Patent ID: 7773035
Filing Date: 2010-08-10
Classification: H01Q

Abstract:
1. A microstrip antenna comprising: a substrate; a feed element formed as a thin layer and disposed upon a front surface of said substrate; a parasitic element formed as a thin layer and disposed upon said front surface of said substrate and separated by a predetermined interelement spacing from said feed element; a ground electrode disposed to oppose said feed element and said parasitic element via said substrate; and a grounding means connected between said parasitic element and said ground electrode and switching said parasitic element between a grounding state and a floating state, wherein said grounding means includes a switching line, which is opened and closed, for releasing high-frequency signals from said parasitic element to ground level, wherein said grounding means has a line length T extending from a ground point provided on said parasitic element through a through hole in the substrate to said ground electrode, and wherein said line length T is set so that an amount of a high-frequency electrical flow that flows in said parasitic element becomes zero in said grounding state.