Patent Number: 6,400,934

Title: Method for radio receiver input off-channel and on-channel overloadprotection

Abstract: A method (200) for protecting receiver circuitry from high radio frequency(RF) overload voltages input to the antenna by monitoring power level andreceived RSSI level includes detecting (209) inside the receiver anyreverse RF power on an antenna (201) connected to the receiver. Thedetected RF power is converted (211) to a direct current (DC) voltage. TheDC voltage is compared (213) against a predetermined reference voltage. Aswitch (205) is than actuated (219) to disconnect the antenna if the DCvoltage exceeds the reference voltage. Moreover, a radio signal strengthindication (RSSI) is detected (221) based upon a received on-channelsignal and is compared (223) to a first reference voltage. A secondary RFattenuator is actuated (225)if either the RSSI is lesser than the firstreference voltage (223) or greater than a second reference voltage(227)for reducing input signal strength from the antenna. Thus, if a receiveris receiving a medium-strength on-channel signal (RSSI level falls betweenthe first and second reference voltage), the secondary section of thetransmit/receive switch will not be activated to minimize the degradationof the received signal. As long as an overdrive condition exists (231),the RSSI level will be monitored. If the monitored reverse power voltage(239) falls below the predetermined reference voltage (241), the secondarysection of the transmit/receive switch will be disabled (245).

Inventors: Calixte; Joseph Andral (Miramar, FL)


International Classification: H04B 1/10 (20060101); H04B 001/16 ()

Expiration Date: 06/04/2014