Patent ID: 8498600

Claim:
A tuner, comprising: a low noise amplifier (LNA) for amplifying a radio frequency (RF) signal; a first received signal strength indicator (RSSI) for detecting a received signal strength indication of the amplified RF signal and obtaining a first signal strength voltage; a mixer coupled to the LNA and for down-converting the amplified RF signal into a first intermediate frequency (IF) signal according to a local oscillation frequency; an IF filter coupled to the mixer and for filtering the first IF signal to obtain a second IF signal; a second RSSI for detecting received signal strength indication of the second IF signal and obtaining a second signal strength voltage; and an adjustment unit for adjusting a gain of the LNA according to the first signal strength voltage and the second signal strength voltage, wherein when the adjustment unit judges that the first signal strength voltage is higher than a first threshold and lower than a second threshold, the tuner enters a high-power mode, and the adjustment unit maintains or lowers the gain of the LNA according to the first signal strength voltage to cause the tuner to operate linearly.