Tunable slot antenna with capacitively coupled slot island conductor for precise impedance adjustment

摘要

A coaxial resonant slot antenna includes a flat rectangular conductive box having its top plate with a slot being defined therein, and a strip conductor disposed inside the box and electrically insulated from the box while high frequency or RF power is fed to the strip. An island conductor is provided in the slot for defining a capacitance between itself and the frame. This capacitance is rendered variable in value by use of a variable circuit.