Local oscillator phase-locked loop circuit board structure for suppressing 5G mobile phone interference in C frequency band

Abstract

The utility model relates to the technical field of amplifiers, and discloses a C-band local oscillator phase-locked loop circuit board structure for suppressing 5G mobile phone interference, which comprises a circuit board body, and the circuit board body is provided with a signal access port, a radio frequency amplification circuit, a radio frequency comb band-pass filter, a phase-locked loop oscillation circuit, an intermediate frequency LC band-pass filter circuit, an LDO (Low Dropout Regulator) chip and an output end. According to the local oscillator phase-locked loop circuit board structure for suppressing 5G mobile phone interference in the C frequency band, after a signal is amplified by the vertical polarization first-stage radio frequency amplification circuit and the horizontal polarization first-stage radio frequency amplification circuit, the gain of the radio frequency signal and the signal-to-noise ratio can be improved, so that the circuit signal is stable, and the signal quality is improved; after signals transmitted from the vertical polarization first-stage radio frequency amplification circuit and the horizontal polarization first-stage radio frequency amplification circuit pass through the phase-locked loop oscillation circuit, the stability of local oscillation signals is ensured, the circuit is simple and reasonable in arrangement, the processing and manufacturing procedures are simplified, the labor cost is reduced, and the circuit is suitable for batch production.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of amplifiers, in particular to a low-noise down-conversion amplifier, and specifically relates to a C-band local oscillator phase-locked loop circuit board structure for suppressing 5G mobile phone interference. BACKGROUND

[0002] An LNB (low noise block downconverter) can be generally divided into a C-band LNB (3.4GHz-4.2GHz) and a KU-band LNB (10.7GHz-12.75GHz). Because all satellite signals are quite weak before reaching an antenna and the higher the frequency is, the greater the signal loss is in coaxial cable transmission, an LNB is needed to amplify the signals, and the signal-to-noise ratio should not be deteriorated too much. The working process of the LNB is to amplify the satellite high-frequency signals first, and then convert the high-frequency satellite signals to an intermediate frequency (950MHz-2150MHz (depending on the intermediate frequency range of the LNB)) by using a local oscillator circuit and amplify the signals again, so as to facilitate the transmission of the coaxial cable and the demodulation and working of the satellite receiver.

[0003] At present, the common circuit board structure for the LNB has a complex circuit arrangement, a complex processing and manufacturing procedure, and high labor cost, and is not suitable for batch production. CONTENT OF THE INVENTION

[0004] The application aims to provide a C-band local oscillator phase-locked loop circuit board structure for suppressing 5G mobile phone interference, so as to solve the technical problems in the background art.

[0005] To achieve the above-mentioned purpose, the application discloses the following technical scheme: a C-band local oscillator phase-locked loop circuit board structure for suppressing 5G mobile phone interference, comprising a circuit board body, wherein a signal inlet, a radio frequency amplification circuit, a radio frequency comb-shaped bandpass filter, a phase-locked loop oscillation circuit, an intermediate frequency LC bandpass filter circuit, an LDO chip and an output end are arranged on the circuit board body.

[0006] The signal inlet comprises a vertical polarization signal inlet hole and a horizontal polarization signal inlet hole.

[0007] The radio frequency amplification circuit comprises a vertical polarization first-stage radio frequency amplification circuit, a horizontal polarization first-stage radio frequency amplification circuit and a second-stage radio frequency amplification circuit.

[0008] The vertical polarization signal access hole is connected with the vertical polarization first-stage radio frequency amplification circuit, the horizontal polarization signal access hole is connected with the horizontal polarization first-stage radio frequency amplification circuit, the vertical polarization first-stage radio frequency amplification circuit and the horizontal polarization first-stage radio frequency amplification circuit are connected with the second-stage radio frequency amplification circuit respectively, the second-stage radio frequency amplification circuit is connected with the radio frequency comb-shaped band-pass filter, and the vertical polarization first-stage radio frequency amplification circuit, the horizontal polarization first-stage radio frequency amplification circuit, the second-stage radio frequency amplification circuit and the radio frequency comb-shaped band-pass filter are connected with the phase-locked loop oscillation circuit respectively, and the second-stage radio frequency amplification circuit is connected with the LDO chip.

[0009] The phase-locked loop oscillation circuit is connected with the intermediate frequency LC band-pass filter circuit, and the intermediate frequency LC band-pass filter circuit is connected with the output end.

[0010] Preferably, the radio frequency comb-shaped band-pass filter is a 3.7GHZ-4.2GHZ radio frequency comb-shaped band-pass filter.

[0011] Preferably, the intermediate frequency LC band-pass filter circuit is a 950MHz-1450MHz intermediate frequency LC band-pass filter.

[0012] Preferably, the phase-locked loop oscillation circuit at least comprises a phase-locked loop oscillator, an intermediate frequency amplification circuit, a polarization switching circuit and a power supply circuit of a radio frequency amplification circuit, the phase-locked loop oscillator, the intermediate frequency amplification circuit, the polarization switching circuit and the power supply circuit of the radio frequency amplification circuit constitute an integrated circuit, and the phase-locked loop oscillator is connected with a crystal oscillator outside the integrated circuit.

[0013] Beneficial effects: the C-band 5G mobile phone interference suppression local oscillator phase-locked loop circuit board structure of the application can improve the gain of the radio frequency signal and improve the signal-to-noise ratio when the signal is accessed to the vertical polarization first-stage radio frequency amplification circuit and the horizontal polarization first-stage radio frequency amplification circuit, so as to stabilize the circuit signal and improve the signal quality, and the stability of the local oscillator signal is ensured after the signal output from the vertical polarization first-stage radio frequency amplification circuit and the horizontal polarization first-stage radio frequency amplification circuit passes through the phase-locked loop oscillation circuit. The C-band 5G mobile phone interference suppression local oscillator phase-locked loop circuit board structure of the application has simple circuit, reasonable arrangement, high product stability and reliability, simple manual operation process in the production process, accurate frequency phase locking, simplified processing and manufacturing process, reduced labor cost, and is suitable for batch production. BRIEF DESCRIPTION OF DRAWINGS

[0014] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Fig. 1 A schematic diagram of the overall structure of the local oscillator phase-locked loop circuit board for suppressing 5G mobile phone interference in the C-band provided in this application embodiment;

[0016] Fig. 2 A schematic diagram of the circuit connection of the local oscillator phase-locked loop circuit board structure for suppressing 5G mobile phone interference in the C-band provided in this application embodiment.

[0017] Reference numerals: 100, Vertical polarization signal input port; 110, Horizontal polarization signal input port; 210, Vertical polarization first-stage RF amplifier circuit; 220, Horizontal polarization first-stage RF amplifier circuit; 230, Second-stage RF amplifier circuit; 300, RF comb bandpass filter; 400, Phase-locked loop oscillator circuit; 500, Intermediate frequency LC bandpass filter circuit; 600, LDO chip; 700 and output terminal. Detailed Implementation

[0018] The technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0019] In this document, the term "comprising" is intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0020] Please see Figs. 1-2

[0021] This embodiment discloses a local oscillator phase-locked loop circuit board structure for suppressing 5G mobile phone interference in the C-band, including a circuit board body, on which a signal input, an RF amplifier circuit, an RF comb bandpass filter 300, a phase-locked loop oscillation circuit 400, an intermediate frequency LC bandpass filter circuit 500, an LDO chip 600 and an output terminal 700 are provided.

[0022] Specifically: the signal input includes a vertically polarized signal input hole 100 and a horizontally polarized signal input hole 110;

[0023] The radio frequency amplifier circuit includes a vertically polarized first-stage radio frequency amplifier circuit 210, a horizontally polarized first-stage radio frequency amplifier circuit 220, and a second-stage radio frequency amplifier circuit 230;

[0024] The vertical polarization signal access hole 100 is connected to the vertical polarization primary RF amplifier circuit 210, the horizontal polarization signal access hole 110 is connected to the horizontal polarization primary RF amplifier circuit 220, the vertical polarization primary RF amplifier circuit 210 and the horizontal polarization primary RF amplifier circuit 220 are respectively connected to the secondary RF amplifier circuit 230, the secondary RF amplifier circuit 230 is connected to the RF comb bandpass filter 300, the vertical polarization primary RF amplifier circuit 210, the horizontal polarization primary RF amplifier circuit 220, the secondary RF amplifier circuit 230 and the RF comb bandpass filter 300 are respectively connected to the phase-locked loop oscillation circuit 400, and the secondary RF amplifier circuit 230 is connected to the LDO chip 600;

[0025] The phase-locked loop oscillation circuit 400 is connected to the intermediate frequency LC bandpass filter circuit 500, and the intermediate frequency LC bandpass filter circuit 500 is connected to the output terminal 700.

[0026] In this embodiment, the RF comb bandpass filter 300 is a 3.7GHz-4.2GHz RF comb bandpass filter. The intermediate frequency LC bandpass filter circuit 500 is a 950MHz-1450MHz intermediate frequency LC bandpass filter. The LDO chip 600 is a 78L06 device.

[0027] In this circuit board structure, the vertically polarized signal access hole 100 and the horizontally polarized signal access hole 110 are used to connect external signals to the RF amplifier circuit. The vertically polarized first-stage RF amplifier circuit 210, the horizontally polarized first-stage RF amplifier circuit 220, and the second-stage RF amplifier circuit 230 constitute a low-noise FET two-stage amplifier circuit. When a signal is connected to the RF amplifier circuit, after passing through the vertically polarized first-stage RF amplifier circuit 210, the horizontally polarized first-stage RF amplifier circuit 220, and the second-stage RF amplifier circuit 230, the gain of the RF signal can be improved, the signal-to-noise ratio can be improved, the circuit signal is more stable, and the signal quality is higher. Furthermore, the signal from the RF amplifier circuit is coupled to the phase-locked loop oscillator circuit 400 after being mixed by a 3.7GHz-4.2GHz RF comb bandpass filter, resulting in a more stable local oscillator signal. In addition, this circuit board structure has a simple circuit, reasonable layout, and high product stability and reliability.

[0028] The 3.7GHz-4.2GHz RF comb bandpass filter is connected to the secondary amplifier circuit 230 and the phase-locked loop oscillator circuit 400, respectively. The signal from the RF amplifier circuit passes through the 3.7GHz-4.2GHz RF comb bandpass filter and then through the phase-locked loop oscillator circuit 400 before being output, making the local oscillator signal more stable.

[0029] In this embodiment, the phase-locked loop (PLL) oscillation circuit 400 includes at least a PLL oscillator, an intermediate frequency (IF) amplifier circuit, a polarization switching circuit, and a power supply circuit for an RF amplifier circuit. The PLL oscillator, IF amplifier circuit, polarization switching circuit, and RF amplifier circuit power supply circuit constitute an integrated circuit, and the PLL oscillator is connected to a crystal oscillator peripheral to this integrated circuit. It is understood that the stability of the local oscillation frequency is crucial in the entire receiving system; parameters such as frequency error and phase noise are critical to signal demodulation. This circuit board structure employs a mixing method between the RF signal and the local oscillation signal within the integrated circuit, ensuring the stability of the local oscillation frequency and reducing the number of components used.

[0030] By designing a phase-locked loop oscillation circuit 400, an RF comb bandpass filter 300, and an intermediate frequency LC bandpass filter circuit 500, the interference signal from 5G mobile phone base stations is resolved by adding a 3.7GHz-4.2GHz RF comb bandpass filter to the RF amplifier circuit and a 950MHz-1450MHz intermediate frequency LC bandpass filter circuit to the intermediate frequency circuit. Specifically, interference signals from 5G mobile phone base stations operate at frequencies between 3.4GHz and 3.6GHz, while the operating input frequency of this circuit board is 3.7GHz to 4.2GHz. The received signal frequency is close to the frequency emitted by the 5G mobile phone base station, potentially causing mutual interference. However, in this circuit board structure, the intermediate frequency (IF) output is 950MHz to 1450MHz. The 3.7GHz-4.2GHz RF comb bandpass filter achieves a -35dB reduction, and the 950MHz-1450MHz IF LC bandpass filter achieves a -15dB reduction. Therefore, it effectively ensures compatibility with 5G base station environments, avoiding the problem of traditional products being unusable in environments with 5G base stations. In other words, the circuit effectively filters out 5G base station signals. Thus, interference from 5G mobile phone base station signals is avoided during reception, resulting in more stable overall reception. It can still operate normally in 5G mobile phone base station environments, ensuring stable operation of the entire circuit board structure in various environments.

[0031] Finally, it should be noted that the above description is only a preferred embodiment of this application and is not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A local oscillator phase-locked loop circuit board structure for suppressing 5G mobile phone interference in the C-band, characterized in that, Includes a circuit board body, on which a signal input, a radio frequency amplifier circuit, a radio frequency comb bandpass filter (300), a phase-locked loop oscillation circuit (400), an intermediate frequency LC bandpass filter circuit (500), an LDO chip (600), and an output terminal (700) are provided. The signal input includes a vertically polarized signal input hole (100) and a horizontally polarized signal input hole (110); The radio frequency amplifier circuit includes a vertically polarized first-stage radio frequency amplifier circuit (210), a horizontally polarized first-stage radio frequency amplifier circuit (220), and a second-stage radio frequency amplifier circuit (230); The vertical polarization signal access port (100) is connected to the vertical polarization first-stage RF amplifier circuit (210), the horizontal polarization signal access port (110) is connected to the horizontal polarization first-stage RF amplifier circuit (220), the vertical polarization first-stage RF amplifier circuit (210) and the horizontal polarization first-stage RF amplifier circuit (220) are respectively connected to the second-stage RF amplifier circuit (230), the second-stage RF amplifier circuit (230) is connected to the RF comb bandpass filter (300), the vertical polarization first-stage RF amplifier circuit (210), the horizontal polarization first-stage RF amplifier circuit (220), the second-stage RF amplifier circuit (230), and the RF comb bandpass filter (300) are respectively connected to the phase-locked loop oscillation circuit (400), and the second-stage RF amplifier circuit (230) is connected to the LDO chip (600). The phase-locked loop oscillation circuit (400) is connected to the intermediate frequency LC bandpass filter circuit (500), and the intermediate frequency LC bandpass filter circuit (500) is connected to the output terminal (700).

2. The local oscillator phase-locked loop circuit board structure for suppressing 5G mobile phone interference in the C-band according to claim 1, characterized in that, The radio frequency comb bandpass filter (300) is a 3.7GHz-4.2GHz radio frequency comb bandpass filter.

3. The local oscillator phase-locked loop circuit board structure for suppressing 5G mobile phone interference in the C-band according to claim 1, characterized in that, The intermediate frequency LC bandpass filter circuit (500) is a 950MHz-1450MHz intermediate frequency LC bandpass filter.

4. The local oscillator phase-locked loop circuit board structure for suppressing 5G mobile phone interference in the C-band according to claim 1, characterized in that, The phase-locked loop oscillation circuit (400) includes at least a phase-locked loop oscillator, an intermediate frequency amplifier circuit, a polarization switching circuit, and a power supply circuit for a radio frequency amplifier circuit. The phase-locked loop oscillator, the intermediate frequency amplifier circuit, the polarization switching circuit, and the power supply circuit for the radio frequency amplifier circuit constitute an integrated circuit, and the phase-locked loop oscillator is connected to a crystal oscillator on the periphery of the integrated circuit.

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