amplifying circuit

Abstract

An amplification circuit (100) comprising a first filter (102) and an LNA (110). The first filter (102) comprising an input (104) for receiving an input signal; a first differential output (106); and a second differential output (108). The first filter (102) has a differential mode of operation for frequencies in its pass-band (706, 806) and a common mode of operation for frequencies outside its pass-band (706, 806), and may be an acoustic wave filter. The LNA (110) comprising a first differential input (112) connected to the first differential output (106) of the first filter (102); a second differential input (114) connected to the second differential output (108) of the first filter (102); and an output (116) for providing an amplified output signal.

Description

technical field [0001] This application relates to amplification circuits and in particular, though not necessarily, to amplification circuits for use in global positioning system receivers. Background technique [0002] Amplifying circuits generally have the problem of poor nonlinear performance (for example, in IM2 and IM3 suppression), and existing amplifying circuits require many surface-mounted devices or components. Contents of the invention [0003] According to a first aspect of the present invention, an amplifying circuit is provided, comprising: [0004] First filter, including: [0005] an input terminal for receiving an input signal; [0006] a first differential output; and [0007] a second differential output; [0008] wherein the first filter performs differential-mode operation for frequencies within its passband and common-mode operation for frequencies outside its passband; and [0009] Low Noise Amplifiers (LNAs), including: [0010] a first diffe...

AI Technical Summary

Problems solved by technology

[0002] Amplifying circuits usually have poor nonlinear performance (for example, in terms of IM2 and IM3 suppression), and existing amplifying circuits require more surface mount devices or components

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