Methods and apparatus for improving the operation of a variable gain amplifier (VGA)
AssigneeNokia Corporation
InventorsSami Varra, Sami Vilhonen
Life of this patent
Estimating the term…
Abstract
Disclosed is an RF transmitter circuit (10), as well as a method for operating the circuit. The RF transmitter circuit includes a VGA (20), that includes circuitry for generating a feedback signal, and a temperature compensation block (18) having an input coupled to a gain control signal and an output coupled to an input of the VGA for providing to the VGA a compensated gain control signal. The temperature compensation block further includes a bias input that receives the VGA feedback signal. The VGA feedback signal operates to modify the gain control signal to reduce an amount of variability in a VGA gain slope over a range of VGA output power.
Claims25
A method to operate a variable gain amplifier (VGA), comprising:
- applying a gain control signal to the VGA through a temperature compensation block;
- and
- feeding back to the temperature compensation block a bias signal generated by the VGA, the bias signal operating to modify the gain control signal to reduce variability in a VGA gain slope over a range of VGA output power.
An RF transmitter circuit comprising:
- a variable gain amplifier (VGA) comprising circuitry for generating a feedback signal;
- and
- a temperature compensation block having an input coupled to a gain control signal and an output coupled to an input of said VGA for providing to said VGA a compensated gain control signal, said temperature compensation block further comprising a bias input coupled to said VGA feedback signal, said VGA feedback signal operating to modify the gain control signal to reduce variability in a VGA gain slope over a range of VGA output power.
A mobile station that comprises an RF transmitter circuit, said RF transmitter circuit comprising a variable gain amplifier (VGA) coupled between an up-conversion mixer and a power amplifier, said VGA receiving a gain control signal via a temperature compensation block, characterized by said VGA comprising circuitry for generating a feedback signal and said temperature compensation block comprising an input coupled to said feedback signal, said feedback signal operating to modify the gain control signal to reduce variability in a VGA gain slope over a range of VGA output power.
Dependencies are inferred from the claim text.