CN111355469A - Filter circuit and filter for generating extra transmission zero - Google Patents
Filter circuit and filter for generating extra transmission zero Download PDFInfo
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- CN111355469A CN111355469A CN202010183671.1A CN202010183671A CN111355469A CN 111355469 A CN111355469 A CN 111355469A CN 202010183671 A CN202010183671 A CN 202010183671A CN 111355469 A CN111355469 A CN 111355469A
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Abstract
The embodiment of the invention discloses a filter circuit and a filter for generating extra transmission zero, wherein the filter circuit comprises: a parallel resonance generating unit for generating resonance; the parallel resonance unit comprises a first branch circuit connected between the input port and the output port, a second branch circuit and a third branch circuit, wherein the first end of the second branch circuit is connected with the first end of the first branch circuit, the first end of the third branch circuit is connected with the second end of the first branch circuit, and the second end of the second branch circuit is connected with the second end of the third branch circuit and grounded; the second branch circuit and the third branch circuit are both connected in series with inductors or are both connected in series with capacitors; a parasitic element is present between the common connection point of the second end of the second branch and the second end of the third branch and ground. By using the parasitic parameters of the parasitic element, an extra transmission zero point can be generated on the premise of not increasing an extra device, the suppression degree of the filter is improved, the device cost is reduced, and the occupied space is reduced.
Description
Technical Field
The embodiment of the invention relates to the technical field of filters, in particular to a filter circuit and a filter for generating extra transmission zero.
Background
The filter can effectively filter the frequency point of the specific frequency in the power line or the frequencies except the frequency point to obtain a power signal of the specific frequency or eliminate the power signal of the specific frequency. In order to obtain a high degree of suppression, a resonant cell is often used to generate a transmission zero in filter design.
Generally, a resonance unit consists of a capacitor and an inductor, the increase of the transmission zero point of the filter is realized by increasing the number of components to form the resonance unit, and the increase of the number of the components causes the problems that the cost of the filter is high, the occupied space is large and the like.
Disclosure of Invention
The embodiment of the invention provides a filter circuit and a filter for generating an extra transmission zero point, so as to increase the extra transmission zero point, improve the suppression degree of the filter and reduce the cost and the occupied space of devices.
In a first aspect, an embodiment of the present invention provides a filter circuit for generating an extra transmission zero, including:
a parallel resonance generating unit for generating resonance;
the parallel resonance unit comprises a first branch connected between an input port and an output port, and further comprises a second branch and a third branch, wherein the first end of the second branch is connected with the first end of the first branch, the first end of the third branch is connected with the second end of the first branch, and the second end of the second branch is connected with the second end of the third branch and grounded;
the second branch and the third branch are both connected in series with inductors, or the second branch and the third branch are both connected in series with capacitors;
a parasitic element is present between a common connection point of the second end of the second branch and the second end of the third branch and ground.
Optionally, the frequency of the transmission zero generated by the parallel resonance generating unit is adjusted according to the value of the parasitic parameter of the parasitic element.
Optionally, when the second branch and the third branch are both connected in series with an inductor, the parallel resonance generating unit further includes a first capacitor, and the first capacitor is connected in series to the first branch.
Optionally, when capacitors are connected in series to the second branch and the third branch, the parallel resonance generating unit further includes a first inductor, and the first inductor is connected in series to the first branch.
Optionally, the first branch includes: a resonance unit; the resonance unit is connected between the first end of the first branch and the first end of the second branch.
Optionally, when capacitors are connected in series to the second branch and the third branch, the parallel resonance generating unit further includes a second capacitor, and the second capacitor is connected between a common connection point of the second end of the second branch and the second end of the third branch and ground.
Optionally, the parasitic element is connected between a common connection point of the second end of the second branch and the second end of the third branch and ground.
Optionally, the parasitic element generates a parasitic inductance.
In a second aspect, an embodiment of the present invention provides a filter including the filter circuit for generating an extra transmission zero as described in the first aspect.
Optionally, the filter includes:
a high pass filter and a low pass filter;
the high-pass filter comprises a second branch and a third branch which are both connected in series with inductors, and a first branch is connected in series with a capacitor or a resonance unit; the second branch circuit and the third branch circuit of the low-pass filter are both connected with a capacitor in series; the first branch is connected with an inductance or resonance unit in series.
The embodiment of the invention provides a filter circuit and a filter for generating an extra transmission zero point, wherein the filter circuit for generating the extra transmission zero point comprises: a parallel resonance generating unit for generating resonance; the parallel resonance unit comprises a first branch connected between an input port and an output port, and further comprises a second branch and a third branch, wherein the first end of the second branch is connected with the first end of the first branch, the first end of the third branch is connected with the second end of the first branch, and the second end of the second branch is connected with the second end of the third branch and grounded; the second branch and the third branch are both connected in series with an inductor, or the second branch and the third branch are both connected in series with a capacitor; a parasitic element is present between a common connection point of the second end of the second branch and the second end of the third branch and ground. The technical scheme provided by the invention forms the extra absorption zero point by using the parasitic parameters generated by the parasitic element of the circuit, meets the requirement of adding the extra transmission zero point on the premise of not adding extra devices, improves the suppression degree of the filter, and reduces the cost and the occupied space of the devices.
Drawings
Fig. 1 is a schematic structural diagram of a filter circuit for generating an extra transmission zero according to an embodiment of the present invention;
fig. 2 is a circuit diagram of a filter circuit in a high-pass filter provided in the prior art;
FIG. 3 is a frequency characteristic simulation diagram of the filter circuit of FIG. 2;
fig. 4 is a circuit diagram of a filter circuit in a low-pass filter provided in the prior art;
FIG. 5 is a frequency characteristic simulation diagram of the filter circuit of FIG. 4;
fig. 6 is a circuit diagram of a filter circuit for generating an extra transmission zero according to a second embodiment of the present invention;
fig. 7 is a simulation diagram of frequency characteristics at the time of a short circuit between the common connection point C of the filter circuit shown in fig. 6 and the ground GND;
fig. 8 is a simulation diagram of frequency characteristics at the time of an open circuit between the common connection point C of the filter circuit shown in fig. 6 and the ground GND;
fig. 9 is a simulation diagram of the frequency characteristics of the filter circuit shown in fig. 6;
fig. 10 is a circuit diagram of a filter circuit for generating an extra transmission zero according to a third embodiment of the present invention;
fig. 11 is a simulation diagram of frequency characteristics at the time of a short circuit between the common connection point C of the filter circuit shown in fig. 10 and the ground GND;
fig. 12 is a simulation diagram of frequency characteristics at the time of an open circuit between the common connection point C of the filter circuit shown in fig. 10 and the ground GND;
fig. 13 is a simulation diagram of the frequency characteristics of the filter circuit shown in fig. 10.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.
Example one
Fig. 1 is a schematic structural diagram of a filter circuit for generating an extra transmission zero according to an embodiment of the present invention, and referring to fig. 1, the filter circuit includes:
a parallel resonance generating unit for generating resonance;
the parallel resonance unit comprises a first branch circuit 10 connected between an input port A and an output port B, and further comprises a second branch circuit 20 and a third branch circuit 30, wherein the first end of the second branch circuit 20 is connected with the first end of the first branch circuit 10, the first end of the third branch circuit 30 is connected with the second end of the first branch circuit 10, and the second end of the second branch circuit 20 is connected with the second end of the third branch circuit 30 and grounded GND;
wherein, the second branch 20 and the third branch 30 are both connected in series with an inductor, or the second branch 20 and the third branch 30 are both connected in series with a capacitor;
a parasitic element 40 is present between the common connection point C of the second end of the second branch 20 and the second end of the third branch 30 and ground GND.
Specifically, in order to obtain a higher suppression degree during filter design, a transmission zero needs to be added; the transmission zero point is derived from the fact that signals are superposed together after passing through the two branches, and the phases meet a certain relation and then are mutually offset, so that a zero point is generated, and the output signals at the frequency are strongly restrained. The filter circuit for generating the extra transmission zero comprises a parallel resonance generating unit, a filter unit and a control unit, wherein the parallel resonance generating unit is used for generating resonance, and the transmission zero exists on the resonance frequency; the frequency of the transmission zero point can be adjusted by adjusting the parasitic parameters; the parallel resonance unit comprises a first branch circuit 10 connected between an input port A and an output port B, and further comprises a second branch circuit 20 and a third branch circuit 30, wherein the first end of the second branch circuit 20 is connected with the first branch circuit 10, the first end of the third branch circuit 30 is connected with the first branch circuit 10, and the second end of the second branch circuit 20 is connected with the second end of the third branch circuit 30 and grounded; wherein, the first end of the second branch 20 is connected to the first end of the third branch 30 at a different position; the second branch 20 and the third branch 30 are both connected in series with an inductor, or the second branch 20 and the third branch 30 are both connected in series with a capacitor; between the common connection point C of the second end of the second branch 20 and the second end of the third branch 30 and the ground GND, there is a specific parasitic element 40, and the frequency of the transmission zero point can be adjusted by adjusting the parameter of the parasitic element.
The filter comprises a high-pass filter (high-pass filter) and a Low-pass filter (Low-pass filter); the low-pass filter allows the passing of low-frequency signals; the high-pass filter, in contrast, allows high frequencies to pass easily while blocking low frequencies, removing unnecessary low frequency components from the signal. Fig. 2 is a circuit diagram of a filter circuit in a high-pass filter provided in the prior art, referring to fig. 2; in the prior art, a second branch of a filter circuit in a high-pass filter is connected with a second inductor L2 in series, a third inductor L3 is connected with a third branch in series, the second inductor L2 and the third inductor L3 are respectively connected with a ground GND in series, a first capacitor C1 is connected with the first branch in series, and a second end of the first capacitor C1 is electrically connected with a first end of a fifth capacitor C5; fig. 3 is a simulation diagram of frequency characteristics of the filter circuit of fig. 2, referring to fig. 3, when the filter circuit in the high pass filter is not additionally generated with transmission zeros.
Fig. 4 is a circuit diagram of a filter circuit in a low pass filter provided in the prior art, referring to fig. 4; in the prior art, a second branch of a filter circuit in a low-pass filter is connected in series with a third capacitor C3, the third branch is connected in series with a fourth capacitor C4, the third capacitor C3 and the fourth capacitor C4 are respectively connected to GND, a first inductor L1 is connected in series with the first branch, and a first end of a first inductor L1 is electrically connected with a second end of a fourth inductor L4; fig. 5 is a simulation diagram of frequency characteristics of the filter circuit of fig. 4, referring to fig. 5, when the filter circuit in the low pass filter is not additionally generated with transmission zeros.
In order to obtain a high suppression degree, a filter in the prior art needs to use a resonance unit to generate a transmission zero point, generally, one resonance unit consists of a capacitor and an inductor, and the number of components is increased when the transmission zero point is increased. The technical scheme provided by the embodiment of the invention utilizes the parasitic parameters of the circuit to form an additional absorption zero point. The filter can additionally generate available transmission zero points on the premise of not increasing additional devices, meets the requirement of increasing additional transmission zero points, improves the suppression degree of the filter, and reduces the cost and the occupied space of the devices.
The filter circuit for generating the extra transmission zero provided by the embodiment of the invention comprises: a parallel resonance generating unit for generating resonance; the parallel resonance unit comprises a first branch connected between the input port and the output port, a second branch and a third branch, wherein the first end of the second branch is connected with the first end of the first branch, the first end of the third branch is connected with the second end of the first branch, and the second end of the second branch is connected with the second end of the third branch and grounded; the second branch and the third branch are both connected in series with inductors, or the second branch and the third branch are both connected in series with capacitors; a parasitic element is present between the common connection point of the second end of the second branch and the second end of the third branch and ground. The parasitic parameters generated by the parasitic elements of the circuit are used for forming extra absorption zero points, so that the available transmission zero points can be additionally generated on the premise of not increasing extra devices, the suppression degree of the filter is improved, and the cost and the occupied space of the devices are reduced.
Example two
On the basis of the foregoing embodiment, a second embodiment of the present invention provides a filter circuit for generating an extra transmission zero, where the parallel resonance generating unit further includes a first capacitor, and the first capacitor is connected in series to the first branch; the parasitic element is connected between a common connection point of the second end of the second branch and the second end of the third branch and the ground; the filter circuit for generating an additional transmission zero is suitable for use in a high-pass filter.
Fig. 6 is a circuit diagram of a filter circuit for generating an extra transmission zero according to an embodiment of the present invention, and referring to fig. 6, the filter circuit for generating an extra transmission zero includes:
a parallel resonance generating unit for generating resonance;
the parallel resonance unit comprises a first branch circuit connected between the input port A and the output port B, and a first capacitor C1 is connected in series on the first branch circuit. The parallel resonance unit further comprises a second branch and a third branch, wherein the first end of the second branch is connected with the first branch, and the first end of the third branch is connected with the first branch. The second branch is connected with a second inductor L2 in series, and the third branch is connected with a third inductor L3 in series.
A preset parasitic parameter is generated between a common connection point C of the second end of the second branch and the second end of the third branch and the ground GND; the parasitic parameter is generated by a parasitic element 40, the parasitic element 40 being connected between the common connection point C of the second and third branches and ground GND.
Optionally, the parasitic element 40 generates a parasitic inductance Lc 12.
Specifically, the second branch of the filter circuit for generating the extra transmission zero provided by the embodiment of the present invention is connected in series with a second inductor L2, and the third branches are connected in series with a third inductor L3, that is, the filter circuit is configured as a high-pass filter. The second terminal of the second inductor L2 is electrically connected to the second terminal of the third inductor L3, and the parasitic element 40 is connected between the common node C of the second terminal of the second inductor L1 and the second terminal of the third inductor L3 and the ground GND. Fig. 7 is a simulation diagram of frequency characteristics at the time of a short circuit between the common connection point C of the filter circuit shown in fig. 6 and the ground GND; when the common connection point C is short-circuited with the ground GND, that is, the parasitic element 40 is short-circuited, the value of the parasitic inductance generated by the parasitic element 40 can be seen as zero, and the common connection point C is directly grounded with the ground GND, so that the formed circuit is equivalent to a filter circuit in a conventional high-pass filter. Referring to fig. 7, the curve relationship between the frequency and the transmission curve dB (S21) is consistent with the curve relationship between the frequency and the transmission curve dB (S21) generated by the filter circuit in the conventional high pass filter, and the extra transmission zero frequency is zero, i.e., no extra transmission zero is generated. Fig. 8 is a simulation diagram of frequency characteristics at the time of an open circuit between the common connection point C of the filter circuit shown in fig. 6 and the ground GND; when there is an open circuit between the common connection point C and the ground GND, i.e., the parasitic element 40 is open, the value of the parasitic inductance can be regarded as infinite. The circuit formed at this time is that the second inductor L2 is connected in series with the third inductor L3 and then connected in parallel with the first capacitor C1, and the simulation result thereof, referring to fig. 8, can generate an extra transmission zero point.
As can be seen from fig. 7, the additional transmission zero frequency is zero when the parasitic inductance value is zero in the filter circuit shown in fig. 6; as can be seen from fig. 8, the additional transmission zero frequency of the filter circuit shown in fig. 6 is 3.75GHz when the parasitic inductance value is infinite. It is shown that the frequency of the additional transmission zero decreases from 3.75GHz in fig. 8 to 0 in fig. 7 during the process of decreasing the value of the parasitic inductance Lc23 from infinity to zero, i.e. adjusting the value of the parasitic element 40 can control the frequency of the additional transmission zero. Exemplarily, fig. 9 is a frequency characteristic simulation diagram of the filter circuit shown in fig. 6, referring to fig. 9; when the value of the parasitic inductance Lc23 is between infinity and zero, the frequency at which the additional transmission zero is generated is between 0 in fig. 7 and 3.75GHz in fig. 8. For high pass filters, the transmission zero is typically located at lower frequencies, so the Lc23 value is typically small and is replaced by the parasitic parameters of the circuit.
Optionally, the first branch can be replaced by a resonance unit; the resonance unit is connected between the first end of the first branch and the first end of the second branch. The resonant unit is a basic structure in the filter, the capacitor and the inductor can form the resonant unit in a parallel or series connection mode, and in addition, the resonant unit can be manufactured in many other modes, such as a section of transmission line or a cavity.
Optionally, the parasitic element includes: a via or lead connected between a common connection point of the second end of the second leg and the second end of the third leg and ground. The lead is a lead led out from the inside of the component packaging body. The wire has a certain inductance value, and the inductance value of the wire can be adjusted by extending the wire between the common connection point C and the ground GND. In the circuit board, one line jumps from one side of the board to the other side, and a hole connecting two connecting lines is a via hole. The parasitic element generally includes a via or a lead, and the parasitic parameters of the via and the lead are inductance. I.e., the parasitic inductance can be formed by vias or wires without the need to add additional components.
The filter circuit for generating the extra transmission zero point provided by the embodiment of the invention is suitable for a high-pass filter, and preset parasitic parameters are generated between the common connection point of the second end of the second branch and the second end of the third branch and the ground. The parasitic parameters are generated by the parasitic elements, the parasitic elements comprise parasitic inductors, and the parasitic parameters of the circuit are used for forming extra transmission zero points, so that the available transmission zero points can be additionally generated on the premise of not increasing extra devices, the suppression degree of the high-pass filter is improved, and the cost and the occupied space of the devices are reduced.
EXAMPLE III
On the basis of the above embodiment, a third embodiment of the present invention provides a filter circuit for generating an extra transmission zero, wherein the parallel resonance generating unit further includes a first inductor, and the first inductor is connected in series to the first branch; the parallel resonance generation unit further comprises a second capacitor, and the second capacitor is connected between a common connection point of the second end of the second branch and the second end of the third branch and the ground; the parasitic element is connected between a common connection point of the second end of the second branch and the second end of the third branch and the ground; the filter circuit for generating an extra transmission zero is suitable for use in a low-pass filter.
Fig. 10 is a circuit diagram of a filter circuit for generating an extra transmission zero according to a third embodiment of the present invention, and referring to fig. 10, the filter circuit for generating an extra transmission zero includes:
a parallel resonance generating unit for generating resonance;
the parallel resonance unit comprises a first branch connected between the input port A and the output port B, and a first inductor L1 is connected in series on the first branch. The parallel resonance unit further comprises a second branch and a third branch, the first end of the second branch is connected with the first branch, the first end of the third branch is connected with the first branch, and the connecting position of the first end of the second branch is different from that of the first end of the third branch. The second branch is connected in series with a third capacitor C3, and the third branch is connected in series with a fourth capacitor C4.
A preset parasitic parameter is generated between a common connection point C of the second end of the second branch and the second end of the third branch and the ground GND; the parasitic parameter is generated by a parasitic element 40, the parasitic element 40 being connected between the common connection point C of the second and third branches and ground GND. The parallel resonance generating unit further includes a second capacitance Cc34, the second capacitance Cc34 being connected in series with the parasitic element 40 between the common connection point C and the ground GND.
Optionally, the parasitic element generates a parasitic inductance Lc 34.
Specifically, the second branch of the filter circuit for generating the extra transmission zero provided by the embodiment of the present invention is connected in series with a third capacitor C3, and the third branch is connected in series with a fourth capacitor C4, which is a low-pass filter. The parasitic element 40 and the second capacitance Cc34 between the common connection point C of the second and third branch's second ends and ground GND are connected in series. Fig. 11 is a simulation diagram of frequency characteristics at the time of a short circuit between the common connection point C of the filter circuit shown in fig. 10 and the ground GND; when the common connection point C is short-circuited with the ground GND, that is, the parasitic element 40 and the second capacitor Cc34 are short-circuited at the same time, the value of the parasitic inductance included in the parasitic element 40 and the second capacitance value can be considered to be zero, the common connection point C between the second end of the second branch and the second end of the third branch is directly grounded with the ground GND, the formed circuit is equivalent to a filter circuit in a conventional low-pass filter, a simulation result of the circuit is shown in fig. 11, and the frequency of the extra transmission zero point is zero, that is, no extra transmission zero point is generated at this time. Fig. 12 is a simulation diagram of frequency characteristics at the time of an open circuit between the common connection point C of the filter circuit shown in fig. 10 and the ground GND; when the common connection point C is open-circuited with the ground GND, it can be regarded that the values of the parasitic inductance Lc34 and/or the second capacitance Cc34 are infinite, and at this time, the formed circuit is that the third capacitance C3 is connected in series with the fourth capacitance C4 and then connected in parallel with the first inductance L1, and the simulation result refers to fig. 12, and an additional transmission zero point can be generated. Fig. 13 is a simulation diagram of the frequency characteristics of the filter circuit shown in fig. 10, with reference to fig. 13; when the second capacitor Cc34 and the parasitic inductor Lc34 are both normally connected, that is, when the values of the parasitic inductor Lc34 and the second capacitor Cc34 are between zero and infinity, the second capacitor Cc34 and the parasitic inductor Lc34 connected in series to the ground GND form another additional transmission zero point, and finally two additional transmission zero points can be formed. The Lc34 value is typically small and can be replaced by parasitic parameters of the components. Only one additional capacitor is needed to generate two transmission zeros.
Optionally, the first branch can be replaced by a resonance unit; the resonance unit is connected between the first end of the first branch and the first end of the second branch.
Optionally, the parasitic element includes: a via or lead; the via or the lead is connected between a common connection point of the second end of the second branch and the second end of the third branch and the ground.
The filter circuit for generating the extra transmission zero provided by the embodiment of the invention is suitable for a low-pass filter, and a preset parasitic parameter is generated between a common connecting point of the second end of the second branch and the second end of the third branch and the ground. The parasitic parameters are generated by the parasitic elements, the parasitic elements comprise parasitic inductors, the parasitic parameters of the circuit are used for forming extra transmission zero points, and meanwhile, two extra transmission zero points can be generated only by additionally adding a second capacitor, so that the suppression degree of the low-pass filter is further improved, and the cost and the occupied space of the device are reduced.
The embodiment of the invention also provides a filter, which comprises the filter circuit for generating the extra transmission zero point according to any one of the above embodiments. The same technical effects as the above embodiments are achieved, and are not described in detail herein.
Wherein, the filter includes:
a high pass filter and a low pass filter;
the high-pass filter comprises a second branch and a third branch which are both connected in series with inductors, and a first branch is connected in series with a capacitor or a resonance unit; the second branch circuit and the third branch circuit of the low-pass filter are both connected with a capacitor in series; the first branch is connected with an inductance or resonance unit in series.
It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.
Claims (10)
1. A filter circuit for generating an extra transmission zero, comprising:
a parallel resonance generating unit for generating resonance;
the parallel resonance unit comprises a first branch connected between an input port and an output port, and further comprises a second branch and a third branch, wherein the first end of the second branch is connected with the first end of the first branch, the first end of the third branch is connected with the second end of the first branch, and the second end of the second branch is connected with the second end of the third branch and grounded;
the second branch and the third branch are both connected in series with inductors, or the second branch and the third branch are both connected in series with capacitors;
a parasitic element is present between a common connection point of the second end of the second branch and the second end of the third branch and ground.
2. The filter circuit for generating an additional transmission zero according to claim 1, wherein a frequency of the transmission zero generated by the parallel resonance generating unit is adjusted according to a value of a parasitic parameter of the parasitic element.
3. The filter circuit for generating extra transmission zeros of claim 1, wherein when inductors are connected in series to the second branch and the third branch, the parallel resonance generating unit further comprises a first capacitor, and the first capacitor is connected in series to the first branch.
4. The filter circuit for generating extra transmission zeros of claim 1, wherein when a capacitor is connected in series to each of the second branch and the third branch, the parallel resonance generating unit further comprises a first inductor, and the first inductor is connected in series to the first branch.
5. The filter circuit for generating extra transmission zeros of claim 1, wherein the first branch comprises: a resonance unit; the resonance unit is connected between the first end of the first branch and the first end of the second branch.
6. The filter circuit for generating extra transmission zeros of claim 4, wherein when capacitors are connected in series to the second branch and the third branch, the parallel resonance generating unit further comprises a second capacitor, and the second capacitor is connected between a common connection point of the second end of the second branch and the second end of the third branch and ground.
7. The filter circuit for generating additional transmission zeros of claim 1 wherein the parasitic element comprises a via or a lead connected between a common connection of the second end of the second leg and the second end of the third leg and ground.
8. The filter circuit for generating additional transmission zeros of claim 7 wherein said parasitic element generates parasitic inductance.
9. A filter comprising a filter circuit according to any of claims 1-8 for generating an additional transmission zero.
10. The filter of claim 9, comprising:
a high pass filter and a low pass filter;
the high-pass filter comprises a second branch and a third branch which are both connected in series with inductors, and a first branch is connected in series with a capacitor or a resonance unit; the second branch circuit and the third branch circuit of the low-pass filter are both connected with a capacitor in series; the first branch is connected with an inductance or resonance unit in series.
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| CN202010183671.1A CN111355469A (en) | 2020-03-16 | 2020-03-16 | Filter circuit and filter for generating extra transmission zero |
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| CN202010183671.1A CN111355469A (en) | 2020-03-16 | 2020-03-16 | Filter circuit and filter for generating extra transmission zero |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113037239A (en) * | 2021-02-23 | 2021-06-25 | 安徽安努奇科技有限公司 | Filter and electronic device |
| CN115955200A (en) * | 2022-12-31 | 2023-04-11 | 广州慧智微电子股份有限公司 | Amplifier circuit, amplifier and electronic equipment |
-
2020
- 2020-03-16 CN CN202010183671.1A patent/CN111355469A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113037239A (en) * | 2021-02-23 | 2021-06-25 | 安徽安努奇科技有限公司 | Filter and electronic device |
| CN115955200A (en) * | 2022-12-31 | 2023-04-11 | 广州慧智微电子股份有限公司 | Amplifier circuit, amplifier and electronic equipment |
| CN115955200B (en) * | 2022-12-31 | 2024-04-05 | 广州慧智微电子股份有限公司 | Amplifier circuit, amplifier and electronic equipment |
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