Noise suppression circuit and method for frequency modulator
A technology of noise suppression, frequency modulation machine, applied in the direction of modulation, simultaneous amplitude and angle modulation, electrical components, etc.
Inactive Publication Date: 2015-07-08
ZHEJIANG VOCATIONAL COLLEGE OF COMMERCE
View PDF3 Cites 0 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
[0004] In the existing frequency modulation machine, when the intermediate frequency amplifier circuit does not meet the requirements of the detection circuit, that is, when no frequency modulation signal is received, high frequency signals will pass through the intermediate frequency amplifier circuit 103 and the detection circuit 104, then input to the audio pre-amplification circuit 105 and the audio power amplification circuit 106 for power amplification, making the noise unbearable
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment Construction
[0079] The content of the present invention will be further described below in conjunction with the accompanying drawings.
[0080] like figure 2 As shown, it is a structural diagram of a FM machine with a noise suppression circuit, including a tuning circuit 101, a frequency conversion circuit 102, an intermediate frequency amplification circuit 103, a noise suppression circuit 107, a detection circuit 104, an audio pre-amplification circuit 105 and an audio power amplification circuit 106:
[0081] The tuning circuit 101 is for selecting a signal of a certain frequency;
[0082] The frequency conversion circuit 102 mixes the tuned signal 111 and the local oscillator to obtain an intermediate frequency signal 112;
[0083] The intermediate frequency amplifying circuit 103 amplifies the intermediate frequency signal 112 obtained by the frequency conversion circuit 102 so as to meet the requirements of the detection circuit 104;
[0084] The noise suppression circuit 107 is ...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
Login to View More Abstract
The invention discloses a noise suppression circuit and a noise suppression method for a frequency modulator. The frequency modulator with the noise suppression circuit comprises a tuning circuit, a frequency conversion circuit, an intermediate-frequency amplification circuit, the noise suppression circuit, a detecting circuit, an audio pre-amplification circuit and an audio power amplification circuit, wherein the tuning circuit is used for selecting a signal of certain frequency; the frequency conversion circuit mixes the signal selected by the tuning circuit and a local oscillator to obtain an intermediate-frequency signal; the intermediate-frequency amplification circuit amplifies the intermediate-frequency signal obtained by the frequency conversion circuit to meet the requirements of the detecting circuit; the noise suppression circuit suppresses noise produced when the frequency-modulated signal is not received; the detecting circuit demodulates an audio signal from an audio packet, and filters a high-frequency signal; the audio pre-amplification circuit performs open loop pre-amplification on the audio signal output by the detecting circuit; and the audio power amplification circuit performs closed loop amplification on the audio signal to drive a loudspeaker. By the circuit and the method, the noise produced when the frequency-modulated signal is not received can be effectively suppressed.
Description
technical field [0001] The invention relates to noise suppression technology, in particular to a noise suppression circuit and method for frequency modulation machines. Background technique [0002] figure 1 It is a structural diagram of an existing FM machine, including a tuning circuit 101 , a frequency conversion circuit 102 , an intermediate frequency amplifying circuit 103 , a detection circuit 104 , an audio pre-amplifying circuit 105 and an audio power amplifying circuit 106 . The tuning circuit 101 is to select a signal of a certain frequency; the frequency conversion circuit 102 is to mix the selected signal and the local oscillator to obtain an intermediate frequency signal; the intermediate frequency amplifying circuit 103 is for the frequency conversion circuit The intermediate frequency signal obtained by 102 is amplified so as to meet the requirements of the detection circuit; the detection circuit 104 is to demodulate the audio signal from the audio packet, a...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More Patent Type & Authority Patents(China)
IPC IPC(8): H03C5/00
Inventor 王文建
Owner ZHEJIANG VOCATIONAL COLLEGE OF COMMERCE