| 摘要 |
<p>An apparatus 600 and method compensating for impedance mismatch of an aerial comprises an antenna mismatch detection module 601 and an antenna tuning module 602. The mismatch detection module 601 comprises a differential amplifier 619 comparing first and second voltages derived from an antenna input and a power amplifier 620 respectively. The antenna input and power amplifier 620 output are connected by an inductor 610. The voltage difference across the inductor 610 is proportional to impedance mismatch. A tuning circuit may be provided in the antenna tuning module 602, comprising a variable capacitor which can be connected to the output of the differential amplifier 619. The tuning circuit may further comprise a capacitor or an inductor connected to the terminal of the variable capacitor. A bridge circuit may be provided in the mismatch detection module 601, comprising capacitors 613, 615, 616, 618 and diodes 614, 617. A processing module and a low pass filter may also be provided between the differential amplifier 619 and the tuning circuit.</p> |
