| 摘要 |
<p>An apparatus and method compensates for an antenna impedance mismatch using a pre-determined indicator, which can be a below-threshold signal-to-noise ratio (SNR) in conjunction with a below-threshold SNR rate of change and an above-threshold rate of SNR decrease, comprises a mismatch detection module and an antenna tuning module. A below-threshold received signal strength indication (RSSI), or an above-threshold RSSI in conjunction with a below-threshold SNR, can also be a mismatch indicator. In the event of a mismatch, an antenna tuning circuit increases or decreases the frequency by a pre-determined increment S507, determines if matching is improved S508 and either continues to increase or decrease the frequency by said increment in the event of improved matching S509, or reverses the sign of the increment if matching is not improved S510. Alternatively, an apparatus 600 and method compensates for impedance mismatch of an aerial, comprising a differential amplifier 619 comparing first and second voltages derived from an antenna input and a power amplifier 620 respectively, the difference between these being proportional to impedance mismatch, and an antenna tuning module 602. A processing module and a low pass filter may also be provided.</p> |
