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US 5,177,453 AGranted
Gain control amplifier
AssigneeRaytheon Company
InventorsMark E. Russell, John F. Mara, Jr., Michael C. Tipton
Life of this patent
Estimating the term…
Abstract
A gain control amplifier is shown to include a temperature compensation circuit and a feed forward gain control loop. With such an arrangement, a gain control amplifier is provided wherein variations of an output signal of the amplifier are minimized due to changing characteristics of the amplifier caused by ambient temperature variation or from a varying input signal level.
Claims11
A control circuit comprising:
- (a) means, having an input port, an output port and a control port and responsive to a control signal fed to the control port, for attenuating an input signal fed to the input port and for providing an attenuated signal at the output thereof;
- (b) means for providing an intermediate control signal in response to variation of signal level in the input signal, wherein the means for providing an intermediate control signal comprises:
- (i) a detector circuit having an input and an output and including a Schottky diode detector;
- and
- (ii) means for coupling a portion of the input signal fed to the input port of the attenuating means to the input of the detector circuit;
- (c) means for providing a reference signal, the reference signal indicative of ambient temperature of the circuit;
- and
- (d) means, fed by the intermediate control signal and the reference signal, for providing the control signal to the control port of the attenuating means for reducing variation of signal level of the attenuated signal.
5 more elements
A circuit comprising:
- (a) a variable attenuator having an input port, an output port and a control port to attenuate an input signal fed to the input port and to provide an attenuated signal at the output port;
- (b) a temperature transducer having a first terminal and a second terminal;
- (c) a first resistor having a first terminal and a second terminal, the first terminal of the first resistor connected to the first terminal of the temperature transducer and the second terminal of the first resistor connected to the second terminal of the temperature transducer;
- and
- (d) a second resistor having a first terminal and a second terminal, the first terminal of the second resistor connected to the second terminal of the temperature transducer and the second terminal of the first resistor to provide a reference signal thereat;
- and
- (e) an operational amplifier having a first and second input and an output, the first input of the operational amplifier fed by the reference signal and the output of the operational amplifier coupled to the control port of the variable attenuator.
4 more elements
An amplifier circuit comprising:
- (a) a first amplifier having an input and an output;
- (b) an attenuator, having an input port, an output port and a control port, the input port fed by the output of the first amplifier;
- (c) a detector circuit having an input and an output and including a Schottky diode detector;
- and means for coupling a portion of a signal fed to the input port of the attenuator to the input of the detector circuit;
- (d) means for providing a reference signal, the reference signal indicative of ambient temperature of the amplifier circuit;
- and
- (e) means, fed by the reference signal and the output of the detector circuit, for providing a control signal to the control port for reducing variations of signal level in an output signal at the output port of the attenuator.
4 more elements
A circuit comprising:
- (a) a variable attenuator having an input port, an output port and a control port;
- (b) a temperature transducer having a first terminal and a second terminal;
- (c) a first resistor having a first terminal and a second terminal, the first terminal of the first resistor connected to the first terminal of the temperature transducer and the second terminal of the first resistor connected to the second terminal of the temperature transducer;
- (d) a second resistor having a first terminal and a second terminal, the first terminal of the second resistor connected to the second terminal of the temperature transducer and the second terminal of the first resistor;
- and
- (e) an operational amplifier having an input coupled to the second terminal of the temperature transducer and an output coupled to the control port of the variable attentuator.
3 more elements
Dependencies are inferred from the claim text.