Differential analog front end device used for low-frequency signal detection and transmission system

Abstract

The invention relates to a differential analog front end device used for a low frequency signal detection and transmission system, which is used in a short distance communication system. The differential analog front end device comprises at least one magnetic sensing module, at least one low-pass filter module, at least one amplifier, at least one digital / analog converter and at least one comparator, wherein the magnetic sensing module, the low-pass filter module and the amplifier are connected in sequence; the output end of the amplifier is connected with the forward input end of the comparator; the output end of the digital / analog converter is connected with the reverse input end of the comparator; and the amplifier is a differential amplifier. The differential analog front end device provided by the invention can reduce the interference of circuit noise and environment noise to low-frequency signal detection and a low-frequency signal received in a low-frequency signal, thereby improving the precision for detecting and controlling the high and low frequency alternating magnetic field distances.

Description

technical field [0001] The invention relates to the communication field, in particular to a differential analog front-end device used in a low-frequency signal detection and transmission system, and a method for detecting low-frequency signals using the device. Background technique [0002] Nowadays, there has been a method of adding a radio frequency function (called a radio frequency SIM card) on a SIM (Subscriber Identity Module, Subscriber Identity Module) card in a mobile phone or adding a short-range communication module on a mobile phone motherboard to realize short-distance communication of a mobile phone. The emergence of this method makes the mobile phone a super intelligent terminal that can recharge, consume, trade and authenticate, which greatly meets the urgent needs of the market. [0003] Among them, the mobile phone short-distance solution based on radio frequency SIM has attracted wide attention due to its simplicity and no need to change the mobile phone. ...

AI Technical Summary

Problems solved by technology

However, due to the different internal structures of different mobile phones, there are great differences in the radio frequency signal transmission effect. The radio frequency communication distance of the radio frequency SIM card of the mobile phone with strong transmission may reach a distance of several meters, and the communication distance of the radio frequency SIM card of the mobile phone with weak transmission can also reach tens of centimeters

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