Wideband Low Noise Amplifier with Single-Ended to Differential Capability and Filtering

Abstract

The invention provides a broadband low-noise amplifier with single-end-to-difference capacity and a filtering function. The amplifier comprises three Gm stages, a feedback network and loads. The first Gm stage is connected with the second Gm stage in parallel, the two Gm stages connected in parallel are used as input, output of the first Gm stage enables differential signals to be converted into single-end signals through the feedback network, the single-end signals are fed back to a voltage input end to form a loop, and meanwhile, the output of the first Gm stage is overlapped with output of the second Gm stage through output of the third Gm stage. According to the broadband low-noise amplifier, broadband low noise amplification and LC narrowband filtering are realized, meanwhile, buffer stages or Gm stages do not need to be inserted between the first Gm stage and the second Gm stage, and therefore the linearity and the noise performance of the circuit are effectively improved. The broadband low-noise amplifier realizes the single-end-to-difference function and two routes of balanced output, and guarantees good IIP2 performance; a noise eliminating technology is used, and therefore transistor noise led in by impedance matching is eliminated.

Description

technical field [0001] The invention belongs to the technical field of communication, and relates to a low-noise amplifier, in particular to a wide-band low-noise amplifier with single-end conversion capability and filtering function. Background technique [0002] In the RF input front end of a wideband receiver, in addition to the most basic low-noise amplification and impedance matching requirements, other requirements often need to be met, including tracking filtering (TrackingFiltering), single-ended to differential, very stable second-order linearity, and lower and lower power consumption. A common way to meet these requirements is: After the radio frequency (RF) signal passes through a single-ended to differential network or a low-noise amplifier, it is connected to the filter load through the drive (Buffer) stage and the transconductance (Gm) stage to complete Narrowband tracking (tracking) filtering, and then through the drive (Buffer) stage to the mixer (Mixer). A...

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Problems solved by technology

[0008] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a broadband low noise amplifier with single-ended to differential capability and filtering effect, which is used to solve the problem that the structure of the broadband low noise amplifier in the prior art does not have a filtering effect , and it is difficult to achieve good linearity performance, noise performance and impedance matching performance at the same time

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