Frequency modulation broadcast frequency measurement demodulation electronic system
A technology of FM broadcasting and electronic systems, which is applied in the direction of broadcasting receiving circuits, transmission systems, digital transmission systems, etc., can solve the problems of limited use of FM broadcasting monitoring and demodulation systems and cannot meet the requirements of use, and achieve accurate center frequency and communication Frequency band, fewer circuit elements, and the effect of reducing distortion
Active Publication Date: 2020-08-04
JILIN INST OF RADIO & TELEVISION
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Problems solved by technology
[0007] In order to solve the problem that the existing FM broadcast monitoring and demodulation system is limited in use and cannot meet its use requirements, the present invention provides an FM broadcast frequency measurement and demodulation electronic system
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specific Embodiment approach 1
[0021] Specific implementation mode 1. Combination figure 1 Describe this embodiment, the FM radio frequency measurement and demodulation electronic system, the system includes the input terminal INPUT, the clock input terminal OSC171M, the sampling output terminal CLK76, the data output terminal AUDIO, the capacitor C1, the capacitor C2, the resistor R1, the resistor R2, and the resistor R3 , resistor R4, operational amplifier U1, D flip-flop U3, AND gate U4, D flip-flop U5, synchronous enable counter U6, synchronous clear counter U7, synchronous enable latch U8, synchronous frequency divider U9, lock Register U10, latch U12, multiplier U11, divider U15, subtractor U16, constant output U14 and divider U13;
[0022] The input terminal INPUT is connected to the capacitor C1, and the capacitor C1 is respectively connected to the resistor R2, the resistor R3, the resistor R4, and the positive input terminal of the operational amplifier U1; the capacitor C2 is respectively connect...
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The invention discloses a frequency modulation broadcast frequency measurement demodulation electronic system, relating to the field of radio and television. The problems are solved that an existing frequency modulation broadcast monitoring demodulation system is limited in use, and the use requirements cannot be met. The electronic system comprises an input end INPUT, a clock input end, a sampling output end, a data output end, two capacitors, four resistors, an operational amplifier, a D trigger, an AND gate, a D trigger, a synchronous enable counter, a synchronous reset counter, a synchronous enable latch, a synchronous frequency divider, a latch, a latch, a multiplier, a divider, a subtracter, a constant output device and a divider. According to the invention, a frequency discriminator, an analog-to-digital converter and an amplification circuit connected between the frequency discriminator and the analog-to-digital converter which are necessary in traditional demodulation equipment can be canceled, and distortion is reduced while the cost is reduced; few circuit elements are needed; demodulating is performed to obtain an audio program content digital data stream which can be directly played, stored or transmitted; due to the fact that quadruple sampling program signals of pilot frequency signal frequency are adopted, hardware does not need to be used for extracting pilot frequency signals in the subsequent stereophonic decoding process.
Description
technical field [0001] The invention relates to the field of broadcasting and television, in particular to an electronic system for measuring and demodulating frequency modulation broadcasting. Background technique [0002] The national standard of FM broadcasting in my country stipulates that FM broadcast programs adopt frequency modulation, the maximum frequency deviation is 75Khz, the left and right stereo channels use suppressed carrier double-sided band to modulate the 38KHz carrier, and divide the carrier frequency by two to become a pilot signal, which is FM together with the program signal Transmission; the traditional program demodulation method is to demodulate the intermediate frequency signal with a frequency discriminator to obtain an audio analog signal, and then use an analog-to-digital converter to convert it into a digital sound data stream after amplification; in this conversion process, the analog signal experienced by the program signal There are many links...
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Login to View More IPC IPC(8): H04H40/45H04L7/00
CPCH04H40/45H04L7/0079
Inventor 焦杰
Owner JILIN INST OF RADIO & TELEVISION