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US 2010/0301948 A1Published application
Low Noise Amplifier and Mixer
AssigneeIndian Institute of Science
InventorsBharadwaj Amrutur, Kannan Aryaperumal Sankaragomathi
Life of this patent
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Abstract
A low noise amplifier (LNA) system with controllable linearity and noise figure versus power consumption is provided. The system comprises two control inputs for tuning. One input controls an effective transistor width, and the other input controls bias current. Changes to the effective transistor width alter a gain that is applied to a signal, and changes to the bias current alter a power consumption of the system. For more stringent signal specifications, an impedance matched inductive degeneration variation of the LNA is provided.
Claims20
A receiver circuit comprising:
- a plurality of amplifying transistors connected in series and for amplifying an input signal;
- a plurality of control transistors, wherein each of the plurality of control transistors is connected to one of the plurality of amplifying transistors, wherein each control transistor receives an independent control signal at a gate of the control transistor and outputs to one of the amplifying transistors so as to provide for independent operation of each of the plurality of amplifying transistors, and wherein a number of the plurality of amplifying transistors in operation corresponds to a transistor width of the receiver circuit;
- and
- a bias generation circuit including circuitry that mimics operation of the plurality of amplifying transistors and the plurality of control transistors, the bias generation circuit receiving the independent control signals and an RF reference bias current input and outputting an RF bias control voltage to the plurality of amplifying transistors, the RF bias control voltage corresponding to a value of the transistor width,
- wherein the independent control signals and the RF reference bias current input are independently tunable.
2 more elements
A method of adjusting operating characteristics of a receiver, comprising:
- receiving a radio frequency (RF) input signal;
- evaluating a signal quality of the RF input signal to determine whether the RF input signal substantially meets a noise figure and linearity requirement;
- adjusting a gain of the receiver based on the evaluation of the RF input signal, wherein adjusting the gain of the receiver includes receiving independent control signals at gates of control transistors that each output to one of a plurality of amplifying transistors within the receiver so as to provide for independent operation of each of the plurality of amplifying transistors to control the gain of the receiver, and wherein a number of the plurality of amplifying transistors in operation corresponds to a transistor width of the receiver circuit;
- adjusting a bias current based on the transistor width of the receiver circuit and independently of the independent control signals;
- amplifying the RF input signal using the adjusted gain and adjusted bias current values;
- and
- outputting the amplified RF input signal.
4 more elements
An inductively degenerated low noise signal amplifier, comprising:
- a first inductive circuit including:
- a first plurality of amplifying transistors connected in series and for amplifying an input signal;
- and
- a first plurality of control transistors, wherein each of the first plurality of control transistors is connected to one of the first plurality of amplifying transistors, wherein each first control transistor receives an independent control signal at a gate of the first control transistor and outputs to one of the first amplifying transistors so as to provide for independent operation of each of the first plurality of amplifying transistors, and wherein a number of the first plurality of amplifying transistors in operation corresponds to a transistor width of the receiver circuit;
- and
- a second inductive circuit including:
- a second plurality of amplifying transistors connected in series and receiving an output of the first plurality of amplifying transistors;
- and
- a second plurality of control transistors, wherein each of the second plurality of control transistors is connected to one of the second plurality of amplifying transistors, wherein each second control transistor receives an independent control signal at a gate of the second control transistor and outputs to one of the second amplifying transistors so as to provide for independent operation of each of the second plurality of amplifying transistors, and wherein a number of the second plurality of amplifying transistors in operation corresponds to the transistor width of the receiver circuit;
- wherein adjusting a gain of the second plurality of amplifying transistors adjusts an inductance of the first inductive circuit and the second inductive circuit.
7 more elements
Dependencies are inferred from the claim text.