| 摘要 |
PURPOSE:To obtain the antenna for automobile mounting with excellent characteristics to the frequency of broad band, by changing the length of antenna element to the frequency to be received and keeping the standing wave ratio to the length at excellent small value at all times. CONSTITUTION:The signal from the antenna element 1 driven with motor is fed to the receiver 3 or standing wave ratio detection section 4 with the switch means 2, and the FM control oscillator 5 having the tuning knob is connected to the DC power supply 7 with other switching means 6 in interlocking with the switching means 2 to make it operative. Next, the waves in a given frequency oscillated at the oscillation section 5 is fed to the element 1 and matched at the detection section 4, and the element 5 is moved up and down or fixed with the control section 8 by using the signal from it. With this constitution, to move the element 1 up and down, it is inserted in the antenna containing tube 12, and the drive cord tied with the pole at the tip through the inside of the element 1 is operated with the rotary drum 9 and the length is adjusted with cooperation with the spring 21. |
