Dual-band multi-gain control low-noise amplifier

Abstract

The invention discloses a dual-band multi-gain control low-noise amplifier, which comprises a frequency selection circuit, a main amplification circuit, a first programmable resistance attenuation network ATT, a second programmable resistance attenuation network ATT and a switch SW1, and is characterized in that the frequency selection circuit, the main amplification circuit, the first programmable resistance attenuation network ATT and the second programmable resistance attenuation network are sequentially connected in series; the switch SW1 is connected in parallel with a series branch formed by the first programmable resistance attenuation network ATT and the second programmable resistance attenuation network. The resistance attenuation network is located at the rear end of the main amplification circuit, according to a noise coefficient cascade formula, it can be known that the influence of a rear stage on a noise coefficient is lower than that of a front stage, a signal is amplified through the main amplification circuit firstly, noise introduced by the resistance network cannot be amplified, and therefore the noise coefficient of the whole circuit is improved.

Description

technical field [0001] The invention belongs to the low-noise amplifier technology, in particular to a dual-band multi-gain control low-noise amplifier. Background technique [0002] The LNA is one of the most important modules in the GPS RF receiver system, because it is located at the front end of the RF receiver. In order to ensure the transmission of the maximum power signal, the LNA needs to perform well on the RF filter of the previous stage. In addition, the noise performance of the LNA directly affects the noise figure and system sensitivity of the receiver system and its dynamic operating range because of its positional relationship. Compared with other common amplifiers, the RF low noise amplifier is characterized by amplifying the signal of the system without introducing additional noise to ensure the normal operation of the system. In a multi-stage connected system, the noise figure of the system is mainly determined by the noise figure of the previous module, b...

AI Technical Summary

Problems solved by technology

However, the disadvantage of this structure is that a lot of inductors are used, and the number of inductors is controlled by switches, which increases the chip area and cost.

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