| 摘要 |
PROBLEM TO BE SOLVED: To change the antenna characteristic impedance, etc., and to facilitate the production of a microstrip antenna by adhering a metallic film of a small size onto a part of a loop-shaped circuit to change the antenna characteristics and also providing a feeder line and a matching line. SOLUTION: An antenna element 2 consists of a metallic film which is adhered to a loop-shaped circuit on the surface of a dielectric plate 1 having small thickness compared with the radiation wavelength of the radiated electromagnetic wave. Then a small rectangular metallic plate 41 is adhered on the plate 1 including the metallic film constructing the loop-shaped antenna circuit. Thus the section shape of the loop-shaped circuit is partly changed, and the characteristic of current flowing through the changed section of the circuit is also changed. Therefore, the electrical characteristics of a microstrip antenna such as the characteristic impedance, the resonance wavelength, the directional pattern, etc., can be changed. As a result, the antenna can easily be designed and the antenna size can be reduced. |
