CN113114382A

CN113114382A - Power supply filtering device

Info

Publication number: CN113114382A
Application number: CN202010050841.9A
Authority: CN
Inventors: 陈亮; 武小元; 沈婷婷
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2020-01-13
Filing date: 2020-01-13
Publication date: 2021-07-13
Anticipated expiration: 2040-01-13
Also published as: CN113114382B

Abstract

The embodiment of the application discloses device of power filtering, the device includes: the PCB comprises a first copper foil wire and one or more copper sheets laid on the PCB, wherein the one or more copper sheets are connected with a power supply pin on the PCB through the first copper foil wire; the one or more copper sheets and the first copper foil wire are used for filtering signals in a target frequency range from the power signals of the power pins, the target frequency range can be determined based on the area of each copper sheet in the one or more copper sheets and the length and width of the first copper foil wire, and the power pins on the PCB are power pins of the BOSA RX and used for providing the power signals for the BOSA RX. By adopting the embodiment of the application, the interference of the 5G WiFi signal to the BOSA power supply signal can be effectively reduced, and the anti-interference capability of the BOSA is improved.

Description

Power supply filtering device

Technical Field

The application relates to the technical field of electronics, in particular to a power supply filtering device.

Background

A Passive Optical Network (PON) system generally includes an Optical Line Terminal (OLT) device located at a local side, an Optical Network Terminal (ONT) device located at a user side, and an optical distribution network (ODU) connecting the two devices. The ONT device is usually deployed in a user's home, and mainly has an optical interface and a wireless local area network (WiFi) interface; the optical interface is used for connecting with an operator local side device (OLT), and the WiFi interface is used for connecting with a user terminal.

Currently, an optical interface on an ONT is in a form of a Board On Board (BOB) of an optical device, and a receiving end (RX) of a bi-directional optical sub-assembly (BOSA) in the ONT is directly inserted into an Optical Network Unit (ONU) board. The RX of the BOSA includes 5 pins, which are 2 pins for receiving 10G PON signals, 2 pins for receiving power signals, and 1 ground pin. The WiFi antenna of the ONT has two forms of a rod and a patch, and as the ONT equipment becomes smaller, the WiFi antenna of the ONU tends to the patch form more, and the distance between the patch type WiFi antenna positioned in the ONT shell and the ONU single plate is reduced. However, the power supplies of BOSA (TIA and APD power supplies) are sensitive to interference sources, mainly to 5G WiFi signals. Therefore, when the WiFi antenna inside the ONT housing radiates a WiFi signal at a 5G frequency point to the outside, the 5G WiFi signal will cause interference to a power supply signal of the BOSA, and the sensitivity of the BOSA for receiving a 10G PON signal is affected.

Disclosure of Invention

The embodiment of the application provides a device of power filtering, can effectively reduce 5G wiFi signal to BOSA power signal's interference, promotes BOSA's interference killing feature.

In a first aspect, an embodiment of the present application provides a device for power filtering, where the device includes a first copper foil wire laid on a PCB and one or more copper sheets, and the one or more copper sheets are connected to a power pin on the PCB through the first copper foil wire. Wherein the power filtering device is configured to filter out a signal (herein, a high-frequency interference signal) in a target frequency range from the power signal of the power pin, and the target frequency range may be determined based on an area of each of the one or more copper sheets and a length and a width of the first copper foil wire. The first copper foil wire comprises a copper foil wire between each copper sheet of the one or more copper sheets and the power supply pin on the PCB. The PCB is an ONU single board, and a power supply pin on the PCB is a power supply pin of the BOSA RX and is used for providing a power supply signal for the BOSA RX. Each of the one or more copper sheets exhibits a capacitive characteristic, equivalent to a capacitance; the first copper foil wire has inductance characteristic and is equivalent to an inductor.

The device for power filtering is designed on the PCB by utilizing the capacitance characteristic of the copper sheet and the inductance characteristic of the copper foil wire, the interference of the 5G WiFi signal on the BOSA power signal is reduced through the filtering characteristic of the device, and the anti-interference capability of the BOSA is improved.

With reference to the first aspect, in a possible implementation manner, the PCB is a multi-layer board, and includes at least two PCB layers, and the one or more copper sheets may be laid on different PCB layers. Specifically, the one or more copper sheets include one or more first copper sheets and one or more second copper sheets, the first copper sheets may be located on the same PCB layer as the power pins on the PCB, and the second copper sheets may be located on different PCB layers from the power pins on the PCB, that is, the first copper sheets and the second copper sheets are located on different PCB layers. The first copper sheet can pass through the copper foil line with the power pin on this PCB and be connected, and the second copper sheet can pass through copper foil line and metallization via hole with the power pin on this PCB and be connected. Metallized vias are used to establish a connection between two different PCB layers. The first copper foil wire comprises a copper foil wire between a first copper sheet and the power supply pin on the PCB and a copper foil wire between a second copper sheet and the power supply pin on the PCB.

According to the embodiment of the application, the copper sheets are laid on different PCB layers in a space folding mode and are connected through the drill holes, so that the size of the power supply filtering device can be reduced.

With reference to the first aspect, in one possible implementation, the one or more copper sheets may be applied to the same PCB layer of the PCB. The minimum frequency in the target frequency range is determined based on the inductance value of the first copper foil wire, and the maximum frequency is determined based on the smallest capacitance value in the capacitance values of the copper sheets. The inductance value of the first copper foil wire is determined based on the length and the width of the first copper foil wire, and the capacitance value of the copper sheet is determined based on the area of the copper sheet, the dielectric constant of the PCB and the distance between the laid layer of the copper sheet and the adjacent PCB layer.

With reference to the first aspect, in one possible implementation, the one or more copper sheets may be applied to the same PCB layer of the PCB. The minimum frequency in the target frequency range is determined based on the inductance value of the first copper foil wire, and the maximum frequency is determined based on the smallest capacitance value in the capacitance values of the copper sheets. The inductance value of the first copper foil wire is determined based on the length and the width of the first copper foil wire, and the capacitance value of the copper sheet is determined based on the area of the copper sheet, the dielectric constant of the PCB and the distance between the laid layer of the copper sheet and the adjacent PCB layer laid with another copper sheet in the one or more copper sheets.

With reference to the first aspect, in one possible implementation manner, the capacitance value of each copper sheet is 0.1 to 100pF, and the inductance value of the first copper foil line is 0.1 to 10 nH.

With reference to the first aspect, in one possible implementation, the target frequency range is 3GHz to 10 GHz.

In a second aspect, an embodiment of the present application provides an electronic device, which includes the apparatus in any one of the possible implementation manners of the first aspect.

By implementing the embodiment of the application, the interference of the 5G WiFi signal to the BOSA power supply signal can be effectively reduced, and the anti-interference capability of the BOSA is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings used in the description of the embodiments will be briefly introduced below.

Fig. 1 is a schematic diagram of a conventional power supply filtering apparatus according to an embodiment of the present application;

FIG. 2 is a schematic diagram of an equivalent circuit of an apparatus for power filtering according to an embodiment of the present disclosure;

FIG. 3 is a diagram illustrating simulation results of an apparatus for power filtering according to an embodiment of the present disclosure;

fig. 4 is a schematic structural diagram of an apparatus for power filtering according to an embodiment of the present application;

FIG. 5 is a schematic structural diagram of an apparatus for power filtering according to an embodiment of the present disclosure;

FIG. 6 is a schematic diagram of another structure of an apparatus for power filtering according to an embodiment of the present disclosure;

fig. 7 is a schematic structural diagram of an electronic device provided in an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application.

In the embodiment of the present application, the filter is a frequency selection device, which can pass a specific frequency component in a signal and greatly attenuate other frequency components. That is, signals useful for the apparatus are passed through with as little loss as possible, and signals not useful for the apparatus are filtered out as much as possible. In other words, the filter (filter) can effectively filter the frequency point of the specific frequency or frequencies other than the frequency point to obtain a power signal of the specific frequency or eliminate the power signal of the specific frequency. The filter is divided into four types of low-pass, high-pass, band-pass and band-stop filters according to the frequency band of the signal passed by the filter. The low pass filter allows low frequency or direct current components in the signal to pass through, suppressing high frequency components or interference or noise. The high pass filter allows high frequency components in the signal to pass and suppresses low frequency or dc components. The band pass filter allows signals in a certain frequency band to pass through, and suppresses signals, interference or noise below or above the frequency band. The band-stop filter suppresses signals within a certain frequency band and allows signals outside the frequency band to pass.

Referring to fig. 1, fig. 1 is a schematic diagram of a conventional power supply filtering apparatus according to an embodiment of the present application. As shown in fig. 1, the BOSA RX part adopts a scheme of directly plugging an ONU single board, a power PIN (or a power PIN) of the BOSA RX part is directly soldered to a Printed Circuit Board (PCB), and a proper magnetic bead LB and a capacitor C are arranged on the BOSA RX power PIN of the PCB, so as to form a low pass filter for filtering a 5G frequency point signal on the BOSA RX power PIN. However, the frequency of the 5G frequency point signal is high, and in the scheme of forming the low-pass filter by the magnetic bead LB and the capacitor C, the required filtering capacitance value is small (pico-farad pF level), the capacitance radius of the pF level is limited, and the filter needs to be arranged near the power supply pin of the BOSA RX. Due to the fact that the over-wave soldering temperature on the PCB is high, the single board on the periphery of the over-wave soldering on the PCB deforms, components are not prone to being arranged, and therefore a distribution forbidding area needs to be set during over-wave soldering, and the magnetic beads LB and the capacitor C need to be arranged outside the distribution forbidding area (for example, 5 mm) of the BOSA RX power supply pin. Therefore, the low-pass filter formed by the magnetic beads LB and the capacitor C has a limited ability to filter the high-frequency spot signal.

In some possible embodiments, the BOSA RX part may also be manually welded with the ONU single board by using a flexible board. Due to the fact that the forbidden region of the manual welding mode is small, magnetic beads and capacitors can be arranged near the BOSA RX power supply pin on the soft board to form a low-pass filter used for filtering 5G frequency point signals on the BOSA RX power supply pin. But the BOSA and the ONU veneer are connected by the soft board, so that the material cost and the processing cost of the magnetic beads and the capacitor are increased.

This application provides a power filtering's device in order to solve filtering effect and the incompatible problem of cost on BOSA RX power pin, can effectively reduce 5G wiFi signal to BOSA power signal's interference in reduce cost, promotes BOSA's interference killing feature.

Since BOSA RX has 2 pins to receive power signals, BOSA RX has 2 power signals. For ease of description, filtering is performed below for any of the BOSA RX power signals. Optionally, the power supply filtering device provided by the present application may be applicable to any one of the two paths of power signals in the BOSA RX, and may also be applicable to two paths of power signals in the BOSA RX.

Referring to fig. 2, fig. 2 is a schematic diagram of an equivalent circuit of the apparatus for filtering power provided by the embodiment of the present application. As shown in fig. 2, the equivalent circuit includes 2 capacitors C1 and C2, 1 inductor L, and 1 resistor R. One end of the capacitor C1 is connected to one end of the inductor L, and the other end is grounded. The other end of the inductor L is connected with one end of the resistor R. The other end of the resistor R is connected with one end of the capacitor C2 and a power supply pin of the BOSA RX. The other terminal of the capacitor C2 is connected to ground. Because the capacitor has the function of passing high frequency and low frequency, and the inductor has the function of passing low frequency and high frequency, the equivalent circuit can form a power supply filtering device for inhibiting signals in a section of frequency in the power supply signal of the BOSA RX power supply pin from passing. In the equivalent circuit, after a power supply signal input by a power supply is filtered by a capacitor C1, an inductor L, a resistor R and a capacitor C2, a purer power supply signal can be obtained and input into a power supply pin of a BOSA RX, and the purer power supply signal is provided for the BOSA, so that the interference of a 5G WiFi signal to the BOSA power supply signal is reduced.

Because the working frequency range of the 5G WiFi signal is 5.15 GHz-5.85 GHz, the equivalent circuit can inhibit the signals with the frequency range of 5.15 GHz-5.85 GHz from passing through. In practical applications, the frequency range of the equivalent circuit rejection signal may include an operating frequency range of a 5G WiFi signal, for example, the frequency range of the equivalent circuit rejection signal is 3GHz to 10 GHz. Optionally, the frequency range of the equivalent circuit suppression signal can be flexibly adjusted according to the capacitance value and the inductance value. It will be appreciated that fig. 2 is merely exemplary showing 2 capacitors, and in practical applications, the equivalent circuit may include 1 capacitor. It will also be appreciated that the resistor R in series with the inductor L in fig. 2 prevents the inductor L from being burned out due to short circuiting.

According to the embodiment of the application, the band elimination filter is formed by connecting the capacitor and the inductor in parallel, so that the signal in one section of frequency is inhibited from passing through, the 5G frequency point signal in the power signal of the input BOSA is inhibited, the interference of the 5G WiFi signal on the power signal of the BOSA is reduced, and the anti-interference capacity of the BOSA is improved.

In some possible embodiments, the copper foil wires, copper sheets, and drilled holes laid on the PCB have both capacitive and inductive characteristics for high frequency signals. The size (e.g., length and width) of the copper foil wire determines the inductance or capacitance characteristics of the copper foil wire, and the size (e.g., area) of the copper sheet also determines the inductance or capacitance characteristics of the copper sheet. Because the copper foil wire has resistance, the copper foil wire also has resistance effect. The PCB in the embodiment of the application is a multilayer board, namely, the PCB is provided with a plurality of circuit board layers. On a rigid PCB, there is a dielectric layer between the stack-up of multiple circuit board layers. A commonly used dielectric layer material is FR4 material. The dielectric constant of the dielectric layer on the PCB is usually 4.4 + -10%.

According to the embodiment of the application, the power filtering device is designed on the PCB by utilizing the capacitance characteristic of the copper sheet and the inductance characteristic of the copper foil wire, and the interference of the 5G WiFi signal on the BOSA power signal is reduced through the filtering characteristic of the power filtering device. Specifically, the device for power supply filtering in the embodiment of the present application includes a first copper foil wire laid on the PCB and one or more copper sheets, where the one or more copper sheets are connected to a power supply pin on the PCB through the first copper foil wire. The power supply filtering device is used for filtering out signals (herein, high-frequency interference signals) in a target frequency range from the power supply signals of the power supply pins, and the target frequency range can be determined based on the area of each copper sheet in the one or more copper sheets and the length and width of the first copper foil wire. The first copper foil wire comprises a copper foil wire between each copper sheet of the one or more copper sheets and the power supply pin on the PCB. The PCB is an ONU single board, and a power supply pin on the PCB is a power supply pin of a BOSA RX and is used for providing a power supply signal for the BOSA. Each of the one or more copper sheets exhibits a capacitive characteristic, equivalent to a capacitance; the first copper foil wire presents inductance characteristic and is equivalent to an inductor; because the first copper foil wire has resistance effect, the first copper foil wire can also be equivalent to resistance.

In some possible embodiments, adjusting the area of the copper sheet is equivalent to adjusting an equivalent capacitance value of the copper sheet, and the equivalent capacitance value of the copper sheet satisfies the formula (1-1):

C＝ε*S/D， (1-1)

c in the formula (1-1) represents the equivalent capacitance value of the copper sheet, epsilon represents the dielectric permittivity of the dielectric layer of the PCB, and S is the area of the copper sheet.

Alternatively, if one or more copper sheets are laid down on the same PCB layer (or the same circuit board layer) of the PCB, D represents the distance between the laid down layer of the copper sheet and its adjacent PCB layer. For example, the PCB has 4 layers, and assuming that the copper sheets are all laid on the first layer of the PCB, D represents the distance between the first layer and the second layer of the PCB. If one or more copper sheetsLaid on different PCB layers (or different circuit board layers) of the PCB, then D may be: (1) if the laying layer where the copper sheet a is located in one or more copper sheets has an adjacent PCB layer, D represents the distance between the laying layer of the copper sheet a and the adjacent PCB layer where another copper sheet in one or more copper sheets is located when the equivalent capacitance value of the copper sheet a is calculated. For example, the PCB has 4 layers, and assuming that one or more copper sheets are laid on each of the first layer, the third layer and the fourth layer of the PCB, when calculating the equivalent capacitance value of the copper sheet a on the first layer of the PCB, D represents the distance between the first layer and the third layer of the PCB. (2) If the laying layer of the copper sheet b in one or more copper sheets has two adjacent PCB layers, D is (D) when the equivalent capacitance value of the copper sheet b of the jth layer on the PCB is calculated_ij+D_jk)/(D_ij*D_jk). Wherein D is_ijDenotes the distance between the ith and jth layers of the PCB, D_jkRepresenting the distance between the jth and kth layers of the PCB. Copper sheets are laid on the ith layer and the kth layer of the PCB, and the ith layer and the kth layer are adjacent PCB layers of the jth layer. For example, assuming that the first layer, the third layer and the fourth layer of the PCB are all laid with one or more copper sheets, when calculating the equivalent capacitance value of the copper sheet b on the third layer of the PCB, the first layer and the fourth layer are all adjacent PCB layers of the third layer, and the value of D is (D)₁₃+D₃₄)/(D₁₃*D₃₄)。

In other possible embodiments, adjusting the length and the width of the copper foil wire is equivalent to adjusting an equivalent inductance value of the copper foil wire, and the equivalent inductance value of the copper foil wire satisfies the formula (1-2):

L＝2*l*(In(21/W)+0.5+0.2235*W/l)， (1-2)

wherein L in the formula (1-2) represents the equivalent inductance value of the copper foil wire, L represents the length of the copper foil wire, and W represents the width of the copper foil wire. In (x) represents the logarithm of the base e

In other possible embodiments, adjusting the length and the width of the copper foil line is also equivalent to adjusting the equivalent resistance value of the copper foil line, and the equivalent resistance value of the copper foil line satisfies the formula (1-3):

R＝ρl/s， (1-3)

wherein, R in the formula (1-3) represents the equivalent resistance value of the copper foil wire, ρ represents the conductivity of the wire (the wire herein refers to the copper foil wire), l represents the length of the copper foil wire, and s represents the cross-sectional area of the copper foil wire.

Because the equivalent capacitance value of the copper sheet meets the formula (1-1) and the equivalent inductance value of the copper foil wire meets the formula (1-2), a proper equivalent capacitance value can be obtained by adjusting the area of the copper sheet, and a proper equivalent inductance value can be obtained by adjusting the length and the width of the copper foil wire, so that the frequency range (namely the target frequency range) of the signal filtered from the power signal of the power pin by the power filtering device is determined through the equivalent capacitance value and the equivalent inductance value.

It is understood that the minimum frequency in the target frequency range is determined based on the inductance value of the first copper foil line, and the maximum frequency is determined based on the smallest capacitance value among the capacitance values of the respective copper sheets. In practical applications, the minimum frequency and the maximum frequency in the target frequency range may be determined based on simulation results. As shown in fig. 3, fig. 3 is a simulation result diagram of the apparatus for power supply filtering according to the embodiment of the present application. As shown in fig. 3, the abscissa of fig. 3 represents frequency and the ordinate represents attenuation on the BOSA RX power pin. Assuming that a power supply filtering device is placed on each of two power supply pins of the BOSA RX, the dielectric constant epsilon of the dielectric of the PCB is 4.4, the power supply filtering device comprises 2 copper sheets, the area of the copper sheet 1 is 2.5mm x 2.5mm, and the area of the copper sheet 2 is 5mm x 5 mm. Fig. 3 shows the attenuation on the two power pins (power pin 1 and power pin 2) of the BOSA RX, respectively, and it can be seen from fig. 3 that the power filtering apparatus can achieve an attenuation of-20 dB (decibel) in the range of 3GHz to 10 GHz.

In some possible embodiments, in order to filter the 5G frequency point signal from the power signal of the power pin, the equivalent capacitance of each copper sheet is 0.1 to 100pF, and the inductance of the first copper foil wire is 0.1 to 100nH (nanohenries). The target frequency range may include an operating frequency range of 5G WiFi signals from 5.15GHz to 5.85GHz, and the target frequency range may be from 3GHz to 10 GHz.

In an alternative embodiment, referring to fig. 4, fig. 4 is a schematic structural diagram of the apparatus for power supply filtering provided by the embodiment of the present application. As shown in FIG. 4, the device for filtering the power supply comprises a copper sheet 1 laid on the PCB, a copper sheet 2, …, and n copper sheets of the copper sheet, wherein the n copper sheets are connected with the power supply pins on the PCB through copper foil wires and are equivalent to a band-stop filter. The n copper sheets and the copper foil wires are laid on the same PCB layer (or the same circuit board layer) of the PCB. The power pin on the PCB is a power pin of the BOSA RX and is used for providing a power signal for the BOSA. The power signal of power input passes through the copper foil line and n copper sheets and filters the high frequency signal in this power signal to obtain the power pin of purer power signal input BOSA RX, thereby reduce the interference of 5G frequency point signal to BOSA power signal. It is understood that fig. 4 only shows the position relationship and the shape of the copper sheet, the copper foil wire and the power supply pin by way of example, and in practical application, the shape of the copper sheet laid on the PCB may be any shape, and is not limited to a rectangle; the copper sheets laid on the PCB may have the same orientation (the copper sheets are laid on the upper half board of the PCB as shown in fig. 4) or different orientations (the copper sheets are laid on the upper half board and the lower half board of the PCB).

In another alternative embodiment, the position of the copper sheet laid on the PCB may be in different orientations, referring to fig. 5, fig. 5 is another structural schematic diagram of the apparatus for power filtering provided by the embodiment of the present application. As shown in fig. 5, the power filtering device includes a copper sheet 1, a copper sheet 2 and a first copper foil wire laid on the PCB, the copper sheet 1 is connected to a power pin on the PCB through the copper foil wire, the copper sheet 2 is also connected to the power pin on the PCB through the copper foil wire, and the first copper foil wire includes the copper foil wire between the copper sheet 1 and the power pin and the copper foil wire between the copper sheet 2 and the power pin. Copper sheet 1, copper sheet 2 and first copper foil line lay in the same PCB layer (same circuit board layer) of PCB, and copper sheet 1, copper sheet 2 and the power pin on the PCB are in same PCB layer. The copper sheet 1 is equivalent to a first capacitor, the copper sheet 2 is equivalent to a second capacitor, the first copper foil wire is equivalent to an inductor, and a circuit of the band-elimination filter is formed among the first capacitor, the second capacitor and the inductor. The capacitance value of the first capacitor (i.e. the equivalent capacitance of the copper sheet 1) can be determined based on the area of the copper sheet 1, the dielectric permittivity between the laid layer on which the copper sheet 1 is located and the layer below it (i.e. the dielectric permittivity of the dielectric layer in fig. 5), and the distance between the laid layer on which the copper sheet 1 is located and the adjacent PCB layer (i.e. the adjacent layer (ground) in fig. 5). The capacitance value of the second capacitor (i.e. the equivalent capacitance of the copper sheet 2) may be determined based on the area of the copper sheet 2, the dielectric permittivity between the laid layer on which the copper sheet 2 is located and the layer below it (i.e. the dielectric permittivity of the dielectric layer in fig. 5), and the distance between the laid layer on which the copper sheet 2 is located and the adjacent PCB layer (i.e. the adjacent layer (ground) in fig. 5). The inductance value of the inductor (i.e., the equivalent inductance of the first copper foil wire) may be determined based on the length and width of the first copper foil wire. Optionally, the PCB is an ONU single board, and a power pin on the PCB is a power pin of the BOSA RX, and is configured to provide a power signal to the BOSA. The power signal of power input gets the power pin of purer power signal input BOSA RX through the signal in this first copper foil line, copper sheet 1 and the copper sheet 2 filtering certain frequency to realize reducing 5G wiFi signal to BOSA power signal's interference, promote BOSA's interference killing feature. It can be understood that the shapes of the copper sheets 1 and 2 can be any shapes.

According to the embodiment of the application, the copper sheets and the copper foil wires are laid on the PCB, the cost is not increased, the cost is reduced, the manufacturing process is shortened, the interference of 5G WiFi signals to BOSA power signals is reduced by utilizing the capacitance characteristics of the copper sheets and the inductance characteristics of the copper foil wires, and the anti-interference capacity of the BOSA is improved.

In yet another alternative embodiment, a plurality of copper sheets may be laid on different PCB layers, see fig. 6, and fig. 6 is a schematic view of another structure of the apparatus for power filtering provided by the embodiment of the present application. As shown in fig. 6, the power supply filtering device includes a copper sheet 1, a copper sheet 2 and a first copper foil wire laid on a PCB, the copper sheet 1 and a power supply pin on the PCB are located on the same PCB layer, the copper sheet 2 and the power supply pin on the PCB are located on different PCB layers, that is, the copper sheet 1 and the copper sheet 2 are located on different PCB layers. Copper sheet 1 passes through the copper foil line with the power pin on the PCB and is connected, and copper sheet 2 passes through the copper foil line with the power pin on the PCB and metallizes the via hole and is connected. Metallized vias are used to establish a connection between two different PCB layers. The first copper foil wire comprises a copper foil wire between the copper sheet 1 and a power pin on the PCB and a copper foil wire between the copper sheet 2 and the power pin on the PCB. The copper sheet 1 and the copper sheet 2 have capacitance characteristics and are equivalent to a capacitor; the first copper foil wire has inductance characteristic and is equivalent to an inductor. Optionally, the PCB is an ONU single board, and a power pin on the PCB is a power pin of the BOSA RX, and is configured to provide a power signal to the BOSA. The power signal of power input gets the power pin of purer power signal input BOSA RX through the signal in this first copper foil line, metallized via hole, copper sheet 1 and the copper sheet 2 filtering certain frequency to realize reducing 5G wiFi signal to BOSA power signal's interference, promote BOSA's interference killing feature. It can be understood that the shapes of the copper sheets 1 and 2 can be any shapes.

In some possible embodiments, the copper sheets 1 and 2 may be located at opposite positions of different PCB layers, i.e. the positions where the copper sheets 1 and 2 are vertically mapped onto the same PCB layer overlap.

Referring to fig. 7, fig. 7 is a schematic structural diagram of an electronic device provided in an embodiment of the present application. As shown in fig. 7, the electronic device 100 includes the apparatus for power filtering provided in the embodiment of the present application, where the apparatus for power filtering includes a first copper foil wire laid on a PCB and one or more copper sheets connected to a power pin on the PCB through the first copper foil wire. The one or more copper sheets exhibit capacitive characteristics, equivalent to capacitance; the first copper foil wire has inductance characteristic and is equivalent to an inductor. The device is used for filtering out signals (herein, high-frequency interference signals) in a target frequency range from the power signals of the power pins, wherein the target frequency range can be determined based on the area of each copper sheet in the one or more copper sheets and the length and width of the first copper foil wire. The first copper foil wire comprises a copper foil wire between each copper sheet of the one or more copper sheets and the power supply pin on the PCB. The PCB is an ONU single board, and a power supply pin on the PCB is a power supply pin of the BOSA RX and is used for providing a power supply signal for the BOSA RX.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A power supply filtering device, comprising a first copper foil wire and one or more copper sheets laid on a printed circuit board PCB, wherein:

the one or more copper sheets are connected with a power supply pin on the PCB through the first copper foil line, the one or more copper sheets and the first copper foil line are used for filtering signals in a target frequency range from power supply signals of the power supply pin, and the target frequency range is determined based on the area of each copper sheet in the one or more copper sheets and the width and length of the first copper foil line.

2. The apparatus of claim 1, wherein the PCB comprises at least two PCB layers, the one or more copper sheets comprise one or more first copper sheets and one or more second copper sheets, the first copper sheets are located on the same PCB layer as the power pins on the PCB, the second copper sheets are located on a different PCB layer from the power pins on the PCB, and the second copper sheets are connected to the power pins through copper foil wires and metalized vias;

the first copper foil wire comprises a copper foil wire between the first copper sheet and the power supply pin on the PCB and a copper foil wire between the second copper sheet and the power supply pin on the PCB.

3. The apparatus of claim 1, wherein the one or more copper sheets are laid on a same PCB layer of the PCB, a minimum frequency in the target frequency range is determined based on an inductance value of the first copper foil wire, and a maximum frequency is determined based on a smallest capacitance value among capacitance values of the respective copper sheets;

the inductance value of the first copper foil wire is determined based on the width and the length of the first copper foil wire, and the capacitance value of the copper sheet is determined based on the area of the copper sheet, the dielectric permittivity of the PCB and the distance between the laid layer of the copper sheet and the adjacent PCB layer.

4. The apparatus of claim 1, wherein a minimum frequency in the target frequency range is determined based on an inductance value of the first copper foil wire and a maximum frequency is determined based on a smallest capacitance value among capacitance values of the respective copper sheets;

the inductance value of the first copper foil wire is determined based on the width and the length of the first copper foil wire, and the capacitance value of the copper sheet is determined based on the area of the copper sheet, the dielectric permittivity of the PCB and the distance between a laid layer of the copper sheet and an adjacent PCB layer laid with another copper sheet in the one or more copper sheets.

5. The device of claim 3 or 4, wherein the capacitance value of each copper sheet is 0.1-100 pF, and the inductance value of the first copper foil line is 0.1-10 nH.

6. The apparatus according to any one of claims 1-5, wherein the PCB is an ONU (optical network unit) board, and the power pin on the PCB is a power pin of a BOSA (optical transmit receive assembly).

7. The apparatus of any one of claims 1-6, wherein the target frequency range is 3GHz to 10 GHz.

8. An electronic device, characterized in that it comprises an apparatus according to any one of claims 1 to 7.