HELICAL ANTENNA APPARATUS PROVIDED WITH TWO HELICAL ANTENNA ELEMENTS, AND RADIO COMMUNICATION APPARATUS PROVIDED WITH SAME HELICAL ANTENNA APPARATUS

摘要

It can be used in a wideband, and also provides a helical antenna apparatus capable of reducing the power loss caused by the impedance mismatch at the time close to the human body. ; A variable capacity element (3) is connected between the helical antenna element 1 and the helical antenna element 2, the variable capacitance element 4 has a balanced-first unbalanced converter 6 of the unbalanced side port (port) is connected between the terminal and the helical antenna element 1, a variable capacity element (5) is balanced-is connected between the second terminal of the unbalanced-side port of the unbalanced converter 6, a helical antenna element (2) . Reflected power (反射 電力) detecting circuit 20 measures the detection voltage Vd corresponding to a transmission signal from the wireless transmitter to the reflected power is reflected when the power supply to the helical antenna elements (1, 2), adaptation control type controller (10 ) detects a control voltage Vd adaptation values ​​each with a capacity of the variable capacity element (3, 4, 5) such that a minimum.