CN114710129A - Electrically tunable filter and method for widening tuning range - Google Patents
Electrically tunable filter and method for widening tuning range Download PDFInfo
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- CN114710129A CN114710129A CN202210413271.4A CN202210413271A CN114710129A CN 114710129 A CN114710129 A CN 114710129A CN 202210413271 A CN202210413271 A CN 202210413271A CN 114710129 A CN114710129 A CN 114710129A
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
- H03H7/01—Frequency selective two-port networks
- H03H7/0153—Electrical filters; Controlling thereof
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/40—Arrangements for reducing harmonics
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Abstract
The invention discloses an electrically tunable filter and a method for widening a tuning range, which relate to the technical field of microwave communication and solve the technical problems that the volume of the existing electrically tunable filter manufactured by using a microstrip line process is greatly reduced, but the existing electrically tunable filter cannot be debugged in practical use, the production period is long, and the cost is high. The port standing wave ratio will decrease.
Description
Technical Field
The invention relates to the technical field of microwave communication, in particular to an electric tuning filter and a method for widening a tuning range.
Background
Under the increasingly crowded spectrum resources and complex electromagnetic environments, a high-performance filter is taken as an effective means for improving the situation, and is continuously paid attention and researched by researchers, and the front end of a radio frequency system formed by a multipath filter and a radio frequency switch is taken as an anti-interference technical means in the traditional broadband communication system. The method has the problems of large volume, wide bandwidth, weak anti-interference capability, general linearity, high cost and the like. The tunable filter can change the capacitance value by changing the state of the capacitor chip or changing the direct current bias of the varactor diode with a narrow bandwidth, and change the resonant frequency to continuously scan and cover a wider frequency band. The volume can be effectively reduced, the anti-interference capability is improved, however, the electrically tunable filter has a certain tuning range, and standing waves and insertion loss which exceed the tuning range are deteriorated.
The traditional electrically tunable filter is a circuit model designed based on Chebyshev or resonance coupling theory, the Chebyshev filter is not as good as an elliptical filter in out-of-band rejection, however, the elliptical filter is not widely applied to the electrically tunable filter due to the narrow tuning range. The electrically tunable filter is generally implemented by an LC or microstrip process. The common electrically tunable filter structure uses a plurality of nominal capacitors, the number of the capacitors is selected through a switch for tuning, and the electrically tunable filter manufactured in the mode has a larger volume. The electrically tunable filter manufactured by the microstrip line process has the advantages of greatly reduced volume, incapability of debugging in practical use, long production period and high cost.
Disclosure of Invention
The invention aims to: in order to solve the technical problem, the invention provides an electrically tunable filter and a method for widening a tuning range.
The invention specifically adopts the following technical scheme for realizing the purpose:
the utility model provides an electrically tunable filter, includes the harmonious frequency selection circuit of band-pass, the harmonious frequency selection circuit of band-pass is cascaded by two resonance circuit that are axisymmetric distribution and forms, and two resonance circuit pass through inductive coupling, resonance circuit connects input/output feeder respectively, and control voltage transmits varactor department to the frequency selection circuit, and control varactor is harmonious to corresponding frequency, the harmonious frequency selection circuit of band-pass includes seven high Q nominal inductance, two sets of varactor and the tuned circuit of two switches constitution.
As an optional technical solution, one end of the first inductor is grounded, the other end is connected between the input end, the second inductor and the first switch, one end of the second inductor is connected between the first inductor, the first switch and the input end, the other end is connected with the first group of varactor diodes, one end of the third inductor is connected with the switch, the other end is grounded,
one end of the fourth inductor is connected between the second inductor and the first group of variable capacitance diodes, the other end of the fourth inductor is connected between the sixth inductor and the second group of variable capacitance diodes, one end of the fifth inductor is connected with the second switch, the other end of the fifth inductor is grounded, one end of the sixth inductor is connected between the seventh inductor, the switch and the output end, the other end of the sixth inductor is connected with the second variable capacitance diodes, one end of the seventh inductor is grounded, and the other end of the seventh inductor is connected between the output end, the sixth inductor and the second switch. One end of the first group of variable capacitance diodes is grounded, the other end of the first group of variable capacitance diodes is connected between the second inductor and the fourth inductor, one end of the second group of variable capacitance diodes is grounded, the other end of the second group of variable capacitance diodes is connected between the fourth inductor and the sixth inductor, the first switch is connected between the first inductor and the third inductor, and the second switch is connected between the fifth inductor and the seventh inductor.
As an optional technical solution, the first inductance value is consistent with the seventh inductance value, the second inductance value is consistent with the sixth inductance value, and the third inductance value is consistent with the fifth inductance value.
As an alternative solution, the varactor can change the capacitance value of the output ground according to the change of the voltages applied at two ends.
As an alternative solution, the values of the first group of varactors and the second group of varactors are the same, and the output values are supplied by the same variable voltage.
A method for widening a tuning range is based on the electrically tunable filter of any one of claims 2 to 5; the center frequency of the electrically tunable filter can be changed by changing the bias voltage of the first group of variable capacitance diodes and the second group of variable capacitance diodes, the adjustable bandwidth of the inductance value of the fourth inductor is changed, the adjustable access coefficient of the inductance value of the first inductor, the second inductor, the seventh inductor and the sixth inductor is changed at the same time, the insertion loss and the standing wave are changed, the bias voltage of the first group of variable capacitance diodes and the second group of variable capacitance diodes is increased, the center frequency of the electrically tunable filter can be changed, the larger the bias voltage is, the higher the center frequency is, the larger the port standing wave ratio is, the first switch and the second switch are closed at the moment, and the port standing wave ratio is reduced.
The invention has the following beneficial effects:
1. the invention adopts LC inductor to build, and has the advantages of convenient debugging and low cost.
2. The center frequency and the bandwidth of the inductance coupling zero variable electrically tunable filter are easy to control, the center frequency can be controlled by controlling the tuning voltage and further controlling the capacitance value, and the bandwidth can be controlled by adjusting the inductance value of the coupling inductance.
3. The switch inductor provided by the invention can widen the tuning range of the electrically tunable filter.
4. The electrically tunable filter has a simple structure and is easy to process.
Drawings
FIG. 1 is a block diagram of the present invention;
FIG. 2 is a frequency response curve at a center frequency of the electrically tunable filter of 30 MHz;
FIG. 3 is a frequency response curve at a center frequency of 39MHz of the electrically tunable filter;
FIG. 4 is a frequency response curve at 39MHz of the center frequency of the electrically tunable filter after the switch inductor is connected;
fig. 5 is a frequency response curve at 52MHz of the center frequency of the electrically tunable filter after the switch inductor is connected.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.
Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be obtained by a person skilled in the art without inventive step based on the embodiments of the present invention, are within the scope of protection of the present invention.
Example 1
As shown in fig. 1, the present embodiment includes a tuning circuit composed of seven high-Q inductors, two sets of tunable varactors, and two switches. One end of the first inductor is grounded, the other end is connected among the input end, the second inductor and the first switch, one end of the second inductor is connected among the first inductor, the first switch and the input end, the other end is connected with the first group of variable capacitance diodes,
one end of the third inductor is connected with the switch, and the other end is grounded,
one end of the fourth inductor is connected between the second inductor and the first group of variable capacitance diodes, the other end of the fourth inductor is connected between the sixth inductor and the second group of variable capacitance diodes, one end of the fifth inductor is connected with the second switch, the other end of the fifth inductor is grounded, one end of the sixth inductor is connected between the seventh inductor, the switch and the output end, the other end of the sixth inductor is connected with the second variable capacitance diodes, one end of the seventh inductor is grounded, and the other end of the seventh inductor is connected between the output end, the sixth inductor and the second switch. One end of the first group of variable capacitance diodes is grounded, the other end of the first group of variable capacitance diodes is connected between the second inductor and the fourth inductor, one end of the second group of variable capacitance diodes is grounded, the other end of the second group of variable capacitance diodes is connected between the fourth inductor and the sixth inductor, the first switch is connected between the first inductor and the third inductor, and the second switch is connected between the fifth inductor and the seventh inductor.
For seven high Q inductors, the first inductor corresponds to the seventh inductance value, the second inductor corresponds to the sixth inductance value, and the third inductor corresponds to the fifth inductance value.
For the two sets of varactors in this embodiment, the first set of varactors is the same value as the second set of varactors, and the output values are supplied by the same variable voltage.
Example 2
In this embodiment, the center frequency of the electrically tunable filter can be changed by simultaneously changing the bias voltages of the first group of varactor diodes and the second group of varactor diodes, the adjustable bandwidth of the inductance value of the fourth inductor can be changed, the adjustable access coefficients of the inductance values of the first inductor, the second inductor, the seventh inductor and the sixth inductor can be changed simultaneously to change the insertion loss and the standing wave, the bias voltages of the first group of varactor diodes and the second group of varactor diodes can be increased, the center frequency of the electrically tunable filter can be changed, the higher the bias voltage is, the higher the center frequency is, the higher the port standing-wave ratio is, and at this time, the first switch and the second switch are closed, so that the port standing-wave ratio is reduced;
further, the inductance value is adjusted to make the waveform of the filter normal at the frequency of 30MHz, and by changing the tuning voltage, the amplitude-frequency response curve of the electrically tunable filter is as shown in fig. 2 and fig. 3. In the figure, DB (S21) is a signal transmission characteristic curve, and curves VSWR (1) and VSWR (2) are signal port standing wave ratio curves. As can be seen from fig. 2, when the values of the first and second varactors are 232.2pF, the center frequency of the electrically tunable filter is 30MHz, the insertion loss at the center frequency is 1.6dB, and the standing-wave ratio at the port is 1.3. As can be seen from fig. 3, when the values of the first and second varactors are 139.2pF, the center frequency of the electrically tunable filter is 39MHz, the insertion loss at the center frequency is 1.8dB, and the standing-wave ratio at the port is 2. At this time, the first switch and the second switch are closed, the third inductor and the fifth inductor are connected to the circuit, the first varactor diode and the second varactor diode are adjusted at the same time, and the amplitude-frequency response curve of the electrically tunable filter is shown in fig. 4 and fig. 5. As can be seen from fig. 4, when the values of the first and second varactors are 168.2pF, the center frequency of the electrically tunable filter is 39MHz, the in-band insertion loss is 1.6dB, and the port standing-wave ratio is 1.2. As can be seen from fig. 5, when the values of the first and second varactors are 93.2pF, the center frequency of the electrically tunable filter is 52MHz, the in-band insertion loss is 1.8dB, and the port standing-wave ratio is 2. By introducing the switch inductor, the tuning range of the electrically tunable filter is expanded.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.
Claims (6)
1. The electrically tunable filter is characterized in that the band-pass tuning frequency-selecting circuit comprises seven high-Q nominal inductors, two groups of variable capacitance diodes and a tuning circuit consisting of two switches.
2. An electrically tunable filter according to claim 1, wherein the first inductor has one end connected to ground and the other end connected between the input terminal, the second inductor and the first switch, the second inductor has one end connected between the first inductor, the first switch and the input terminal and the other end connected to the first group of varactor diodes, the third inductor has one end connected to the switch and one end connected to ground,
one end of the fourth inductor is connected between the second inductor and the first group of variable capacitance diodes, the other end of the fourth inductor is connected between the sixth inductor and the second group of variable capacitance diodes, one end of the fifth inductor is connected with the second switch, the other end of the fifth inductor is grounded, one end of the sixth inductor is connected between the seventh inductor, the switch and the output end, the other end of the sixth inductor is connected with the second variable capacitance diodes, one end of the seventh inductor is grounded, and the other end of the seventh inductor is connected between the output end, the sixth inductor and the second switch. One end of the first group of variable capacitance diodes is grounded, the other end of the first group of variable capacitance diodes is connected between the second inductor and the fourth inductor, one end of the second group of variable capacitance diodes is grounded, the other end of the second group of variable capacitance diodes is connected between the fourth inductor and the sixth inductor, the first switch is connected between the first inductor and the third inductor, and the second switch is connected between the fifth inductor and the seventh inductor.
3. The electrically tunable filter of claim 2, wherein the first inductance value corresponds to the seventh inductance value, the second inductance value corresponds to the sixth inductance value, and the third inductance value corresponds to the fifth inductance value.
4. An electrically tunable filter according to claim 2, wherein the varactor diode is adapted to change the capacitance of the output ground in response to a change in voltage applied across the varactor diode.
5. An electrically tunable filter according to claim 2, wherein the first set of varactors corresponds in value to the second set of varactors, and the output values are supplied by the same variable voltage.
6. A method for widening a tuning range is characterized in that the method is based on an electrically tunable filter of any one of claims 2 to 5; the center frequency of the electrically tunable filter can be changed by changing the bias voltage of the first group of variable capacitance diodes and the second group of variable capacitance diodes, the adjustable bandwidth of the inductance value of the fourth inductor is changed, the adjustable access coefficient of the inductance value of the first inductor, the second inductor, the seventh inductor and the sixth inductor is changed at the same time, the insertion loss and the standing wave are changed, the bias voltage of the first group of variable capacitance diodes and the second group of variable capacitance diodes is increased, the center frequency of the electrically tunable filter can be changed, the larger the bias voltage is, the higher the center frequency is, the larger the port standing wave ratio is, the first switch and the second switch are closed at the moment, and the port standing wave ratio is reduced.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210413271.4A CN114710129A (en) | 2022-04-19 | 2022-04-19 | Electrically tunable filter and method for widening tuning range |
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| CN202210413271.4A CN114710129A (en) | 2022-04-19 | 2022-04-19 | Electrically tunable filter and method for widening tuning range |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116915202A (en) * | 2023-09-14 | 2023-10-20 | 成都世源频控技术股份有限公司 | LC band-pass filter with adjustable transmission zero point |
Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6097269A (en) * | 1999-02-01 | 2000-08-01 | Motorola, Inc. | Electrically tunable band pass filter with symmetrical low-side and high-side protection |
| CN204031096U (en) * | 2014-08-21 | 2014-12-17 | 石家庄宇讯电子有限公司 | A kind of electrically tunable filter of high P-1 index |
| CN204180028U (en) * | 2014-11-06 | 2015-02-25 | 重庆会凌电子新技术有限公司 | A kind of electrically tunable filter |
| CN105322917A (en) * | 2015-11-20 | 2016-02-10 | 南京熊猫汉达科技有限公司 | A 30MHz-512MHz wide frequency band frequency hopping filter |
| CN105991105A (en) * | 2015-02-14 | 2016-10-05 | 成都宏明电子股份有限公司 | Novel LC electrically-tunable band-pass filter and LC electrically-tunable band-stop filter |
| CN110266286A (en) * | 2019-06-25 | 2019-09-20 | 电子科技大学 | A kind of LC electrically tunable filter of constant absolute bandwidth |
| CN110289831A (en) * | 2019-06-25 | 2019-09-27 | 电子科技大学 | A kind of high low pass combination LC band logical electrically tunable filter |
| CN209517086U (en) * | 2019-03-14 | 2019-10-18 | 武汉博畅通信设备有限责任公司 | A kind of broadband microminiature surface encapsulation digital tuning filter |
| CN112087212A (en) * | 2020-09-15 | 2020-12-15 | 上海鸿晔电子科技股份有限公司 | Miniaturized electric adjusting filter |
| CN112104336A (en) * | 2020-09-15 | 2020-12-18 | 上海鸿晔电子科技股份有限公司 | Wide tuning electrically tunable filter |
| CN213661585U (en) * | 2020-10-30 | 2021-07-09 | 深圳顺络迅达电子有限公司 | Micro-packaged electrically tunable filter |
| CN114257213A (en) * | 2021-12-08 | 2022-03-29 | 电子科技大学 | Adjustable band-pass tuning frequency selection circuit, electrically tunable filter and adjusting method thereof |
-
2022
- 2022-04-19 CN CN202210413271.4A patent/CN114710129A/en active Pending
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6097269A (en) * | 1999-02-01 | 2000-08-01 | Motorola, Inc. | Electrically tunable band pass filter with symmetrical low-side and high-side protection |
| CN204031096U (en) * | 2014-08-21 | 2014-12-17 | 石家庄宇讯电子有限公司 | A kind of electrically tunable filter of high P-1 index |
| CN204180028U (en) * | 2014-11-06 | 2015-02-25 | 重庆会凌电子新技术有限公司 | A kind of electrically tunable filter |
| CN105991105A (en) * | 2015-02-14 | 2016-10-05 | 成都宏明电子股份有限公司 | Novel LC electrically-tunable band-pass filter and LC electrically-tunable band-stop filter |
| CN105322917A (en) * | 2015-11-20 | 2016-02-10 | 南京熊猫汉达科技有限公司 | A 30MHz-512MHz wide frequency band frequency hopping filter |
| CN209517086U (en) * | 2019-03-14 | 2019-10-18 | 武汉博畅通信设备有限责任公司 | A kind of broadband microminiature surface encapsulation digital tuning filter |
| CN110266286A (en) * | 2019-06-25 | 2019-09-20 | 电子科技大学 | A kind of LC electrically tunable filter of constant absolute bandwidth |
| CN110289831A (en) * | 2019-06-25 | 2019-09-27 | 电子科技大学 | A kind of high low pass combination LC band logical electrically tunable filter |
| CN112087212A (en) * | 2020-09-15 | 2020-12-15 | 上海鸿晔电子科技股份有限公司 | Miniaturized electric adjusting filter |
| CN112104336A (en) * | 2020-09-15 | 2020-12-18 | 上海鸿晔电子科技股份有限公司 | Wide tuning electrically tunable filter |
| CN213661585U (en) * | 2020-10-30 | 2021-07-09 | 深圳顺络迅达电子有限公司 | Micro-packaged electrically tunable filter |
| CN114257213A (en) * | 2021-12-08 | 2022-03-29 | 电子科技大学 | Adjustable band-pass tuning frequency selection circuit, electrically tunable filter and adjusting method thereof |
Non-Patent Citations (1)
| Title |
|---|
| 刘乐乐等: "一种高抑制电调滤波器的设计与实现" * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116915202A (en) * | 2023-09-14 | 2023-10-20 | 成都世源频控技术股份有限公司 | LC band-pass filter with adjustable transmission zero point |
| CN116915202B (en) * | 2023-09-14 | 2023-12-29 | 成都世源频控技术股份有限公司 | LC band-pass filter with adjustable transmission zero point |
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