CN111464919A

CN111464919A - Electronic frequency divider based on FIR filter module

Info

Publication number: CN111464919A
Application number: CN202010259342.0A
Authority: CN
Inventors: 曾山
Original assignee: Maloney Guangzhou Technology Development Co ltd
Current assignee: Maloney Guangzhou Technology Development Co ltd
Priority date: 2020-04-03
Filing date: 2020-04-03
Publication date: 2020-07-28

Abstract

The invention discloses an electronic frequency divider based on an FIR (finite impulse response) filter module, which comprises the FIR filter module, a power amplifier, an L C low-pass filter module and a L C high-pass filter module, wherein the input end of the FIR filter module is electrically connected with the input end of an audio signal, the output end of the FIR filter module is electrically connected with the input end of the power amplifier, the output end of the power amplifier is respectively electrically connected with the input ends of a L C high-pass filter module and a L C low-pass filter module, the output end of a L C high-pass filter module is electrically connected with a high-pitch output end, and the output end of a L C low-pass filter module is electrically connected with a low-pitch output end.

Description

Electronic frequency divider based on FIR filter module

Technical Field

The present invention relates to an electronic frequency divider, and more particularly, to an electronic frequency divider based on an FIR filter module.

Background

As a professional sound amplification sound box, the characteristics of the sound amplification sound box are difficult to achieve ideally, so that the better sound amplification sound box can form a complete sound amplification system by using a digital audio processor in combination with the sound amplification sound box and a power amplifier. The common digital audio processor is internally provided with functions of frequency division, balance, gain, time delay, polarity, amplitude limiting and the like, and is matched with the sound box by adjusting functional parameters, so that the performance of the sound box is optimized.

At present, most professional sound reinforcement sound boxes are of 2-frequency division, 3-frequency division or 4-frequency division structures. Processors typically have multiple outputs, such as the common 2 in 4 out, 2 in 6 out, 4 in 8 out. In the existing active frequency dividing circuit, one output of a processor corresponds to a power amplifier of one channel to push one path of unit, the output channel of each path of processor is divided by frequency and the like and then is separately accessed to a power amplifier and a sound box unit of the corresponding frequency band, and the structure of the circuit is shown in fig. 1. Therefore, when the digital audio processor is used for system optimization, how many channels of frequency division are available for each loudspeaker box corresponds to how many channels of power amplifiers and how many channels of digital audio processor outputs, which results in a complex system and high cost.

However, as shown in fig. 2, although the conventional passive frequency division method does not need to use multiple power amplifiers, since the sensitivity of the treble unit of the professional sound box is much higher than the sensitivity of the midrange sound, and is generally higher than the sensitivity of the midrange sound by about 10 DBs, the general frequency divider design must perform attenuation processing on the treble channel, and the power of the treble unit is about 5-10 times smaller than that of the bass unit, so that the attenuation element of the frequency divider bears most of power, and the heat generation is relatively large, and a high-power resistor with a heat sink of 100 plus 200W must be used.

Disclosure of Invention

In order to overcome the defects of the prior art, an object of the present invention is to provide an electronic frequency divider based on FIR (finite impulse response), which utilizes the characteristic that an FIR filter module can independently and separately process the amplitude and the phase, and compensates the phase shift generated by a passive frequency dividing element into linear phases in a processing channel, thereby avoiding the need of setting multiple power amplifier channels; and the FIR filter module is used for separately setting gains of different frequency bands and attenuating the high-pitch frequency band, so that the passive frequency divider only performs frequency division processing but does not perform attenuation, a high-power resistor in the passive frequency divider can be cancelled, the heating phenomenon of the frequency divider is greatly reduced, the reliability of the frequency divider is improved, and the cost of the frequency divider is reduced.

One of the purposes of the invention is realized by adopting the following technical scheme:

an electronic frequency divider based on an FIR (finite impulse response) filter module comprises the FIR filter module, a power amplifier, an L C low-pass filter module and a L C high-pass filter module, wherein the input end of the FIR filter module is electrically connected with an audio signal input end, the output end of the FIR filter module is electrically connected with the input end of the power amplifier, the output end of the power amplifier is electrically connected with the input end of the L C high-pass filter module, the output end of the power amplifier is also electrically connected with the input end of the L C low-pass filter module, the output end of the L C high-pass filter module is electrically connected with a treble output end, and the output end of the L C low-pass filter module is electrically.

Further, the L C high-pass filter module includes a first capacitor and a first inductor, one end of the first capacitor is electrically connected to the output terminal of the power amplifier, the other end of the first capacitor is grounded through the first inductor, and one end of the first capacitor connected to the first inductor is electrically connected to the treble output terminal.

Further, the L C low-pass filter module includes a second capacitor and a second inductor, one end of the second inductor is electrically connected to the output terminal of the power amplifier, the other end of the second inductor is grounded through the second capacitor, and one end of the second inductor connected to the second capacitor is electrically connected to the bass output terminal.

Further, the high pitch output end is connected with a high pitch loudspeaker, and the low pitch output end is connected with a medium and low pitch loudspeaker.

Compared with the prior art, the invention has the beneficial effects that:

according to the electronic frequency divider based on the FIR filter module, by utilizing the characteristic that the FIR filter module can independently and separately process the amplitude and the phase, the phase shift generated by the passive frequency dividing element is compensated into a linear phase in one processing channel, so that the problem that different processing channels are required to set different delays for phase coupling is solved, and a plurality of paths of power amplifier channels are not required to be set; and the FIR filter module is used for separately setting gains of different frequency bands and attenuating the high-pitch frequency band, so that the passive frequency divider only performs frequency division processing but does not perform attenuation, a high-power resistor in the passive frequency divider can be cancelled, the heating phenomenon of the frequency divider is greatly reduced, the reliability of the frequency divider is improved, and the cost of the frequency divider is reduced.

Drawings

Fig. 1 is a circuit configuration diagram of a conventional active divide-by-two circuit;

FIG. 2 is a circuit diagram of a conventional passive divide-by-two circuit;

fig. 3 is a circuit structure diagram of an electronic frequency divider based on an FIR filter module according to the present invention;

FIG. 4 is a phase and amplitude comparison diagram of an electronic frequency divider based on an FIR filter module according to the present invention and an existing active divide-by-two circuit;

FIG. 5 is a phase and amplitude comparison diagram of an electronic frequency divider based on an FIR filter module according to the present invention and a conventional passive divide-by-two circuit;

FIG. 6 is a schematic diagram of a FIR filter block;

fig. 7 is a block diagram of an FIR filter block.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and the detailed description, and it should be noted that any combination of the embodiments or technical features described below can be used to form a new embodiment without conflict.

Please refer to fig. 3, which is a circuit structure diagram of an electronic frequency divider based on an FIR filter module, the electronic frequency divider includes an FIR filter module, a power amplifier, an L C low-pass filter module, and a L C high-pass filter module, an input end of the FIR filter module is electrically connected to an audio signal input end, an output end of the FIR filter module is electrically connected to an input end of the power amplifier, an output end of the power amplifier is electrically connected to an input end of the L C high-pass filter module, an output end of the power amplifier is also electrically connected to an input end of the L C low-pass filter module, an output end of the L C high-pass filter module is electrically connected to a treble output end, and an output end of the L C low-pass filter module is electrically.

Fir (finite Impulse response) filter: the finite-length unit impulse response filter, also called non-recursive filter, is the most basic element in digital signal processing system, it can guarantee arbitrary amplitude-frequency characteristic and at the same time has strict linear phase-frequency characteristic, and its unit sampling response is finite-length, so that the filter is stable system. Referring to fig. 6 and 7, the FIR filter block operates on the principle of multiplying the latest n data samples by a series of constants (called tap coefficients) and summing the resulting array of cells. By varying the weighting (value) of the coefficients and the number of filter taps, the FIR filter can achieve virtually any desired frequency response characteristic.

Fig. 4 and fig. 5 are phase and amplitude comparison diagrams of an electronic frequency divider based on an FIR filter module according to the present invention, and an existing active frequency-halving circuit and an existing passive frequency-halving circuit, respectively. As can be seen from the figure, the phase curve and the amplitude-frequency response curve of the electronic frequency divider based on the FIR filter module provided by the invention are substantially flat at medium and high frequencies, relative to the active frequency-dividing circuit and the passive frequency-dividing circuit.

As a preferred implementation mode, the L C high-pass filter module comprises a first capacitor and a first inductor, one end of the first capacitor is electrically connected with the output end of the power amplifier, the other end of the first capacitor is grounded through the first inductor, and one end of the first capacitor connected with the first inductor is electrically connected with the treble output end.

Preferably, the high pitch output end is connected with a high pitch loudspeaker, and the low pitch output end is connected with a medium and low pitch loudspeaker.

The above embodiments are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited thereby, and any insubstantial changes and substitutions made by those skilled in the art based on the present invention are within the protection scope of the present invention.

Claims

1. An electronic frequency divider based on an FIR (finite impulse response) filter module is characterized by comprising the FIR filter module, a power amplifier, an L C low-pass filter module and a L C high-pass filter module, wherein the input end of the FIR filter module is electrically connected with the input end of an audio signal, the output end of the FIR filter module is electrically connected with the input end of the power amplifier, the output end of the power amplifier is electrically connected with the input end of the L C high-pass filter module, the output end of the power amplifier is also electrically connected with the input end of the L C low-pass filter module, the output end of the L C high-pass filter module is electrically connected with a treble output end, and the output end of the L C low-pass filter module is.

2. The FIR filter block-based electronic frequency divider of claim 1, wherein the L C high-pass filtering block comprises a first capacitor and a first inductor, one end of the first capacitor is electrically connected to the output terminal of the power amplifier, the other end of the first capacitor is grounded through the first inductor, and one end of the first capacitor connected to the first inductor is electrically connected to the treble output terminal.

3. The FIR filter block-based electronic frequency divider of claim 1, wherein the L C low-pass filtering block comprises a second capacitor and a second inductor, one end of the second inductor is electrically connected to the output terminal of the power amplifier, the other end of the second inductor is grounded via the second capacitor, and one end of the second inductor connected to the second capacitor is electrically connected to the bass output terminal.

4. The FIR filter module-based electronic frequency divider of claim 1, wherein a tweeter is connected to the treble output and a midbass speaker is connected to the bass output.