| 摘要 |
PROBLEM TO BE SOLVED: To improve IM (intermodulation) by forming the 1st gain adjustment signal according to input and output characteristics changed continuously or stepwise monotonously when the received signal strength is within a prescribed range. SOLUTION: A received signal electric field strength RSSIIN outputted from a multiplier circuit is given to 1st and 2nd level conversion circuits 41, 43 and given to 1st and 2nd level conversion characteristic changeover threshold levels RSSITH1, RSSITH2. The 1st level conversion circuit 41 and a D/A converter 42 generate a gain adjustment signal RX AGC ADJ given to a power control amplifier (AGC AMP) and the 2nd level conversion circuit 43 and a D/A converter 44 generate a gain adjustment signal LNA GAIN ADJ given to a low noise amplifier (LNBA). When the reception signal intensity is within a prescribed range, the 1st gain adjustment signal is generated according to the input and output characteristics changed continuously or stepwise monotonously. |
