Amplitude shift keying (ASK)/on-off keying (OOK) radio frequency (RF) receiving circuit

Abstract

The invention provides an amplitude shift keying (ASK) / on-off keying (OOK) radio frequency (RF) receiving circuit. The receiving circuit is characterized in that after a low noise amplifier amplifies the received signal, the amplified received signal and local oscillation generated by an oscillator are jointly input into a mixer; the mixer reduces the frequency output by the low noise amplifier to intermediate frequency; the intermediate frequency signal output by the mixer is demodulated and output by a peak detection module after being amplified by a primary intermediate frequency amplifier, filtered by an intermediate frequency bandpass filter and amplified by a secondary intermediate frequency amplifier; a charge pump is driven after the peak detection output potential is compared with the fourth reference potential Vref4; the charge pump charges and discharges a capacitor to obtain gain control signals; the gain control signals are fed back to the low noise amplifier, the primary intermediate frequency amplifier and the secondary intermediate frequency amplifier to form an automatic gain control loop; and the low noise amplifier, the primary intermediate frequency amplifier and the secondary intermediate frequency amplifier respectively input the first, second and third reference potentials. The receiving circuit solves the problem of blocking during close range remote control, and meanwhile, the antijamming capability of the receiving circuit is improved and the cost is saved.

Description

technical field [0001] The invention relates to the field of signal and information processing, in particular to radio frequency receiving technology. Background technique [0002] Traditional remote control circuits, such as toy car remote control circuits, door and window remote control circuits, etc., mostly use ASK / OOK modulation, and their receiving circuits generally have two implementation methods: super regenerative circuit and super heterodyne circuit. The super regenerative circuit is widely used due to its low cost, simple circuit and high sensitivity. However, compared with the super heterodyne structure, it has problems such as difficulty in integration and weak anti-interference ability. [0003] The structure of a current superheterodyne radio frequency receiving circuit is as follows: figure 1 As shown, the signal received by the antenna is amplified by the low noise amplifier (11) and then down-converted to the intermediate frequency by the mixer (12) toget...

AI Technical Summary

Problems solved by technology

The above methods are widely used, but the digital method uses an analog-to-digital converter, which occupies a large chip area and power consumption, which is not conducive to cost reduction; and the analog method is used to ensure that the sensitivity of the receiving circuit is not affected. Loss, generally only controls the gain of the intermediate frequency amplifier or mixer, and if you want to increase the adjustment of the gain of the low noise amplifier to obtain a higher dynamic range, you generally need to use a complex gain controller (gain controller) to control the feedback signal After the operation is performed, the gain of each unit is controlled separately (such as image 3 shown)

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