
