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1. (WO2013113637) NOISE CANCELING LOW-NOISE AMPLIFIER

Pub. No.:    WO/2013/113637    International Application No.:    PCT/EP2013/051504
Publication Date: Fri Aug 09 01:59:59 CEST 2013 International Filing Date: Sat Jan 26 00:59:59 CET 2013
IPC: H03F 1/26
H03F 3/189
H03F 3/195
H03F 3/21
Applicants: TELEFONAKTIEBOLAGET L M ERICSSON (publ)
Inventors: MATTISSON, Sven
ANDERSSON, Stefan
Title: NOISE CANCELING LOW-NOISE AMPLIFIER
Abstract:
A noise-canceling LNA circuit (30) for amplifying signals at an operating frequency ƒ in a receiver circuit (10) is disclosed. The LNA circuit (30) comprises a first (42) and a second (46) amplifier branch, each having an input terminal (43, 47) connected to an input terminal (32) of the LNA circuit (30). The first amplifier branch (42) comprises an output terminal (44) for supplying an output current of the first amplifier branch (42) and a common source or common emitter main amplifier. The main amplifier has an input transistor (50) having a first terminal (52), which is a gate or base terminal, operatively connected to the input terminal (43) of the first amplifier branch, a shunt-feedback capacitor (60) operatively connected between the first terminal (52) of the input transistor (50) and a second terminal (54), which is a drain or collector terminal, of the input transistor (50), and an output capacitor (65) operatively connected between the second terminal (54) of the input transistor (50) and the output terminal (44) of the first amplifier branch (42). The second amplifier branch (46) comprises an output terminal (48) for supplying an output current of the second amplifier branch (46). The LNA circuit (30) comprises circuitry (68) for combining the output current of the first amplifier branch (42) and the output current of the second amplifier branch (46), thereby generating a total output current of the LNA circuit (30).