Difference simulation front end device for low-frequency signal detection and transmission system

Abstract

The invention discloses a difference simulation front end device for a low-frequency signal detection and transmission system. The device comprises a magnetic sensing module, a low-pass filter module, a difference amplification module and at least one conversion comparison module, wherein the magnetic sensing module, the low-pass filter module, the difference amplification module and the conversion comparison module are sequentially connected. Each conversion comparison module comprises a digital-to-analog convertor and a first difference comparator, an output end of the difference amplification module is connected with a difference input end of the related first difference comparator, and a difference output end of each digital-to-analog convertor is connected with a difference reference electrical level input end of the related first difference comparator. By adopting the technical scheme, the interference on a low-frequency signal received in the low-frequency signal detection and transmission system from circuit noise and environment noise can be reduced, the capability of inhibition on a common-mode electrical level is improved, and thus the precision on detection and control of a low-frequency alternating magnetic field distance is improved.

Description

technical field [0001] The invention relates to a differential analog front-end device used in a low-frequency signal detection and transmission system, which belongs to the communication field. Background technique [0002] Nowadays, there have been methods of adding a radio frequency function (called a radio frequency SIM card) to a SIM (Subscriber Identity Module, Subscriber Identity Module) card in a mobile phone or adding a short-distance communication module on the main board of the mobile phone to realize the short-distance communication of the 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. In this solution, the radio frequency SIM uses UHF...

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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