Patent ID: 6553214
Filing Date: 2003-04-22
Classification: H04B

Abstract:
An active antenna system with automatic overload protection circuitry, comprising:an antenna; a directional coupler connecting the antenna, an electronic switch and a detector; an RF low noise amplifier connected to the electronic switch via a first matching circuit; an operational amplifier having an input connected to the detector, and an output connected to a variable shunt impedance and a comparator, the operational amplifier configured to generate a control voltage when a value of an antenna signal is greater than a first reference signal, the control voltage acting to lower impedance of the variable shunt impedance, wherein a signal to the RF low noise amplifier is decreased; a bypass path including a second matching circuit, which bypasses the RF low noise amplifier, wherein the bypass path is actuated when the antenna signal is greater than a second reference signal; and, a radio connected to the RF low noise amplifier via a third matching circuit and connected to the bypass path.