CN100347954C - Switchable high-frequency band filter - Google Patents
Switchable high-frequency band filter Download PDFInfo
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- CN100347954C CN100347954C CNB031241050A CN03124105A CN100347954C CN 100347954 C CN100347954 C CN 100347954C CN B031241050 A CNB031241050 A CN B031241050A CN 03124105 A CN03124105 A CN 03124105A CN 100347954 C CN100347954 C CN 100347954C
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Abstract
The present invention relates to a switchable high-frequency band filter which comprises an input node, an output node, a switchable LC resonator and a switching signal input interface circuit, wherein the switchable LC resonator is coupled between the input node and the output node, and is used for providing a plurality of switchable filter transformation functions for a plurality of high-frequency signals which have different frequencies and are conveyed between the input node and the output node. The switching signal input interface circuit is coupled with the switchable LC resonator. The switching signal is applied to the switchable LC resonator by the switching signal input interface circuit, and is used for controlling the switchable LC resonator to provide an appropriate function of the switchable filter transformation functions for the high-frequency signals with different frequencies.
Description
Technical field
The present invention relates to a kind of high freguency bandpass filter.The present invention be more particularly directed to a kind of switchable high freguency bandpass filter, be applied in the high frequency communication technique field, can provide different filter transform functions respectively the high-frequency signal of two different frequencies.
Background technology
In the high frequency communication technique field of today,, developed multiple frequency communication electronic product, for example dual-band mobile phone or multi-frequency mobile phone in order to increase the spectral range that can be used for communication.Typically, use in the communication electronic product in multiple frequency, must be respectively at the suitable composition assembly circuit of each operating frequency design, to answer the particular demands of each operating frequency.As a result, cause multiple frequency too much, not only hindered the size of high frequency communication system to dwindle, also improve production cost with the number of the composition assembly circuit in the communication electronic product.
In order to reduce the size of multiple frequency, expect that each operating frequency can share identical composition assembly circuit, to reduce the number of necessary composition assembly with the communication electronic product.Yet each high-frequency characteristic of forming assembly circuit is neither identical, so be difficult to be applied to each operating frequency.In other words, if each service frequency signal is shared identical composition assembly circuit, then may suffer from the problem that interferes with each other between the signal of each operating frequency.
For example, high freguency bandpass filter is applied in the high frequency communication system often, in order to carry out the function that frequency is selected.Use in the communication electronic product in multiple frequency, for the function that each operating frequency is provided best frequency select, must provide different filter transform functions respectively with high-frequency signal at the high freguency bandpass filter of each operating frequency design specialized to different frequency.Yet as previously mentioned, this mode has not only hindered multiple frequency to dwindle with the size of communication electronic product, also improves its production cost.
Summary of the invention
Because foregoing problems, one object of the present invention is to provide a kind of switchable high freguency bandpass filter, can provide two kinds of different filter transform functions to give two kinds of different high-frequency signals, improving the frequency selective power, and reduce the interference between each frequency signal.
Another object of the present invention is to provide a kind of switchable high freguency bandpass filter, can provide two kinds of different filter transform functions to give two kinds of different high-frequency signals, reducing the number of the necessary composition electronic building brick that is associated with high freguency bandpass filter, and minification and reducing production costs.
According to an embodiment of the present invention, a kind of switchable high freguency bandpass filter is provided, comprising: an input node and an output node, a switchable LC resonator and switch signal input interface circuit.This switchable LC resonator is coupled between this input node and this output node, is used for to providing a plurality of switchable filter transform functions via a plurality of high-frequency signals that different frequency is arranged that transmit between this input node and this output node.This switching signal input interface circuit is coupled to this switchable LC resonator.One switches signal is applied to this switchable LC resonator via this switching signal input interface circuit, provides a suitable function in these a plurality of switchable filter transform functions to control this switchable LC resonator respectively for these a plurality of high-frequency signals with different frequency.
Preferably, this switchable LC resonator comprises an inductive unit, is coupled between this input node and ground; One first capacitive unit is coupled between this input node and ground, makes this inductive unit and this first capacitive unit constitute one first state LC resonant circuit in parallel; And one second capacitive unit, be coupled between this input node and ground, make this inductive unit, this first capacitive unit, constitute one second state LC resonant circuit in parallel with this second capacitive unit.
Preferably, this switching signal is a direct current voltage signal, has a predetermined accurate and predetermined high voltage level in low-voltage position, and to be in this predetermined low-voltage position punctual when this switching signal, this switching signal is controlled this second capacitive unit becomes the state of energizing, and when this switching signal is in this predetermined high voltage level, this switching signal is controlled this second capacitive unit becomes the state of not energizing, and makes this switchable LC resonator switch between this first state parallel connection LC resonant circuit and this second state LC resonant circuit in parallel.
Description of drawings
Fig. 1 shows the circuit diagram according to switchable high freguency bandpass filter of the present invention.
Fig. 2 (a) shows according to the high frequency equivalent circuit schematic diagram of switchable high freguency bandpass filter of the present invention when first state.
Fig. 2 (b) shows according to the high frequency equivalent circuit schematic diagram of switchable high freguency bandpass filter of the present invention when second state.
The filter transform function that is provided when first state according to switchable high freguency bandpass filter of the present invention is provided Fig. 3 (a).
The filter transform function that is provided when second state according to switchable high freguency bandpass filter of the present invention is provided Fig. 3 (b).
The element numbers explanation:
100 switchable high freguency bandpass filters
101 switchable LC resonators
102 switching signal input interface circuits
200 high frequency signal generator
201 first frequencies produce circuit
202 second frequencies produce circuit
300 buffers
400 direct currents stop circuit
C1～C5 electric capacity
The D1 diode
L1, the L2 inductance
R1 resistance
S1, the S2 high-frequency signal
f
1, f
2Frequency
Embodiment
Explanation hereinafter and accompanying drawing will make aforementioned and other purpose of the present invention, feature, more obvious with advantage.Now describe in detail according to the preferred embodiments of the invention with reference to the accompanying drawings.
Fig. 1 shows the circuit diagram according to switchable high freguency bandpass filter 100 of the present invention.With reference to Fig. 1, the input node of switchable high freguency bandpass filter 100 comes mark and its output node to come mark with reference symbol B with reference symbol A.The input node A of switchable high freguency bandpass filter 100 is in order to receive the high-frequency signal of two kinds of different frequencies that high frequency signal generator 200 exported.For example, high frequency signal generator 200 is made up of first frequency generation circuit 201 and second frequency generation circuit 202.It is to have first frequency f in order to generation that first frequency produces circuit 201
1The first high-frequency signal S1, and second frequency to produce circuit 202 be to have second frequency f in order to generation
2The second high-frequency signal S2.In an embodiment of the present invention, the second frequency f of the second high-frequency signal S2
2The first frequency f that is about the first high-frequency signal S1
1Twice.It will be apparent to those skilled in the art that according to switchable high freguency bandpass filter 100 of the present invention to be not limited thereto the embodiment that lift in the place, and can be applicable to have between the first high-frequency signal S1 and the second high-frequency signal S2 situation of any frequency relation.
For example, first frequency generation circuit 201 is formed by different voltage control oscillator (VCO) with second frequency generation circuit 202.Therefore, the suitable fm voltage V of supply
TProduce circuit 201 to first frequency and produce circuit 202, can produce the first desired high-frequency signal S1 and the second high-frequency signal S2 with second frequency.In addition, high frequency signal generator 200 is controlled by a switching signal SW, produce that circuit 201 and second frequency produce in the circuit 202 what person is in the state of energizing and what person is in (forbidding manufacture) state of not energizing with the decision first frequency, thereby that determine to be exported from high frequency signal generator 200 is the first high-frequency signal S1 or the second high-frequency signal S2.
As shown in Figure 1, in an embodiment of the present invention, the first high-frequency signal S1 and the second high-frequency signal S2 import the input node A of switchable high freguency bandpass filter 100 via a buffer 300.The output node B of switchable high freguency bandpass filter 100 then exports through first high-frequency signal and second high-frequency signal after the filter conversion process.This type of from the output node B of switchable high freguency bandpass filter 100 and the signal that comes via flow resistance retaining circuit 400 always and be coupled to a high frequency output OUT who shares.For example, direct current stops that circuit 400 is a capacitance component (not shown), and the output node B other end that the one end is coupled to switchable high freguency bandpass filter 100 then is coupled to the high frequency output OUT that this is shared.In this case, stop that by the direct current that capacitance component constituted circuit 400 can completely cut off passing through of direct current signal, do not hinder the transmission of high-frequency signal simultaneously.
With reference to Fig. 1, switchable high freguency bandpass filter 100 comprises a switchable LC resonator 101, be coupled between input node A and output node B, and a switching signal input interface circuit 102, be coupled to switchable LC resonator 101.Switchable LC resonator 101 provides switchable filter transform function via the first high-frequency signal S1 and the second high-frequency signal S2 that transmit between input node A and output node B.Via switching signal input interface circuit 102, aforementioned switching signal SW in order to control high frequency signal generator 200 also should be used for controlling switchable LC resonator 101, to determine providing suitable filter transform function respectively for the first high-frequency signal S1 with different frequency and the second high-frequency signal S2.
Particularly, switchable LC resonator 101 comprises an inductive unit that is made of first inductance L 1 and first capacitor C 1; First capacitive unit that is constituted by second capacitor C 2; And second capacitive unit that is constituted by the 3rd capacitor C 3, diode D1, the 4th capacitor C 4, with resistance R 1.In the inductive unit, an end of first inductance L 1 is coupled to an extraneous direct voltage source V
DC, the other end then is coupled to input node A and output node B.Moreover an end of first capacitor C 1 is coupled to extraneous direct voltage source V
DC, the other end is ground connection then.In first capacitive unit, an end of second capacitor C 2 is coupled to input node A and output node B, and the other end is ground connection then.In second capacitive unit, an end of the 3rd capacitor C 3 is coupled to input node A and output node B, and the other end then is coupled to the P utmost point of diode D1.The 4th capacitor C 4 is coupled in series with between the N utmost point and ground of diode D1.Resistance R 1 also is coupled in series with between the N utmost point and ground of diode D1.
Particularly, switching signal input interface circuit 102 comprises second inductance L 2 and the 5th capacitor C 5.One end of second inductance L 2 is coupled to the P utmost point of diode D1, and the other end is then in order to receive switching signal SW.One end of the 5th capacitor C 5 is coupled in second inductance L 2 in order to receive the terminal of switching signal SW, and the other end is ground connection then.In the present invention, switching signal SW is designed to have the predetermined low-voltage position standard and the d. c. voltage signal of the two states of the high voltage level of being scheduled to.In addition, the switching signal SW with predetermined low-voltage position standard can't conducting diode D1, but the conducting diode D1 then of the switching signal SW with predetermined high voltage level.For d. c. voltage signal, the effect of second inductance L 2 is as short circuit, and the effect of the 5th capacitor C 5 is as open circuit.Therefore, switching signal SW is as the P utmost point that couples directly to diode D1.
Now with reference to Fig. 1 and Fig. 2 (a) and the operation of 2 (b) detailed description according to switchable high freguency bandpass filter 100 of the present invention.At first with reference to Fig. 1, to be positioned at predetermined low-voltage position punctual as the switching signal SW via the switchable LC resonator 101 of switching signal input interface circuit 102 inputs, and diode D1 is not switched on.The result, second capacitive unit that is constituted by the 3rd capacitor C 3, diode D1, the 4th capacitor C 4, with resistance R 1 in the switchable LC resonator 101 is in (open circuit) state of not energizing, that is second capacitive unit is not contributed for the high frequency conversion function that switchable LC resonator 101 is provided.
Fig. 2 (a) shows that foundation switchable high freguency bandpass filter 100 of the present invention is positioned at the punctual high frequency equivalent circuit schematic diagram in predetermined low-voltage position at switching signal SW.With reference to Fig. 2 (a), it is punctual that high frequency signal generator 200 is designed so that proper switching signal SW is positioned at predetermined low-voltage position, and only second frequency generation circuit 202 is in the state of energizing, thereby output has second frequency f
2The second high-frequency signal S2.On the other hand, because first capacitor C 1 in the switchable LC resonator 101 can be equivalent to short circuit under the high frequency field,, first inductance L 1 is coupled in series with between input node A and ground so becoming.As a result, switchable LC resonator 101 becomes a LC antiresonant circuit of being made up of first inductance L 1 and second capacitor C 2.
Later refer again to Fig. 1, when the switching signal SW via the switchable LC resonator 101 of switching signal input interface circuit 102 inputs was positioned at predetermined high voltage level, diode D1 was switched on.The result, second capacitive unit that is constituted by the 3rd capacitor C 3, diode D1, the 4th capacitor C 4, with resistance R 1 in the switchable LC resonator 101 is in the state of energizing, that is second capacitive unit produces contribution to the high frequency conversion function that switchable LC resonator 101 is provided.
Fig. 2 (b) shows according to the high frequency equivalent circuit schematic diagram of switchable high freguency bandpass filter 100 of the present invention when switching signal SW is positioned at predetermined high voltage level.With reference to Fig. 2 (b), when high frequency signal generator 200 was designed so that proper switching signal SW is positioned at predetermined high voltage level, only first frequency generation circuit 201 was in the state of energizing, thereby output has first frequency f
1The first high-frequency signal S1.On the other hand, as previously mentioned,,, first inductance L 1 is coupled in series with between input node A and ground so becoming because first capacitor C 1 in the switchable LC resonator 101 can be equivalent to short circuit under the high frequency field.Moreover, since second capacitive unit that is constituted by the 3rd capacitor C 3, diode D1, the 4th capacitor C 4, with resistance R 1 in the switchable LC resonator 101 is in the state of energizing, so second capacitive unit must come across in the switchable LC resonator 101 shown in Fig. 2 (b).Please note in second capacitive unit shown in Fig. 2 of the present invention (b), diode D1 can be regarded as short circuit under conducting state, and the resistance value of resistance R 1 and the 4th capacitor C 4 is designed to much larger than the resistance value of the 3rd capacitor C 3, makes the 4th capacitor C 4 to be considered as short circuit under the high frequency field.As a result, switchable LC resonator 101 becomes a LC antiresonant circuit of being formed by first inductance L 1, second capacitor C 2, with the 3rd capacitor C 3.
The filter transform function that is provided according to switchable high freguency bandpass filter 100 of the present invention is provided for Fig. 3 (a) and 3 (b), wherein Fig. 3 (a) shows that to be positioned at predetermined low-voltage position punctual as switching signal SW, the filter transform function that switchable high freguency bandpass filter 100 is provided, and Fig. 3 (b) shows when switching signal SW is positioned at predetermined high voltage level, the filter transform function that switchable high freguency bandpass filter 100 is provided.
With reference to Fig. 3 (a), to be positioned at predetermined low-voltage position punctual as switching signal SW, and second frequency produces circuit 202 outputs and has second frequency f
2The second high-frequency signal S2.In the case, as previously mentioned, the LC antiresonant circuit that switchable LC resonator 101 is made up of first inductance L 1 and second capacitor C 2.From Fig. 3 (a) as can be known, switchable LC resonator 101 provides suitable filter transform function, with to having second frequency f
2The second high-frequency signal S2 carry out desired bandpass filtering function.
With reference to Fig. 3 (b), when switching signal SW was positioned at predetermined high voltage level, first frequency produced circuit 201 outputs and has first frequency f
1The first high-frequency signal S1.In the case. as previously mentioned, the LC antiresonant circuit that switchable LC resonator 101 is formed by first inductance L 1, second capacitor C 2, with the 3rd capacitor C 3.Because the existence of the 3rd capacitor C 3 makes the filter transform function of switchable LC resonator 101 be offset left, so can carry out desired bandpass filtering function to the first high-frequency signal S1 with lower frequency.In addition, clear as can be known from Fig. 3 (b), switchable LC resonator 101 can successfully prevent to have 2f under this state
1The second harmonic noise HN of frequency pass through, realize lowering the advantage that second harmonic noise HN disturbs.
In sum, can provide two kinds of different transforming function transformation functions to two kinds of different frequency signals, improve the frequency selective power, thereby reduce the interference between each frequency signal according to the switchable high freguency bandpass filter of the present invention.Moreover, can provide two kinds of different transforming function transformation functions to two kinds of different frequency signals according to switchable high freguency bandpass filter of the present invention, thereby reduce the number of necessary composition electronic building brick, the realization minification also reduces cost.
Though the present invention is illustrated as illustration by preferred embodiment, should understand: the invention is not restricted to the embodiment that this is disclosed.On the contrary, the present invention tends to contain tangible for a person skilled in the art various modifications and similar configuration.Therefore, the scope of claim should be according to the widest annotation, and this type of is revised and similar configuration to contain all.
Claims (12)
1. switchable high freguency bandpass filter; It comprises:
An one input node and an output node;
One switchable LC resonator comprises, and an inductive unit is coupled between described input node and ground; One first capacitive unit is coupled between described input node and ground, makes described inductive unit and described first capacitive unit constitute one first state LC resonant circuit in parallel; And one second capacitive unit, be coupled between described input node and ground, make described inductive unit, described first capacitive unit, constitute one second state LC resonant circuit in parallel with described second capacitive unit, wherein said switchable LC resonator is coupled between described input node and described output node, in order to providing a plurality of switchable filter transform functions with via a plurality of high-frequency signals that transmit between described input node and described output node with different frequency, and
One switches signal input interface circuit, is coupled to described switchable LC resonator,
Wherein one switches signal and is applied to described switchable LC resonator via described switching signal input interface circuit, provides a suitable function in described a plurality of switchable filter transform function to control described switchable LC resonator respectively for described a plurality of high-frequency signals with different frequency.
2. switchable high freguency bandpass filter according to claim 1, wherein said switching signal is a direct current voltage signal, has a predetermined accurate and predetermined high voltage level in low-voltage position, and to be in described predetermined low-voltage position punctual when described switching signal, described switching signal is controlled described second capacitive unit becomes the state of energizing, and when described switching signal is in described predetermined high voltage level, described switching signal is controlled described second capacitive unit becomes the state of not energizing, and makes described switchable LC resonator switch between described first state LC resonant circuit in parallel and described second state LC resonant circuit in parallel.
3. switchable high freguency bandpass filter according to claim 2 also comprises:
Flow resistance retaining circuit has a first terminal and one second terminal always, wherein said the first terminal be coupled in described output node and described second terminal as a shared high frequency output, in order to block passing through of a direct current signal.
4. switchable high freguency bandpass filter according to claim 2 also comprises:
One high frequency signal generator, be coupled in described input node, describedly have a plurality of high-frequency signals of different frequency and controlled in order to produce, only allow a described input node of input in described a plurality of high-frequency signal in making at any time by described switching signal.
5. switchable high freguency bandpass filter according to claim 4 also comprises:
One buffer is coupled between described high frequency signal generator and described input node.
6. switchable high freguency bandpass filter according to claim 4, wherein said high frequency signal generator comprises:
One first frequency produces circuit, is coupled between a fm voltage and described input node, has one first high-frequency signal of first frequency in order to generation, and
One second frequency produces circuit, is coupled between described fm voltage and described input node, has one second high-frequency signal of second frequency in order to generation,
Wherein said second frequency is greater than described first frequency, and to be in described predetermined low-voltage position punctual when described switching signal, described switching signal is controlled described second frequency generation circuit becomes the state of energizing, thereby allow described second high-frequency signal to import described input node, and when described switching signal is in described predetermined high voltage level, described switching signal is controlled described second frequency generation circuit becomes the state of energizing, thereby allows described first high-frequency signal to import described input node.
7. switchable high freguency bandpass filter according to claim 6, the described second frequency of wherein said second high-frequency signal is about the twice of the described first frequency of described first high-frequency signal.
8. switchable high freguency bandpass filter according to claim 1, wherein said inductive unit comprises:
One first inductance, one end are coupled to its other end of extraneous direct voltage source and then are coupled to described input node and described output node, and
One first electric capacity, one end are coupled to then ground connection of described its other end of extraneous direct voltage source.
9. switchable high freguency bandpass filter according to claim 1, wherein said first capacitive unit comprises:
One second electric capacity, one end are coupled to then ground connection of described input node and its other end of described output node.
10. switchable high freguency bandpass filter according to claim 1, wherein said second capacitive unit comprises:
One the 3rd electric capacity, one end are coupled to described input node and described output node;
One diode has a P utmost point and a N utmost point, and the wherein said P utmost point is coupled to the other end and the described switching signal input interface circuit of described the 3rd electric capacity, in order to receive described switching signal;
One the 4th electric capacity is coupled in series with between the described N utmost point and ground of described diode; And
One resistance is coupled in series with between the described N utmost point and ground of described diode.
11. switchable high freguency bandpass filter according to claim 10, wherein said switching signal is a direct current voltage signal, has a predetermined accurate and predetermined high voltage level in low-voltage position, and to be in described predetermined low-voltage position punctual when described switching signal, described switching signal can't the described diode of conducting, and when described switching signal was in described predetermined high voltage level, described switching signal made described diode current flow.
12. switchable high freguency bandpass filter according to claim 10, wherein said switching signal input interface circuit comprises:
The described P utmost point other end that one second inductance, one end are coupled to described diode is then in order to receiving described switching signal, and
One the 5th electric capacity, one end are coupled in described second inductance in order to receive the described other end of described switching signal, and its other end is ground connection then.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB031241050A CN100347954C (en) | 2003-04-29 | 2003-04-29 | Switchable high-frequency band filter |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB031241050A CN100347954C (en) | 2003-04-29 | 2003-04-29 | Switchable high-frequency band filter |
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| CN1543066A CN1543066A (en) | 2004-11-03 |
| CN100347954C true CN100347954C (en) | 2007-11-07 |
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| CNB031241050A Expired - Fee Related CN100347954C (en) | 2003-04-29 | 2003-04-29 | Switchable high-frequency band filter |
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Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
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| BR112014031408B1 (en) | 2012-06-18 | 2021-10-19 | Interdigital Madison Patent Holdings, Sas | APPARATUS AND METHOD FOR INSERTING ELECTRICAL ENERGY OR CONTROLLING SIGNALS IN A DIPLEXER CIRCUIT |
| US10541713B2 (en) * | 2015-06-29 | 2020-01-21 | Skyworks Solutions, Inc. | Multiplexers having hybrid circuits with resonators |
| CN105680898A (en) * | 2016-01-08 | 2016-06-15 | 上海斐讯数据通信技术有限公司 | Circuit for perfecting performance of mobile terminal |
| JP2021087035A (en) * | 2019-11-25 | 2021-06-03 | 株式会社村田製作所 | High-frequency signal transmission and reception circuit |
| CN113014222B (en) * | 2021-04-26 | 2023-08-08 | 哈尔滨海能达科技有限公司 | Band-pass filter circuit and electronic equipment |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1224276A (en) * | 1997-07-03 | 1999-07-28 | 西门子公司 | Circuit arrangement for switching and adjusting mutual parallel frequency range filter branch |
| CN1250253A (en) * | 1998-08-07 | 2000-04-12 | 艾利森电话股份有限公司 | Controllable electric wave filter |
| WO2003015301A1 (en) * | 2001-08-10 | 2003-02-20 | Hitachi Metals, Ltd. | Bypass filter, multi-band antenna switch circuit, and layered module composite part and communication device using them |
-
2003
- 2003-04-29 CN CNB031241050A patent/CN100347954C/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1224276A (en) * | 1997-07-03 | 1999-07-28 | 西门子公司 | Circuit arrangement for switching and adjusting mutual parallel frequency range filter branch |
| CN1250253A (en) * | 1998-08-07 | 2000-04-12 | 艾利森电话股份有限公司 | Controllable electric wave filter |
| WO2003015301A1 (en) * | 2001-08-10 | 2003-02-20 | Hitachi Metals, Ltd. | Bypass filter, multi-band antenna switch circuit, and layered module composite part and communication device using them |
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|---|---|
| CN1543066A (en) | 2004-11-03 |
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