| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a technique capable of transmitting and receiving radio waves of three given kinds of frequencies Fa, Fb, and Fc by one antenna. <P>SOLUTION: When a cylindrical antenna element 4 and a helical antenna element 3 are arrayed in series and connected to a high frequency circuit 1 as shown in (A), they resonate at frequencies f<SB>0</SB>, fb, and fc as shown by the solid line in Fig. (B). When an adjusting rod 5 is inserted into the helical antenna 3, the tuning curve shown by the solid line changes to the chain line. This change varies with the diameter of the adjusting rod 5 (the ratio to the diameter of the helical antenna 3) and the insertion depth. Those factors are adjusted to move tuning points of the chain-line curve to Fa, Fb, and F. <P>COPYRIGHT: (C)2004,JPO |
