Electronic device with correction function and method for correcting electronic device

Abstract

An apparatus and method for internally calibrating a direct conversion receiver (DCR) through feeding a calibration signal via ESD protection circuitry is disclosed. The apparatus includes an internal signal generator for generating a calibration signal, a front-end input stage for receiving an RF signal at an input node, an ESD protection unit for protecting against electrostatic discharge, and a switch unit coupled to the ESD protection unit, for selectively passing a calibration signal to the front-end input stage, whereby the connection of the switch unit and the ESD protection unit meansthat when the DCR is operating in normal mode, the switch unit will not affect the noise performance and matching of the receiver.

Description

technical field [0001] The present invention relates to the calibration of direct down-frequency receivers, especially an electronic device with calibration function and a method for calibrating an electronic device. Background technique [0002] The basic principle of the superheterodyne receiver is to convert the frequency band of the radio frequency signal to an intermediate frequency (IF) by mixing a radio frequency signal and a first adjustable local oscillator signal, and then mix the intermediate frequency signal and a second local oscillator signal to convert the IF signal to a baseband frequency. However, a direct conversion receiver (DCR) does not convert the radio frequency signal to the intermediate frequency signal first, but directly converts the radio frequency signal to the base frequency signal in one step. In the direct down frequency receiver, the frequency of the local oscillator signal is set to be the same as the RF signal to be converted, which means ...

AI Technical Summary

Problems solved by technology

When the switch unit 40 is turned off instead of turned on, although the switch unit 40 is not in operation, it is still directly coupled to the front-end input stage 20, which will cause some parasitic resistance and parasitic capacitance to appear in the direct down-conversion receiver 10, wherein the parasitic Resistors will introduce thermal noise into the circuit, greatly affecting the noise performance of the circuit and changing the characteristics of the receiver, while parasitic capacitance will affect the input matching conditions of the front-end circuit, thus reducing the existing technology directly down-converts the performance of the receiver 10

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