| 摘要 |
A method and an arrangement for matching the antenna of a radio device in transmitting condition. The antenna impedance in the output of the power amplifier of a transmitter is adjusted by means of a pi-shaped reactive matching circuit, the component values of which can be selected from a relatively wide array of the alternatives. The component values are selected using multiple-way switches, which only are located in the transverse branches of the matching circuit. The switches are set by the control unit, input variables of which being the SWR value provided by the directional coupler, the operating band used each time and a value of the transmitting power. The matching is based on an adjusting process to be executed at regular intervals, in which process the control unit tries different combinations of the switch states and finally selects the combination, which brings the lowest SWR value.
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