Radio frequency amplitude keying demodulation circuit with large input dynamic range

Abstract

The invention discloses a radio frequency amplitude keying demodulation circuit with large input dynamic range, which comprises an amplitude detection circuit, a Gaussian filter circuit, a peak detection circuit and two branches of difference amplitude keying demodulation circuits of a comparison circuit. The amplitude detection circuit is formed by a fixed gain amplifier with S poles in series connection and an amplitude detection and conversion circuit. Each branch of the amplitude keying demodulation circuits includes that input signals are amplified to i fuzzy amplitude keying signals through the amplitude detection circuit, the i fuzzy amplitude keying signals are added and converted into high-low voltage amplitude signals, high frequency components are filtered through the Gaussian filter circuit, the filtered signals pass through the peak detection circuit to obtain high-low average amplitude signals, and the average amplitude signals and the signals filtered by the Gaussian filter circuit are compared through the comparison circuit to obtain demodulation signals output by the radio frequency amplitude keying demodulation circuit. The radio frequency amplitude keying demodulation circuit with the large input dynamic range can be flexibly used for demodulating amplitude detection signals with modulation degree ranging from 0.5 to 0.9, thereby being capable of being applied to the front end of a radio frequency receiver with input signals reaching up to 60dB dynamic range.

Description

Background technique [0001] In recent years, with the wide application of intermittent low-speed products, such as home security, garage door management and remote control, short-distance wireless communication technology has been widely used, and the amplitude keying modulation method used in short-distance wireless communication technology has become more and more popular . Because the amplitude keying modulation method has simple modulation, simple system design, low system power consumption, and bit error rate increases with the increase of signal propagation distance, it is especially suitable for short-distance wireless communication occasions. [0002] As we all know, different systems have different depths of amplitude keying modulation. Obviously, a demodulator that can only be applied to one modulation method can only meet a specific system requirement, and cannot adapt to the specific needs of different systems. At the same time, the traditional The sensitivity of ...

AI Technical Summary

Problems solved by technology

There are many disadvantages in the prior art amplitude keying demodulation: First, because its receiving sensitivity is mainly determined by the gain of its front-end amplifier circuit, and the relationship between the gain and sensitivity of its front-end amplifier circuit presents an exponential relationship, it is necessary to greatly improve the sensitivity. Greatly increase the gain of its front-end amplifier circuit, but due to power consumption, noise, etc., the gain of its front-end amplifier circuit cannot be too large, so this limits the detection of high-sensitivity input signals by the existing circuit structure

Second, the traditional design requires additional filter capacitors and inductors, which not only increases the difficulty of system design, but also increases the complexity of the peripheral circuits of the chip

Third, in the traditional design, because the comparison voltage of the comparison circuit adopts a fixed level, the traditional design cannot be applied to systems with different modulation degrees. The existing technology generally first determines the modulation degree, and then changes the chip The external control signal changes the comparison level of the comparison circuit, but in practical applications, the signal may affect its modulation degree due to uncertain factors such as noise, which affects the output bit error rate of the traditional design

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