| 摘要 |
PROBLEM TO BE SOLVED: To match mutually different plural frequency bands without changing directional characteristics. SOLUTION: A radiating element 14 is connected to the internal conductor (not shown in the figure) of coaxial feeder line 12 and at the position away from the top end of radiating element 14 for a distance L1 (≈λ1 ÷4: λ1 is the wavelength of electromagnetic wave at frequency f1 ) corresponding to the frequency f1 to be matched, four ground wires 16 are radially provided so as to be connected to the external conductor (not shown in the figure) of feeder line 12. The length of respective ground wires 14 is set so that the top end part can be positioned away from the center of feeder line 12 for the distance L1 . Besides, at the position away from the top end of radiating element 14 for a distance L2 (≈λ2 ÷4: λ2 is the wavelength of electromagnetic wave at a frequency f2 ) corresponding to the frequency f2 to be matched, four ground wires 18 are radially fitted so as to be connected to the external conductor of feeder line 12. The length of respective ground wires 18 is set so that the top end part can be positioned away from the center of feeder line 12 for the distance L2 . |
