| 摘要 |
PROBLEM TO BE SOLVED: To provide a receiver in which useless power consumption is excluded by securing the linearity of an RSSI detection circuit output circuit. SOLUTION: The receiver for linearly demodulating a high frequency signal of an antenna input terminal 1 is provided with first switches 19 and 20 for turning on and turning off the power supply of amplifies 4 and 8, second switches 5 and 9 for passing and bypassing the signal systems of the relevant amplifiers, and an RSSI detection circuit 13. A threshold is set to RSSI detecting voltage, and when the RSSI detecting voltage is equal to or higher than the threshold, the power supply of the amplifiers 4 and 8 is turned off with the first switches 19 and 20. At the same time, the second switches are changed over to a state for bypassing the amplifiers to suppress the amplification factor of a received signal. Thus, even when an electric field is strong, the linearity of an RSSI circuit is secured. When the RSSI detecting voltage is equal to or lower than the threshold, the power supply is turned on with the first switches 19 and 20, and the second switches 5 and 9 are changed over to a state for bypassing the amplifiers. COPYRIGHT: (C)2003,JPO
|
