Patent ID: 6026285
Filing Date: 2000-02-15
Classification: H03G,H04B

Abstract:
An intermodulation (IM) distortion reduction circuit for a radio frequency (RF) receiver having an RF input signal receiver line, said IM distortion reduction circuit comprising:a variable attenuator connected to attenuate and reduce IM distortion for RF signals on the RF input signal receiver line of the RF receiver; andan attenuation controller coupled to said variable attenuator to control attenuation by said variable attenuator responsive to RF input signal power levels,wherein said attenuation controller includes an operational amplifier, wherein said operational amplifier includes an attenuator control input coupled to a received RF signal strength indication source, a threshold level input, and an amplified comparison output coupled to an input of said variable attenuator, andwherein said attenuator controller further includes an attenuator enabler coupled to said attenuator control input, wherein said attenuator enabler includes a switch with a control input, a ground input, and an enabling output coupled to said attenuator control input.