CN116259941A - A reconfigurable filter - Google Patents

Abstract

The invention discloses a reconfigurable filter, comprising: a circular base plate and a numerical control plate; the circular substrate comprises a metal bottom plate and a circular dielectric plate; the middle of the circular dielectric plate is provided with a first through hole, and the edge of the circular dielectric plate is provided with a circle of second through holes; metal rings with preset heights are arranged in the first through holes, metal rings with different heights are arranged in the second through holes, and the bottom ends of the metal rings are in contact with the metal bottom plate; the numerical control plate comprises a numerical control adjustable capacitance network; the numerical control adjustable capacitance network is electrically connected with two elastic telescopic metal plugs; the distance between the two elastically telescopic metal plugs is equal to the distance between each pair of first through holes and second through holes; when two elastic telescopic metal plugs are inserted into any pair of first through holes and second through holes, parasitic inductance formed by metal rings in the pair of through holes and a numerical control adjustable capacitance network form a filter function circuit. The invention can realize flexible matching of the center frequency and the bandwidth of the filter in a wider frequency band range.

Description

A reconfigurable filter

technical field

The invention relates to the technical field of filters, in particular to a reconfigurable filter.

Background technique

In today's era of rapid development of wireless communication technology, spectrum resources are becoming increasingly scarce. In order to improve the utilization of spectrum resources, spectrum technologies such as multi-passband, spread frequency hopping and dynamic frequency allocation are widely used. Among them, reconfigurable filters are widely used in communication systems because of their adjustable passband and flexible tuning.

Reconfigurable filters include filters with reconfigurable center frequency, reconfigurable bandwidth, and reconfigurable center frequency and bandwidth at the same time. In the prior art, filters whose center frequency and bandwidth can be reconfigured at the same time are usually reconfigurable within a certain frequency range, and the frequency band is relatively limited, which cannot meet the requirement of simultaneously reconfigurable center frequency and bandwidth in a wider frequency range. .

Contents of the invention

In order to solve the above problems in the prior art, the present invention provides a reconfigurable filter.

The technical problem to be solved in the present invention is realized through the following technical solutions:

A reconfigurable filter, comprising: a circular substrate and a numerical control board;

The circular substrate includes a metal bottom plate and a circular dielectric plate;

A first through hole is provided in the middle of the circular dielectric plate, and a circle of second through holes is provided on the edge; wherein the connection line between each pair of the first through hole and the second through hole is connected to the connection line of the circular dielectric plate. One radius coincides; a metal ring with a preset height is built in the first through hole, and metal rings with different heights are built in different second through holes, and the bottom end of the metal ring is in contact with the metal bottom plate;

The numerical control board includes a numerically controlled adjustable capacitor network; the numerically controlled adjustable capacitor network is electrically connected to two elastic and retractable metal plugs; the distance between the two elastic and retractable metal plugs is equal to each pair of the first through hole and the second The distance between the two through holes;

Wherein, when the two elastically stretchable metal plugs are inserted into any pair of first through holes and second through holes, the parasitic inductance formed by the metal rings in the pair of through holes and the digitally controlled adjustable capacitor network form a filter device function circuit.

Preferably, the inner diameter of the circle of second through holes is equal, and the inner diameter is equal to the outer diameter of the metal ring.

Preferably, the diameter of the elastically stretchable metal plug is not smaller than the inner diameter of the metal ring, and is smaller than the outer diameter of the metal ring.

Preferably, the digitally controlled adjustable capacitor network includes: a first L capacitor network and a second L capacitor network;

Wherein, the first L capacitor network includes a first digitally controlled adjustable capacitor and a second digitally controlled adjustable capacitor; the first digitally controlled adjustable capacitor and the second digitally controlled adjustable capacitor are connected in series, and the series node is the first node; The end of the first numerically controlled adjustable capacitor far away from the first node is the input end of the reconfigurable filter; the end of the second numerically controlled adjustable capacitor far away from the first node is grounded;

The second L capacitor network includes a third digitally controlled adjustable capacitor and a fourth numerically controlled adjustable capacitor; the third digitally controlled adjustable capacitor and the fourth digitally controlled adjustable capacitor are connected in series, and the series node is the second node; The end of the third numerically controlled adjustable capacitor far away from the second node is the output end of the reconfigurable filter; the end of the fourth numerically controlled adjustable capacitor far away from the second node is grounded;

The first L capacitor network and the second L capacitor network are bridged together by an intermediate capacitor, and the two bridging points are respectively the first node and the second node; the two elastic stretchable metal plugs The two bridging points are electrically connected.

Preferably, the elastic and retractable metal plug includes: a socket, a spring and a metal plug;

Wherein, the socket is welded on the numerical control board; one end of the spring is connected to the socket, and the other end is connected to the metal plug.

Preferably, the circular dielectric plate is made of a non-conductive material whose electric loss tangent is less than 0.01.

Preferably, the non-conductive material includes: polyimide.

Preferably, the thickness of the non-conductive material is 1.5-5 mm.

Preferably, the diameter of the circular dielectric plate is 9-15 cm.

Advantageously, said reconfigurable filter is applied to a communication transceiver.

In the reconfigurable filter provided by the present invention, a through hole is opened on a circular dielectric plate, and a metal ring is built in the through hole, so that the parasitic inductance is formed by using the through hole and the metal ring; The heights of the metal rings are different, so it is equivalent to forming multiple inductors with different inductance values on the circular dielectric plate. When the two elastic stretchable metal plugs on the numerical control board are inserted into any pair of the first through hole and the second through hole, the parasitic inductance and the numerical control adjustable capacitance network formed by the metal rings in the two through holes can be electrically Connect together to form a filter function circuit. Among them, the inductance in the filter function circuit can be adjusted by adjusting the positions of the two elastic and retractable metal plugs on the numerical control board inserted into the through holes on the circular substrate, and the capacitance in the filter function circuit is CNC adjustable capacitor. Therefore, the reconfigurable filter provided by the present invention can flexibly adjust the capacitance and inductance in the filter functional circuit, so as to realize flexible configurability of center frequency and bandwidth and impedance matching within a wide frequency range.

The present invention will be described in further detail below in conjunction with the accompanying drawings.

Description of drawings

FIG. 1 is a schematic structural diagram of a reconfigurable filter provided by an embodiment of the present invention;

Fig. 2 is a top view of a circular substrate in the reconfigurable filter shown in Fig. 1;

Fig. 3 is a schematic structural diagram of the elastically stretchable metal plug in the reconfigurable filter shown in Fig. 1;

A filter function circuit of the reconfigurable filter shown in Figure 1 is shown in Figure 4;

Another filter functional circuit of the reconfigurable filter shown in Figure 1 is shown in Figure 5;

Figure 6 shows the transfer characteristics of the four filters reconstructed by adjusting the digitally controlled adjustable capacitor network in the embodiment of the present invention;

FIG. 7 shows the transmission characteristics of four filters reconstructed by selecting four different pairs of first through holes and second through holes in the embodiment of the present invention.

Detailed ways

The present invention will be described in further detail below in conjunction with specific examples, but the embodiments of the present invention are not limited thereto.

In order to realize the flexible configuration of the center frequency and bandwidth of the filter in a wide frequency range, the embodiment of the present invention provides a reconfigurable filter, as shown in Figure 1, the reconfigurable filter includes: Substrate and CNC board3.

Wherein, the circular substrate includes a metal base plate 1 and a circular dielectric plate 2; as shown in FIG. The connecting line between the first through hole 5 and the second through hole 6 coincides with a radius R of the circular dielectric plate 2; a metal ring with a preset height is built in the first through hole 5, which is different from that in the second through hole 6. Metal rings of different heights are built in, and the bottom end of the metal ring is in contact with the metal bottom plate 1 .

Preferably, the inner diameters of a circle of second through holes 6 on the circular dielectric plate 2 are all equal, and the inner diameters are equal to the outer diameter of the metal ring.

In practical applications, the metal rings in the first through hole and the second through hole may be formed by a metal plating process, but of course it is not limited thereto.

Preferably, the circular dielectric plate 2 is made of a non-conductive material whose electric loss tangent is less than 0.01. Here, the non-conductive material includes materials such as polyimide or benzocyclobutene.

Preferably, the thickness of the non-conductive material may be 1.5-5mm.

Preferably, the diameter of the circular dielectric plate 2 is 9-15 cm.

The numerical control board 3 includes a digitally controlled adjustable capacitor network; the digitally controlled adjustable capacitor network is electrically connected to two elastic and retractable metal plugs 4; the distance between the two elastic and retractable metal plugs 4 is equal to each pair of the first through hole 5 and the second The distance between the two through holes 6.

Wherein, the diameter of the elastically stretchable metal plug 4 is not smaller than the inner diameter of the metal ring, and smaller than the outer diameter of the metal ring. In this way, after the elastic and stretchable metal plug is inserted into the through hole on the circular dielectric board 2, it will be pushed above the metal ring by the metal ring and will not be inserted into the metal ring.

FIG. 3 exemplarily shows an elastic and retractable metal plug 4 , including: a socket 7 , a spring 8 and a metal plug 9 . Wherein, the socket 7 is welded on the numerical control board 3; one end of the spring 8 is connected to the socket 7, and the other end is connected to the metal plug 9. It can be understood that, for the elastically stretchable metal plug 4 shown in FIG. 3 , the diameter of the lower end of the metal plug 9 is not smaller than the inner diameter of the metal ring, and smaller than the outer diameter of the metal ring.

When two elastic and stretchable metal plugs 4 enter any pair of first through holes 5 and second through holes 6, the parasitic inductance formed by the metal rings in the pair of through holes and the digitally controlled adjustable capacitor network form a filter function circuit.

It can be understood that the digitally controlled adjustable capacitor network is a network composed of multiple digitally controlled adjustable capacitors; the digitally controlled adjustable capacitor is usually composed of multiple parallel fixed capacitors and MOS tubes connected in series with each fixed capacitor. By controlling the opening and closing of each MOS tube, controlling whether the fixed capacitor in series with it passes through the electrical signal, thereby controlling the number of fixed capacitors connected to the entire digitally controlled adjustable capacitor, in order to achieve the adjustment of the digitally controlled adjustable capacitor. value purpose.

FIG. 4 exemplarily shows a filter function circuit, wherein the digitally controlled adjustable capacitor network includes: a first L capacitor network and a second L capacitor network.

Wherein, the first L capacitor network includes a first digitally controlled adjustable capacitor C1 and a second digitally controlled adjustable capacitor C2; the first digitally controlled adjustable capacitor C1 and the second digitally controlled adjustable capacitor C2 are connected in series, and the series node is the first node X1; The end of a digitally controlled adjustable capacitor C1 away from the first node X1 is the input end of the reconfigurable filter; the end of the second digitally controlled adjustable capacitor C2 away from the first node X1 is grounded.

The second L capacitor network includes the third numerically controlled adjustable capacitor C3 and the fourth numerically controlled adjustable capacitor C4; the third numerically controlled adjustable capacitor C3 and the fourth numerically controlled adjustable capacitor C4 are connected in series, and the series node is the second node X2; the third The end of the digitally controlled adjustable capacitor C3 far away from the second node X2 is the output end of the reconfigurable filter; the end of the fourth digitally controlled adjustable capacitor C4 far away from the second node X2 is grounded.

The first L capacitor network and the second L capacitor network are bridged together by an intermediate capacitor C5, and the two bridge points are respectively the first node X1 and the second node X2; two elastic and retractable metal plugs 4 are electrically connected to the two bridges point.

It can be understood that the two inductances L1 and L2 in FIG. 4 are formed by the metal rings in the pair of through holes after the two elastic and stretchable metal plugs 4 are inserted into the pair of first through holes 5 and the second through holes 6 Parasitic inductance; RFin represents the RF input of the filter, and RFout represents the RF output of the filter.

Based on the filter function circuit shown in Figure 4, by setting the height of the metal ring in the first through hole 5, the inductance value of the parasitic inductance L1 can be set; by selecting the second through hole 6, the inductance value of the parasitic inductance L2 can be selected, Thereby select the working frequency band of filter; By adjusting the capacitance value of the second numerically controlled adjustable capacitor C2 and the fourth numerically controlled adjustable capacitor C4, the passband center frequency of the filter can be adjusted, and by adjusting the capacitance value of five numerically controlled adjustable capacitor C5 , the passband bandwidth of the filter can be adjusted; by adjusting the capacitance values of the first digitally controlled adjustable capacitor C1 and the third digitally controlled adjustable capacitor C3, impedance matching within the filter passband can be realized.

Fig. 5 exemplarily shows another kind of filter function circuit. Compared with the circuit shown in Fig. 4, the sixth digitally controlled adjustable capacitor C6 and the seventh digitally controlled adjustable capacitor C7 are added to the circuit, the two increased The capacitor is used as a filter capacitor to enhance and adjust the filter effect.

The beneficial effects of the embodiments of the present invention will be described below using simulation experiments.

Specifically, the heights of the metal rings in the first through hole and the second through hole are both 1.6mm, and the inductance values of the parasitic inductances L1 and L2 are both 520pH, and the inductance value is not greatly affected by the specific diameter of the metal ring. Based on the parasitic inductance L1 and L2, the working frequency band of the filter can be configured in the range of about 1.4~2.1GHz.

Then, based on the digitally controlled adjustable capacitor network shown in Figure 4, the transmission characteristics of the four filters at 0.9-2.5 GHz are reconstructed by adjusting four groups of different capacitance values, as shown in Figure 6, where the abscissa is the frequency, and the unit is GHz, the vertical axis is the transmission coefficient, the unit is dB.

Based on Figure 6, it can be seen that by adjusting the digitally controlled adjustable capacitor network for four times of reconstruction, the working frequency band of the filter changes in the range of 1.4~2.1GHz, and the center frequency and bandwidth change accordingly.

Then, based on the numerically controlled adjustable capacitor network shown in Figure 4, a set of capacitance values of the numerically controlled adjustable capacitor network was fixed, and four pairs of different first and second through holes were selected to reconstruct four different The obtained transmission characteristics of filters in the frequency band are shown in Figure 7, where four different line types correspond to the four filters.

Based on Fig. 7, it can be seen that by adjusting the quadruple reconstruction of the parasitic inductances L1 and L2, the working bandwidth of the filter is obviously shifted.

In the reconfigurable filter provided by the embodiment of the present invention, a through hole is opened on a circular dielectric plate, and a metal ring is built in the through hole, so that the parasitic inductance is formed by using the through hole and the metal ring; The heights of the built-in metal rings are different, so it is equivalent to forming multiple inductors with different inductance values on the circular dielectric board. When the two elastic stretchable metal plugs on the numerical control board are inserted into any pair of the first through hole and the second through hole, the parasitic inductance and the numerical control adjustable capacitance network formed by the metal rings in the two through holes can be electrically connected together to form a filter function circuit. Among them, the inductance in the filter function circuit can be adjusted by adjusting the positions of the two elastic and retractable metal plugs on the numerical control board inserted into the through holes on the circular substrate, and the capacitance in the filter function circuit is CNC adjustable capacitor. Therefore, the reconfigurable filter provided by the present invention can flexibly adjust the capacitance and inductance in the filter functional circuit, so as to realize flexible configurability of center frequency and bandwidth and impedance matching within a wide frequency range.

It should be noted that terms such as "first" and "second" are used to distinguish similar objects, and are not necessarily used to describe a specific sequence or sequence. It is to be understood that the data so used are interchangeable under appropriate circumstances such that the embodiments of the disclosure described herein can be practiced in sequences other than those illustrated or described herein. The implementations described in the following exemplary examples do not represent all implementations consistent with the present disclosure. Rather, they are merely examples of apparatuses and methods consistent with aspects of the present disclosure.

In the description of this specification, descriptions referring to the terms "one embodiment", "some embodiments", "example", "specific examples", or "some examples" mean that specific features described in connection with the embodiment or example Or features are included in at least one embodiment or example of the invention. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the specific features or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification.

Although the present application has been described in conjunction with various embodiments, those skilled in the art can understand and realize the disclosure of the disclosed embodiments by viewing the drawings and the disclosure in the process of implementing the claimed application. other changes. In the description of the present invention, the word "comprising" does not exclude other components or steps, "a" or "an" does not exclude a plurality of situations, and the meaning of "multiple" means two or more, unless otherwise There are clear and specific limitations. In addition, some measures are described in mutually different embodiments, but this does not mean that these measures cannot be combined to produce good effects.

In describing the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " Orientation indicated by rear, left, right, vertical, horizontal, top, bottom, inside, outside, clockwise, counterclockwise, etc. The positional relationship is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, Therefore, it should not be construed as limiting the invention.

In the present invention, unless otherwise clearly specified and limited, terms such as "installation", "connection", "connection" and "fixation" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection , or integrated; it can be mechanically connected or electrically connected; it can be directly connected or indirectly connected through an intermediary, and it can be the internal communication of two components or the interaction relationship between two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

In the present invention, unless otherwise clearly specified and limited, a first feature being "on" or "under" a second feature may include direct contact between the first and second features, and may also include the first and second features Not in direct contact but through another characteristic contact between them. Moreover, "above", "above" and "above" the first feature on the second feature include that the first feature is directly above and obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature. "Below", "beneath" and "under" the first feature to the second feature include that the first feature is directly below and obliquely below the second feature, or simply means that the first feature has a lower level than the second feature.

The above content is a further detailed description of the present invention in conjunction with specific preferred embodiments, and it cannot be assumed that the specific implementation of the present invention is limited to these descriptions. For those of ordinary skill in the technical field of the present invention, without departing from the concept of the present invention, some simple deduction or replacement can be made, which should be regarded as belonging to the protection scope of the present invention.

Claims (10)

1. A reconfigurable filter, comprising: a circular base plate and a numerical control plate;

the circular substrate comprises a metal bottom plate and a circular dielectric plate;

the middle of the circular dielectric plate is provided with a first through hole, and the edge of the circular dielectric plate is provided with a circle of second through holes; wherein the connecting line of each pair of the first through holes and the second through holes is coincident with one radius of the circular dielectric plate; metal rings with preset heights are arranged in the first through holes, metal rings with different heights are arranged in the second through holes, and the bottom ends of the metal rings are in contact with the metal bottom plate;

the numerical control plate comprises a numerical control adjustable capacitance network; the numerical control adjustable capacitance network is electrically connected with two elastic telescopic metal plugs; the distance between the two elastically telescopic metal plugs is equal to the distance between each pair of first through holes and second through holes;

when the two elastic telescopic metal plugs are inserted into any pair of the first through holes and the second through holes, parasitic inductance formed by metal rings in the pair of through holes and the numerical control adjustable capacitance network form a filter function circuit.

2. The reconfigurable filter of claim 1, wherein the inner diameters of the circle of second through holes are all equal and the inner diameters are all equal to the outer diameter of the metal ring.

3. The reconfigurable filter of claim 2, wherein the elastically stretchable metal plug has a diameter that is not smaller than an inner diameter of the metal ring and smaller than an outer diameter of the metal ring.

4. The reconfigurable filter of claim 1, wherein the digitally controlled adjustable capacitance network comprises: a first L-capacitance network and a second L-capacitance network;

the first L capacitance network comprises a first numerical control adjustable capacitor and a second numerical control adjustable capacitor; the first numerical control adjustable capacitor and the second numerical control adjustable capacitor are connected in series, and the series node is a first node; one end of the first numerical control adjustable capacitor, which is far away from the first node, is an input end of the reconfigurable filter; one end, far away from the first node, of the second numerical control adjustable capacitor is grounded;

the second L capacitance network comprises a third numerical control adjustable capacitance and a fourth numerical control adjustable capacitance; the third numerical control adjustable capacitor and the fourth numerical control adjustable capacitor are connected in series, and the series node is a second node; one end of the third numerical control adjustable capacitor, which is far away from the second node, is an output end of the reconfigurable filter; one end of the fourth numerical control adjustable capacitor far away from the second node is grounded;

the first L capacitance network and the second L capacitance network are bridged together by an intermediate capacitance, and two bridge points are the first node and the second node respectively; the two elastically stretchable metal plugs are electrically connected with the two bridging points.

5. The reconfigurable filter of claim 1, wherein the elastically stretchable metal plug comprises: socket, spring and metal plug;

wherein the socket is welded on the numerical control plate; one end of the spring is connected with the socket, and the other end of the spring is connected with the metal plug.

6. The reconfigurable filter of claim 1, wherein the circular dielectric plates are made of a non-conductive material having an electrical loss tangent less than 0.01.

7. The reconfigurable filter of claim 6, wherein the non-conductive material comprises: polyimide.

8. The reconfigurable filter of claim 6, wherein the non-conductive material has a thickness of 1.5 to 5mm.

9. The reconfigurable filter of claim 1, wherein the diameter of the circular dielectric plate is 9-15 cm9.

10. The reconfigurable filter of claim 1, applied to a communication transceiver.

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