CN203761333U - Filtering circuit, antenna circuit and mobile terminal - Google Patents
Filtering circuit, antenna circuit and mobile terminal Download PDFInfo
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- CN203761333U CN203761333U CN201420082076.9U CN201420082076U CN203761333U CN 203761333 U CN203761333 U CN 203761333U CN 201420082076 U CN201420082076 U CN 201420082076U CN 203761333 U CN203761333 U CN 203761333U
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- filter circuit
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Abstract
The utility model provides a filtering circuit, an antenna circuit and a mobile terminal. The filtering circuit comprises a first capacitor, a second capacitor and an auxiliary filtering element in serial connection with a signal line, wherein the first end of the first capacitor is connected with the first end of the auxiliary filtering element, the first end of the second capacitor is connected with the second end of the auxiliary filtering element, and the second end of the first capacitor and the second end of the second capacitor are connected with different grounded circuits respectively. The first capacitor and the second capacitor in the filter circuit are located in the different grounded circuits; when a high-speed signal passes through the signal line, filtering can be carried out through the two circuits, and accordingly the stray capacitance between the two capacitors can be reduced, and performance of the circuits is be improved.
Description
Technical field
The utility model relates to circuit engineering field, particularly a kind of filter circuit, antenna circuit and mobile terminal.
Background technology
Along with the development of technology, the parasitic capacitance between the each element in integrated circuit also becomes one of principal element affecting performance of integrated circuits.Particularly, in printed circuit board (PCB) (Printedcircuit board, the PCB) wiring of high speed signal, parasitic capacitance can cause immeasurable impact to impedance matching, thereby the performance to circuit and the propagation of signal cause interference.
Parasitic implication is exactly original not in that local design capacitance, but owing to always having mutual appearance between wiring, mutual inductance just look like be colonize between wiring equally, so be parasitic capacitance.Parasitic capacitance generally refers to inductance, resistance, the capacitance characteristic that chip pin etc. show under high frequency situations.In fact, an equivalent resistance is in an electric capacity, an inductance, and the series winding of a resistance, and in low frequency situation, performance is not clearly, and under high frequency situations, equivalence value can increase, and can not ignore.In calculating, we will take into account.ESL is exactly equivalent inductance, and ESR is exactly equivalent resistance.No matter be resistance, electric capacity, inductance, or diode, triode, metal-oxide-semiconductor, also has IC, and the in the situation that of high frequency, we will consider their equivalent capacitance value, inductance value.
In the wiring of Wifi high speed signal, parasitic capacitance is often present between metal and metal.In prior art, Wifi signal carries out filtering through π shape circuit conventionally, thereby improves the impact on parasitic capacitance.Fig. 1 shows the structural representation of the π shape filter circuit in existing printed circuit board (PCB).With reference to figure 1, the region 13 between metal wire 1 and metal wire 3 is the first electric capacity in filter circuit, and the region 23 between metal wire 2 and metal wire 3 is the second electric capacity in filter circuit.In existing π shape filter circuit, two electric capacity are parallel, and are positioned at the same side of metal wire 3.So, between the first electric capacity and the second electric capacity, still have parasitic capacitance and exist.
Therefore the parasitic capacitance, how reducing in circuit just becomes one of those skilled in the art's problem demanding prompt solution with the performance that improves circuit.
Utility model content
The problem that the utility model solves is how effectively to reduce the parasitic capacitance in circuit, thereby improves the performance of circuit.
For addressing the above problem, the utility model provides a kind of filter circuit, comprise: the first electric capacity, the second electric capacity and be serially connected with the auxiliary filter element in holding wire, the first end of described the first electric capacity connects the first end of described auxiliary filter element, and the first end of described the second electric capacity connects the second end of described auxiliary filter element; The second end of described the first electric capacity is connected respectively different grounded circuits with the second end of described the second electric capacity.
Optionally, the both sides of holding wire described in described the first electric capacity and described the second electric capacity apportion.
Optionally, described the first electric capacity and described the second electric capacity are respectively perpendicular to described holding wire setting.
Optionally, described the first electric capacity and described the second electric capacity are all positioned at the same side of described holding wire, and described the first electric capacity and the not parallel setting of described the second electric capacity.
Optionally, described the first electric capacity and vertical setting of described the second electric capacity.
Optionally, described auxiliary filter element is inductance.
Optionally, described auxiliary filter element is resistance.
The utility model also provides a kind of antenna circuit, comprising: the filter circuit described in above-mentioned any one.
Optionally, described antenna circuit is WIFI antenna circuit.
The utility model also provides a kind of mobile terminal, comprises above-mentioned antenna circuit.
Compared with prior art, the technical solution of the utility model has the following advantages:
In filter circuit of the present utility model, the second end of described the first electric capacity is connected respectively different grounded circuits with the second end of the second electric capacity.Like this, when on holding wire when transmit high-speed signals, these two electric capacity are arranged in different grounded circuits, thereby can effectively reduce the parasitic capacitance between these two electric capacity, and then improve the performance of circuit.
Further, in filter circuit of the present utility model, described the first electric capacity and described the second electric capacity can also divide the both sides of column signal line, thereby effectively expand the distance between the first electric capacity and the second electric capacity, and then further reduced the parasitic capacitance between these two electric capacity, and further improve the performance of circuit.
Brief description of the drawings
Fig. 1 is the structural representation of π shape filter circuit in prior art;
Fig. 2 is the structural representation of the embodiment mono-of filter circuit of the present utility model;
Fig. 3 is the schematic equivalent circuit of filter circuit shown in Fig. 2.
Embodiment
As described in the background art, in existing π shape filter circuit, because two electric capacity distances are very near, therefore the second end of these two electric capacity is connected in identical grounded circuit conventionally; And be distributed in the same side of holding wire because these two electric capacity become π shape, therefore, between these two electric capacity, have parasitic capacitance, thereby the performance of circuit is caused to harmful effect.
By formula C=W*L*Eo*Er/d, (W represents trace width, and L represents track lengths, and Eo represents dielectric constant of air, Er represents substrate relative dielectric constant, d represents two distances between PCB) known: larger at d, in the constant situation of other parameter values, the value of C can be less.Therefore, can reduce parasitic capacitance by the mode that increases two distance d between PCB, but this mode can be restricted in integrated circuit.Therefore, in prior art, conventionally the parameter of PCB material and circuit is debugged and controlled, thereby at a high speed to the parasitic capacitance in π shape circuit.But the material that different PCB manufacturers uses is also not quite similar, therefore, to debug for a certain material the circuit setting and cannot be applied directly in other manufacturers, versatility is bad.
The second end of these two electric capacity is connected respectively different grounded circuits by the utility model, like this, in the time that high speed signal transmits via holding wire, can carry out filtering by the electric capacity that is positioned at different circuit, thereby reduce the impact of parasitic capacitance.
Further, the first electric capacity and the second electric capacity can also be arranged at respectively to the both sides of holding wire, so just expand greatly the distance between two electric capacity, thereby further reduced parasitic capacitance.
For above-mentioned purpose of the present utility model, feature and advantage can more be become apparent, below in conjunction with accompanying drawing, specific embodiment of the utility model is described in detail.
For effectively reducing parasitic capacitance to improve the performance of circuit, the utility model provides a kind of filter circuit, comprise: the first electric capacity, the second electric capacity and be serially connected with the auxiliary filter element in holding wire, the first end of described the first electric capacity connects the first end of described auxiliary filter element, and the first end of described the second electric capacity connects the second end of described auxiliary filter element; The second end of described the first electric capacity is connected respectively different grounded circuits with the second end of described the second electric capacity.
In concrete application, described auxiliary filter element can be inductance, can be also resistance; The utility model does not limit this.
Fig. 2 shows the structural representation of the embodiment mono-of filter circuit of the present utility model.With reference to figure 2, in the present embodiment, the region 13 between metal wire 1 and metal wire 3 is the first electric capacity in filter circuit, and the region 43 between metal wire 4 and metal wire 3 is the second electric capacity in filter circuit.It should be noted that, the filter circuit of the present embodiment also comprises auxiliary filter element, as inductance, but also not shown in Fig. 2.
In the present embodiment, metal wire 3(holding wire described in described the first electric capacity and described the second electric capacity apportion) both sides.And described the first electric capacity and described the second electric capacity are respectively perpendicular to described holding wire setting.In the present embodiment, described the first electric capacity is connected respectively different grounded circuits with described the second electric capacity, and metal wire 1 is connected respectively different ground ends with metal wire 4.
Fig. 3 is the schematic equivalent circuit of the filter circuit shown in Fig. 2.With reference to figure 3, inductance L is serially connected with in holding wire (being the metal wire 3 in Fig. 2), the first capacitor C 1, the second capacitor C 2 are arranged at respectively the both sides of holding wire, and described the first capacitor C 1 is connected respectively different grounded circuits with the second capacitor C 2, as shown in Figure 3, the first capacitor C 1 connects ground GND1, and described the second capacitor C 2 connects ground GND2.
In the present embodiment, the distance between two electric capacity that the distance between described the first electric capacity and described the second electric capacity is arranged than π shape in prior art is much bigger, therefore, has effectively reduced the parasitic capacitance between described the first electric capacity and described the second electric capacity.In addition, because described the first electric capacity is connected respectively different grounded circuits with described the second electric capacity, therefore, in the time that high speed signal transmits by metal wire (holding wire) 3, can carry out filtering by two different loops, thereby further reduce the impact of parasitic capacitance on circuit performance.
It should be noted that, in other embodiments, described the first electric capacity and described the second electric capacity can also be positioned at the same side of described holding wire simultaneously, and described the first electric capacity and the not parallel setting of described the second electric capacity.For example, described the first electric capacity can vertically arrange with described the second electric capacity.
By after described the first electric capacity and not parallel setting of described the second electric capacity, can increase the distance between described the first electric capacity and described the second electric capacity, according to aforementioned described, can be learnt by formula C=W*L*Eo*Er/d, in the situation that other parameter values are constant, distance d between electric capacity is larger, and the value of parasitic capacitance C can be less.Like this, just can effectively reduce parasitic capacitance in circuit, thereby improve the performance of circuit.
Correspondingly, the utility model also provides a kind of antenna circuit that comprises aforementioned filter circuit.Described antenna circuit can be WIFI antenna circuit.Certainly, the utility model does not limit this, and the antenna circuit of other types also can adopt above-mentioned filter circuit to reduce the parasitic capacitance in circuit.
The utility model also provides a kind of mobile terminal that comprises above-mentioned antenna traces, and described mobile terminal can be the mobile devices such as mobile phone, panel computer.
Although the utility model discloses as above, the utility model is not defined in this.Any those skilled in the art, not departing from spirit and scope of the present utility model, all can make various changes or modifications, and therefore protection range of the present utility model should be as the criterion with claim limited range.
Claims (10)
1. a filter circuit, it is characterized in that, comprise: the first electric capacity, the second electric capacity and be serially connected with the auxiliary filter element in holding wire, the first end of described the first electric capacity connects the first end of described auxiliary filter element, and the first end of described the second electric capacity connects the second end of described auxiliary filter element; The second end of described the first electric capacity is connected respectively different grounded circuits with the second end of described the second electric capacity.
2. filter circuit as claimed in claim 1, is characterized in that, the both sides of holding wire described in described the first electric capacity and described the second electric capacity apportion.
3. filter circuit as claimed in claim 1 or 2, is characterized in that, described the first electric capacity and described the second electric capacity are respectively perpendicular to described holding wire setting.
4. filter circuit as claimed in claim 1, is characterized in that, described the first electric capacity and described the second electric capacity are all positioned at the same side of described holding wire, and described the first electric capacity and the not parallel setting of described the second electric capacity.
5. filter circuit as claimed in claim 4, is characterized in that, described the first electric capacity and vertical setting of described the second electric capacity.
6. filter circuit as claimed in claim 1, is characterized in that, described auxiliary filter element is inductance.
7. filter circuit as claimed in claim 1, is characterized in that, described auxiliary filter element is resistance.
8. an antenna circuit, is characterized in that, comprising: the filter circuit as described in claim 1～7 any one.
9. antenna circuit as claimed in claim 8, is characterized in that, described antenna circuit is WIFI antenna circuit.
10. a mobile terminal, is characterized in that, comprises antenna circuit as claimed in claim 8 or 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420082076.9U CN203761333U (en) | 2014-02-25 | 2014-02-25 | Filtering circuit, antenna circuit and mobile terminal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420082076.9U CN203761333U (en) | 2014-02-25 | 2014-02-25 | Filtering circuit, antenna circuit and mobile terminal |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203761333U true CN203761333U (en) | 2014-08-06 |
Family
ID=51256564
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201420082076.9U Expired - Fee Related CN203761333U (en) | 2014-02-25 | 2014-02-25 | Filtering circuit, antenna circuit and mobile terminal |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN203761333U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2022001891A1 (en) * | 2020-06-28 | 2022-01-06 | 浙江涂鸦智能电子有限公司 | Light board structure and light fixture having same |
-
2014
- 2014-02-25 CN CN201420082076.9U patent/CN203761333U/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2022001891A1 (en) * | 2020-06-28 | 2022-01-06 | 浙江涂鸦智能电子有限公司 | Light board structure and light fixture having same |
| US11774079B1 (en) | 2020-06-28 | 2023-10-03 | Hangzhou Tuya Information Technology Co., Ltd. | Light board structure and light fixture having the same |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20140806 Termination date: 20190225 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |