| 摘要 |
PROBLEM TO BE SOLVED: To provide a planar antenna which can widen a communicable range.SOLUTION: A planar antenna 1 has: a conductor 12 which forms a microstrip antenna together with a ground electrode 11; a plurality of resonators (13-1 to 13-n) which are arranged to perform electromagnetic coupling with the conductor 12 at prescribed intervals along a longitudinal direction of the conductor 12; switches (14-1, 14-2) provided every prescribed number of sets of two adjacent resonators. The resonator (13-1) nearest an end of the conductor 12 which is open or grounded is arranged in the way that it crosses a node nearest the other end other than the same other end among nodes of stationary waves of current flowing the microstrip antenna. With respect to the respective sets of the prescribed number of resonators, the conductor 12 has at least two partial conductors (12c, 12d) different in length from each other that are arranged in parallel between the two resonators. The respective switches (14-1, 14-2) connect any one of the partial conductors to another part of the conductor.SELECTED DRAWING: Figure 1 |
