A noise-suppressed amplifier with a signal-nulled feedback for wideband applications

Abstract

This paper presents a noise suppression technique that is based on the feedback topology for wideband low-noise amplifiers. By nulling the signal in the noise feedback loop, the noise suppression and the signal performance like gain, input matching and output linearity can be considered independently. The overhead on power dissipation is small since the extra loop has less linearity concern. To demonstrate its feasibility, a shuntfeedback type LNA with the proposed noise suppression loop is implemented in a 0.18 m CMOS process. The signal bandwidth is 1.3GHz. The voltage gain and noise figure are 14.1dB and 4.8dB respectively. The current consumption is 1.18mA from a 1.3V supply voltage.Index Terms-shunt-amplifiers, wide band, noise suppression.

A Power-Efficient Noise Canceling Technique Using Signal-Suppression Feed-Forward for Wideband LNAs

“…Though having these advantages, this solution has a drawback that the power consumption of the noise-canceling amplifier A v,c tends to be comparatively large. In this paper, a signal-suppression technique, which applies the signal-null technique [2] [3], is proposed to suppress the power consumption of the noise-canceling amplifier. By exploiting an inverting amplifier where the output is the inverse of the input, the small-signal input of the noise-canceling amplifier A v,c can be suppressed.…”