Amplifier with dynamic bias
AssigneeQUALCOMM Incorporated
InventorsBo Sun, Sankaran Aniruddhan
Life of this patent
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Abstract
Techniques are provided for dynamically biasing an amplifier to extend the amplifier's operating range while conserving power. In an embodiment, a detector is provided to measure the amplifier output to determine an operating region of the amplifier. The output of the detector may be input to a bias adjuster, which outputs a dynamic voltage level supplied to at least one bias transistor in the amplifier. Multiple embodiments of the detector and bias adjuster are disclosed.
Claims32
An amplifier for amplifying an input signal to generate an output signal, the amplifier comprising a first bias transistor having a first bias level, the gain of the amplifier being a function of the first bias level, the amplifier further comprising:
- a first detector for measuring a first envelope of the output signal;
- and
- a first bias adjuster for shifting the voltage level of the output voltage of the first detector, the output of the first bias adjuster adjusting the first bias level.
A method for amplifying an input signal to generate an output signal, the amplifying comprising coupling an input signal to an amplifier to generate an output signal, the amplifier comprising a first bias transistor having a first bias level, the gain of the amplifier being a function of the first bias level, the method comprising:
- measuring a first envelope of the output signal with a first detector;
- shifting the voltage level of the measured envelope of the output signal with a first bias adjuster;
- and
- adjusting the first bias level with said shifted voltage level.
An amplifier for amplifying an input signal to generate an output signal, the amplifier comprising a first bias transistor having a first bias level, the gain of the amplifier being a function of the first bias level, the amplifier further comprising:
- means for measuring a first envelope of the output signal;
- and
- means for shifting the voltage level of the output voltage of the means for measuring a first envelope, the output of said means for shifting adjusting the first bias level.
An amplifier for amplifying an input signal to generate an output signal, the amplifier comprising:
- a first NMOS transistor for providing gain to the input signal;
- a first PMOS transistor for providing gain to the input signal, the output of the first NMOS transistor coupled to the output of the first PMOS transistor;
- a first bias transistor having a first bias level, the first bias transistor supplying a current for the first NMOS transistor and the first PMOS transistor;
- first mirror circuitry coupled to the first bias level, the current through the first mirror circuitry being a fixed proportion of the current through the first bias transistor;
- and
- a first auxiliary bias transistor coupled to the first mirror circuitry, the current through the first mirror circuitry further being said fixed proportion of the current through the first auxiliary bias transistor, the first auxiliary bias transistor further directly coupled to either the first NMOS transistor or the first PMOS transistor.
An amplifier for amplifying an input signal to generate an output signal, the amplifier comprising a first NMOS transistor for providing gain to the input signal, a first PMOS transistor for providing gain to the input signal, the output of the first NMOS transistor coupled to the output of the first PMOS transistor, the amplifier further comprising:
- a first bias transistor coupled to the first NMOS transistor, the first bias transistor having a first bias level;
- a second bias transistor coupled to the first PMOS transistor, the second bias transistor having a second bias level;
- first means for providing a current associated with the second bias transistor to the first NMOS transistor;
- and
- first means for providing a current associated with the first bias transistor to the first PMOS transistor.
Dependencies are inferred from the claim text.