| 摘要 |
PURPOSE:To decrease the antenna element length only with the addition of a simple circuit by connecting a capacitor having a required capacitance between a lower end of a negative pole element and an outer conductor of a coaxial feeder leading to a feeding part in parallel with said element. CONSTITUTION:In taking the length of the line as l1<lambda/4 for example, the impedance Zs in an inductance L ( reactance jX1). In connecting a capacitance C (-jX1) to the open end of the line, the impedance Zs' viewed from thecapacitor is expressed in equation I, where omega is an angular velocity. In selecting the capacitor so as to zero the denominator (1-omega<2>LC), the Z's is infi nite, causing the line to be resonated. For example, a positive pole and a nega tive pole elements 16, 17 having a length shorter than lambda/4 are connected respec tively to a center conductor 20 and an outer conductor 21 of a coaxial feeder 19 and a capacitor 22 is connected between the lower end of the negative pole element 17 and the outer condutor 21 of the coaxial line to constitute an h-type antenna. |
