| 摘要 |
PURPOSE:To obtain a circular microstrip antenna resonant to mutually different frequencies by providing a larger and smaller radius parts on the cocentrical circles of circular radiant conductive elements, and providing feeding points on the larger radius and the smaller radius. CONSTITUTION:The title microstrip antenna is composed by providing a dielec tric substrate 1, a radiant conductive element 2, a ground conductor 3, a feeding point 4, and a ground piece 5. In such a constitution, the radiant conductive element 2 is formed so as to draw two cocentric circles at the radiuses a1 and a2 (a1>a2) around the ground piece 5, and so as to be circular parts at the radius a1 for the central angle parts 0-90 deg. and 180-270 deg. and at the radius a2 for the central angle parts 90-180 deg. and 270-360 deg. by setting an (X) axis direction at 0 deg.. The feeding points 4 is formed so as to be excited in the two directions at 45 deg. and 135 deg.. The radiant conductive element 2 and the ground conductor 3 are short-circuited by the ground piece 5, and the excitation in the mode other than the prescribed one is suppressed. |
