| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a helical antenna for a portable radio equipment provided with separated two communication bands or a wide communication band by one communication band changeover switch 1. SOLUTION: This antenna is provided with a radiation element in a helical shape provided with one power feeding terminal 2 and two communication band changeover terminals 3 and 4, a switch 5 for short-circuiting or opening the two communication band changeover terminals and a switch driving circuit 8 for driving the switch. Corresponding to signal impression from the outside, the switch driving circuit short-circuits or opens the switch, the two communication band changeover terminals are opened or short-circuited and thus, a resonance frequency is switched.</p> |
