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

Abstract

An analog front end device for low frequency signal detection and transmission system is provided by the present invention, which is applied to short distance communication system, and includes: at least one magnetic induction module, at least one low pass filtering module, at least one amplifier, at least one digital / analog converter and at least one comparator, said magnetic induction module, said low pass filtering module, and said amplifier are connected in succession, the output port of said amplifier is connected with the positive input port of said comparator, the output port of said digital / analog converter is connected with the negative input port of said comparator, said amplifier is an amplifier with double input port and single output port. The present invention can reduce the interference of circuit noise and environment noise on the low frequency signal received by the low frequency signal detection and transmission system, thereby can improve the accuracy of distance detection and control of low frequency alternating magnetic field.

Description

technical field [0001] The invention relates to the communication field, in particular to an analog front-end device used in a low-frequency signal detection and transmission system. 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. When the mobile phone is inside, the radio frequency signal can still be trans...

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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