Merged low-noise amplifier and balun
AssigneeTelefonaktiebolaget L M Ericsson (publ)
InventorHenrik Sjöland
Life of this patent
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Abstract
An RF amplifier can include a differential inductor for single-ended-to-differential signal conversion. With a center tap of the differential inductor coupled to signal ground and the RF input signal coupled to one of the end taps of the inductor, the negative of the RF input signal is obtained at the other end tap of the inductor. The differential RF signal produced can be coupled to a differential transistor amplifier that has cross-coupling capacitances, improving the signal balance of the differential output signal.
Claims20
An electronic amplifier for receiving a single-ended input signal and generating a differential output signal, comprising:
- at least two transistors arranged in a differential configuration, wherein the at least two transistors have respective first terminals for receiving signals to be amplified, and a control terminal of a first one of the at least two transistors is coupled through a first capacitance to the first terminal of a second one of the at least two transistors, and a control terminal of the second one of the at least two transistors is coupled through a second capacitance to the first terminal of the first one of the at least two transistors;
- and
- a center-tapped differential inductor for converting the single-ended input signal into a differential signal to be amplified, wherein a center tap of the differential inductor is coupled to signal ground, the single-ended input signal is provided to an end tap of the differential inductor, and the differential signal to be amplified is provided at end taps of the differential inductor.
A method, in an electronic circuit, of generating a differential electronic signal from a single-ended electronic signal, comprising the steps of:
- arranging at least two transistors in a differential configuration, wherein the at least two transistors have respective first terminals for receiving signals to be amplified;
- capacitively coupling a control terminal of a first one of the at least two transistors to the first terminal of a second one of the at least two transistors;
- capacitively coupling a control terminal of a second one of the at least two transistors to the first terminal of the first one of the at least two transistors;
- and
- converting the single-ended input signal into a differential signal to be amplified, wherein the converting step comprises coupling a center tap of a differential inductor to signal ground, providing the single-ended input signal to an end tap of the differential inductor, and providing the differential signal to be amplified at end taps of the differential inductor.
Dependencies are inferred from the claim text.