FSK receiver

Abstract

A receiver includes a band-pass filter that limits a passband of an IF (Intermediate Frequency) signal, an FSK detector that detects the IF signal passing through the band-pass filter to generate a detection signal, and a control block that controls a modulation sensitivity of the FSK detector and a pass bandwidth of the band-pass filter, in which the control block controls the modulation sensitivity of the FSK detector according to the pass bandwidth of the band-pass filter.

Description

technical field [0001] The present invention relates to a receiver having an intermediate frequency, such as a single conversion system and a low intermediate frequency (low-IF) system, and more particularly, to a receiver utilizing an IF bandpass filter and an FSK detector. Background technique [0002] In recent years, reduction in size and power consumption of communication devices such as ISM (Industrial Scientific Medical) bands or designated low-power radio devices has been required, and many functions have been handled by ICs (Integrated Circuits). Likewise, receivers used with them also have functional circuits made into ICs, such as LNAs, mixers, IF filters, oscillators, PLL (Phase Locked Loop) frequency synthesizers, demodulators, and so on. Furthermore, in receivers mainly used for Remote Keyless Entry (RKE) / Tire Pressure Sensor (TPMS: Tire Pressure Monitoring System), many IF filters have been incorporated. Accordingly, the IF frequency has been changed from the...

AI Technical Summary

Problems solved by technology

When the modulation sensitivity is low, the output voltage difference ΔV is small, which makes detection difficult

However, when the modulation sensitivity is too high, the detectable range becomes smaller

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