Filter and multiplexer

Abstract

A filter and a multiplexer. The filter comprises a sealing structure (400), a decoupling network (200) and at least two resonators (300), wherein the sealing structure (400) is arranged around the at least two resonators (300) and is grounded; the decoupling network (200) is connected between the resonators (300) and the ground, and the at least two resonators (300) are connected between a first port and a second port of the filter; there is a coupling network (100) between the resonators (300) and the ground; and at the same frequency, an equivalent impedance value of the decoupling network (200) and an equivalent impedance value of the coupling network (100) have opposite signs.

Description

Filter and multiplexer

[0001] This application claims priority to the Chinese patent application No. 202410870907.7, filed on July 01, 2024, with the Chinese Patent Office, the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the technical field of signal processing, for example, to a filter and a multiplexer. BACKGROUND

[0003] The existing filter usually adopts a metal sealing ring for sealing to ensure the air tightness of the filter. However, the metal sealing ring will generate a coupling path between the input and output of the filter, thereby reducing the filtering performance of the filter. SUMMARY

[0004] The present application provides a filter and a multiplexer to solve the problem that the coupling path generated by the sealing ring of the existing filter and the resonator in the filter will reduce the filtering performance of the filter.

[0005] The present application provides a filter, comprising a sealing structure, a decoupling network and at least two resonators, the sealing structure is arranged around the at least two resonators and is grounded; the decoupling network is connected between the resonator and the ground, and at least two resonators are connected between the first port and the second port of the filter; the resonator has a coupling network with the ground; at the same frequency, the equivalent impedance value of the decoupling network and the equivalent impedance value of the coupling network are of opposite signs.

[0006] Optionally, the at least two resonators comprise at least two series resonators, and the at least two series resonators are connected in series between the first port and the second port; the decoupling network comprises at least two first decoupling networks, and each first decoupling network is connected between a series resonator and the ground.

[0007] Optionally, the at least two resonators comprise a parallel resonator, the parallel resonator is connected with a series node, the decoupling network comprises a second decoupling network, and the second decoupling network is connected between the parallel resonator and the ground; wherein the series node comprises a node between the first port, the second port and the series resonators connected in series between the first port and the second port.

[0008] Optionally, the decoupling network comprises a first conductive structure, one end of the first conductive structure is connected with the resonator, and the other end is connected with the ground.

[0009] Optionally, the first conductive structure comprises an inductive element or a connecting wire.

[0010] Optionally, the decoupling network further comprises a capacitive element, a first end of the capacitive element is connected with the first conductive structure, and a second end of the capacitive element is connected with the resonator or the ground.

[0011] Optionally, the capacitive element comprises a second conductive structure and a third conductive structure, a first end of the second conductive structure is connected with the first conductive structure, an end surface of a second end of the second conductive structure is arranged opposite to an end surface of a first end of the third conductive structure, and a second end of the third conductive structure is connected with the resonator or the ground.

[0012] Optionally, the end surface of the second end of the second conductive structure and the end surface of the first end of the third conductive structure are concave-convex structures.

[0013] The end surface of the second end of the second conductive structure and the end surface of the first end of the third conductive structure are arranged in a concave-convex staggered manner, and a gap is arranged between the end surface of the second end of the second conductive structure and the end surface of the first end of the third conductive structure.

[0014] Optionally, a dielectric layer is arranged between the gaps, and the dielectric layer is used to adjust a capacitance value of the capacitive element.

[0015] Embodiments of the present application provide a multiplexer, comprising the filter of any one of the above, a first end, and at least two second ends, the filter being connected in series between the first end and any one of the second ends. BRIEF DESCRIPTION OF DRAWINGS

[0016] FIG. 1 is a schematic diagram of an equivalent circuit structure of a filter according to an embodiment of the present application;

[0017] FIG. 2 is a schematic diagram of an equivalent circuit structure of a filter according to the related art;

[0018] FIG. 3 is a schematic diagram of a transmission characteristic curve of a filter according to an embodiment of the present application;

[0019] FIG. 4 is a schematic diagram of an equivalent circuit structure of another filter according to an embodiment of the present application;

[0020] FIG. 5 is a schematic diagram of an equivalent circuit structure of another filter according to an embodiment of the present application;

[0021] FIG. 6 is a schematic diagram of an equivalent circuit structure of another filter according to an embodiment of the present application;

[0022] FIG. 7 is a schematic diagram of a transmission characteristic curve of another filter according to an embodiment of the present application;

[0023] Fig. 8 is an enlarged view of the filter transmission characteristic curve shown in Fig. 7 in the adjacent band;

[0024] Fig. 9 is a schematic diagram of an equivalent circuit structure of another filter provided by the embodiments of the present application;

[0025] Fig. 10 is a schematic diagram of a filter provided by the embodiments of the present application;

[0026] Fig. 11 is a schematic diagram of a multiplexer provided by the embodiments of the present application. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of the present application.

[0028] The terms "first", "second", and the like in the specification and claims of the present application and the above-described drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or a chronological sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to the process, method, product or device.

[0029] Fig. 1 is a schematic diagram of an equivalent circuit structure of a filter provided by the embodiments of the present application. Referring to Fig. 1, the filter provided by the embodiments of the present application includes a sealing structure 400, a decoupling network 200, and at least two resonators 300. The sealing structure 400 is arranged around the at least two resonators 300 and is grounded GND. The decoupling network 200 is connected between the resonators 300 and the ground GND. The at least two resonators 300 are connected between a first port A and a second port B of the filter. The resonators 300 have a coupling network 100 between the resonators 300 and the ground GND. At the same frequency, the equivalent impedance value of the decoupling network 200 and the equivalent impedance value of the coupling network 100 are of opposite signs.

[0030] The sealing structure 400 can be a metal sealing ring of the filter. The sealing structure 400 is used to encapsulate the resonators 300 and the substrate chip in the filter, and ensure the air tightness of the filter. The sealing structure 400 can provide a new coupling path, thus causing the resonators 300 to have a coupling network with each other or with the ground GND, and affecting the filtering performance of the filter. The sealing structure 400 can be connected to the ground GND, thus reducing the influence of the coupling path formed by the sealing structure 400 on the filtering performance of the filter. The resonators 300 can be connected in series or in parallel, or in series-parallel. The present embodiment does not limit the connection structure of the resonators 300. For example, FIG. 1 shows that the filter includes two resonators 300 connected in series and three resonators 300 connected in parallel. The first port A can be the input port of the filter, and the second port B can be the output port of the filter. The resonators 300 and the sealing structure 400 form a coupling network 100. That is, the resonators 300 and the sealing structure 400 form a coupling path between the input and output ports of the filter, and the formed coupling path can affect the adjacent channel rejection of the filter, thus affecting the filtering performance of the filter. The equivalent impedance of the coupling network 100 at different frequencies is different, that is, the equivalent impedance of the coupling network 100 at different frequencies can be capacitive or inductive. The present embodiment does not limit the equivalent impedance characteristics of the coupling network. For example, FIG. 1 shows that the coupling network 100 of the two resonators 300 connected in series is capacitive, and the equivalent impedances thereof are coupling capacitances C11 and C12, respectively. One end of the decoupling network 200 is connected to the resonator 300, and the other end is connected to the ground GND through the sealing structure 400, which is equivalent to connecting the decoupling network 200 in parallel to the coupling network 100 at both ends. At the same frequency, the equivalent impedance of the decoupling network 200 and the equivalent impedance of the coupling network 100 are of opposite signs, so that the decoupling network 200 and the coupling network 100 connected in parallel can resonate, and at least partially offset the influence of the coupling network 100 on the filtering performance of the filter. That is, by connecting the decoupling network 200 in parallel to the coupling network 100 and making the equivalent impedance of the decoupling network 200 and the equivalent impedance of the coupling network 100 be of opposite signs, the coupling path formed between the resonators 300 and the sealing structure 400 can be eliminated, and the filtering performance of the filter can be improved.

[0031] FIG. 2 is an equivalent circuit structure diagram of a filter provided by the related art; FIG. 3 is a transmission characteristic curve diagram of a filter provided by an embodiment of the present application. In FIG. 3, curve L1 is a transmission characteristic curve of the filter when the decoupling network 200 is provided in FIG. 1, and curve L2 is a transmission characteristic curve of the filter when the decoupling network 200 is not provided in the related art. The abscissa is frequency, and the ordinate is impedance imaginary part. The coupling characteristic of the filter when the decoupling network 200 is not provided is inductive in the Band 1 frequency band and capacitive in the Band 2 frequency band. The inductive coupling formed by the decoupling network 200 can at least partially offset the capacitive coupling of the coupling network 100, and the capacitive coupling formed by the decoupling network 200 can at least partially offset the inductive coupling of the coupling network 100. Curve L1 can be lower than curve L2 at the extreme point of the Band 1 frequency band and higher at the extreme point in the Band 2 frequency band. It can be seen that after the filter is provided with the decoupling network 200, the capacitive or inductive coupling generated by the coupling network 100 can be at least partially offset in the Band 1 frequency band and the Band 2 frequency band, thereby improving the filtering performance of the filter.

[0032] The technical scheme of the embodiment of the present application provides that the decoupling network is connected in parallel with the coupling network formed between the resonator and the sealing structure. At the same frequency, the equivalent impedance value of the decoupling network and the equivalent impedance value of the coupling network are of opposite signs. Thus, at a frequency, the coupling network presents capacitance, and the decoupling network presents inductance; at a frequency, the coupling network presents inductance, and the decoupling network presents capacitance. In this way, the decoupling network can at least partially offset the coupling network formed between the resonator and the sealing structure, thereby eliminating the coupling path formed between the resonator and the sealing structure and improving the filtering performance of the filter.

[0033] FIG. 4 is an equivalent circuit structure diagram of another filter provided by an embodiment of the present application. Optionally, on the basis of the above-mentioned embodiment, refer to FIG. 4. The at least two resonators 300 include at least two series resonators 301, and the at least two series resonators 301 are connected in series between the first port A and the second port B; the decoupling network 200 includes at least two first decoupling networks 201, and each first decoupling network 201 is connected between a series resonator 301 and the ground GND.

[0034] For example, the equivalent impedance of the coupling network 100 is capacitive. The coupling capacitor C11 is an equivalent capacitor formed after the coupling between the series resonator 301 and the sealing structure. The coupling capacitor C12 is an equivalent capacitor formed after the coupling between the other series resonator 301 and the sealing structure.

[0035] The one end of the first decoupling network 201 with an equivalent impedance of L1 is connected with the series resonator 301, and the other end of the first decoupling network 201 with an equivalent impedance of L1 is grounded GND, that is, the first decoupling network 201 with an equivalent impedance of L1 is connected with the coupling capacitor C11 in parallel. The first decoupling network 201 with an equivalent impedance of L1 is inductive, and can at least partially offset the capacitive coupling generated by the coupling capacitor C11. The one end of the first decoupling network 201 with an equivalent impedance of L2 is connected with the series resonator 301, and the other end of the first decoupling network 201 with an equivalent impedance of L2 is grounded GND, that is, the first decoupling network 201 with an equivalent impedance of L2 is connected with the coupling capacitor C12 in parallel. The first decoupling network 201 with an equivalent impedance of L2 is inductive, and can at least partially offset the capacitive coupling generated by the coupling capacitor C12. By adjusting the parameters of the equivalent impedance L1, the coupling path between the first port A and the series resonator 301 can be eliminated, and by adjusting the parameters of the equivalent impedance L2, the coupling path between the second port B and the series resonator 301 can be eliminated, so as to improve the filtering performance of the filter.

[0036] Fig. 5 is a schematic diagram of an equivalent circuit structure of another filter provided by an embodiment of the present application. Optionally, on the basis of the above-mentioned embodiments, referring to Fig. 5. The at least two resonators include a parallel resonator 302, the parallel resonator 302 is connected with a series node, the decoupling network 200 includes a second decoupling network 202, and the second decoupling network 202 is connected between the parallel resonator 302 and the ground GND; wherein the series node includes a first port A, a second port B, and a node C between the first port and the second port connected in series.

[0037] The parallel resonator 302 is connected with the series node, and the series node can be the first port A, the second port B, or the node C between the first port and the second port connected in series. The present embodiment does not limit the number of the series node to which the parallel resonator is connected and the number of the parallel resonators. Exemplarily, Fig. 5 shows that the parallel resonator 302 is connected with the first port A, and other parallel resonators can also be arranged to be connected with the second port B and the node C respectively.

[0038] Taking the case that the equivalent impedance of the coupling network 100 is capacitive. The coupling capacitor C13 is the equivalent capacitor formed after the coupling between the parallel resonator 302 and the sealed structure, and the coupling capacitor C14 is the equivalent capacitor formed after the coupling between another parallel resonator 302 and the sealed structure. One end of the second decoupling network 202 is connected with the parallel resonator 302, and the other end of the second decoupling network 202 is grounded GND, that is, the second decoupling network 202 with the equivalent impedance L3 is connected in parallel with the coupling capacitor C13, and the second decoupling network 202 with the equivalent impedance L4 is connected in parallel with the coupling capacitor C14. The second decoupling network 201 with the equivalent impedance L3 is inductive, and can at least partially offset the capacitive coupling generated by the coupling capacitor C13; the second decoupling network 201 with the equivalent impedance L4 is inductive, and can at least partially offset the capacitive coupling generated by the coupling capacitor C14. By adjusting the parameters of the equivalent impedances L3 and L4, the coupling path between the resonator and the parallel resonator 302 can be eliminated, so as to improve the filtering performance of the filter.

[0039] FIG. 6 is a schematic diagram of an equivalent circuit structure of another filter provided by an embodiment of the present application. Based on the above-mentioned embodiments, referring to FIG. 6. Taking the case that the equivalent impedance of the coupling network 100 is capacitive. The first decoupling network 201 can also be a structure composed of an equivalent capacitor and an equivalent inductor in series. The coupling capacitor C11 is the equivalent capacitor formed after the coupling between one of the series resonators 301 and the sealed structure, and the coupling capacitor C12 is the equivalent capacitor formed after the coupling between another series resonator 301 and the sealed structure. The first decoupling network 201 connected in parallel with the coupling capacitor C11 can be a structure composed of an equivalent capacitor C21 and an equivalent inductor L21 in series, and the first decoupling network 201 connected in parallel with the coupling capacitor C12 can be a structure composed of an equivalent capacitor C22 and an equivalent inductor L22 in series. By adjusting the equivalent capacitor value and the equivalent inductor value, the first decoupling network 201 at least partially offsets the equivalent impedance of the coupling network 100 connected in parallel therewith, so as to improve the filtering effect of the filter.

[0040] Fig. 7 is a schematic diagram of another filter transmission characteristic curve provided by the embodiment of the present application; and Fig. 8 is an enlarged schematic diagram of the filter transmission characteristic curve in the adjacent band shown in Fig. 7. Based on the above embodiment, refer to Figs. 7 and 8. In Fig. 7, curve L1 is the transmission characteristic curve of the filter when the decoupling network 200 is provided in Fig. 6, and curve L2 is the transmission characteristic curve of the filter when the decoupling network 200 is not provided in Fig. 2. The horizontal axis is frequency, and the vertical axis is the imaginary part of impedance. The extreme points M1, M2, M3, M4 and M5 of the transmission characteristic curve of curve L1 in the adjacent band range are lower than the extreme points M6, M7, M8, M9 and M10 of the transmission characteristic curve of curve L2 in the adjacent band range. Therefore, the filter after the decoupling network 200 is provided can improve the adjacent band rejection degree by 3 to 4 dB, eliminate the coupling path between the resonator 300 and the sealing structure, and thus improve the filtering performance of the filter.

[0041] Fig. 9 is a schematic diagram of an equivalent circuit structure of another filter provided by the embodiment of the present application. Based on the above embodiment, refer to Fig. 9, taking the case that the equivalent impedance of the filter including the series resonator 301 and the parallel resonator 302 and the coupling network 100 is capacitive as an example. The filter can include a first decoupling network 201 and a second decoupling network 202. The first decoupling network 201 and the second decoupling network 202 can be a network structure composed of equivalent capacitance and equivalent inductance. By adjusting the equivalent capacitance value and the equivalent inductance value, the first decoupling network 201 at least partially offsets the equivalent impedance of the coupling network 100 corresponding to the series resonator 301 connected in parallel thereto, and the second decoupling network 202 at least partially offsets the equivalent impedance of the coupling network 100 corresponding to the parallel resonator 302 connected in parallel thereto, so as to improve the filtering effect of the filter.

[0042] Optionally, the decoupling network 200 includes a first conductive structure 203, one end of the first conductive structure 203 is connected with the resonator, and the other end is connected with the ground GND.

[0043] The equivalent impedance of the first conductive structure 203 is inductive. One end of the first conductive structure 203 is connected with the resonator 300, and the other end is grounded GND, that is, the first conductive structure 203 is connected in parallel with the coupling network 100 formed between the resonator 300 and the sealing structure 400. When the coupling network 100 is capacitive, the first conductive structure 203 with the introduced equivalent impedance in inductive can at least partially offset the capacitive coupling network 100 formed between the resonator 300 and the sealing structure 400, so as to improve the performance of the filter.

[0044] Optionally, the first conductive structure 203 includes an inductive element or a connecting wire.

[0045] The first conductive structure 203 can be an inductive element, or a connecting wire capable of presenting an inductive impedance, so that the equivalent impedance of the first conductive structure 203 is inductive, at least partially offsetting the capacitive coupling network formed between the resonator 300 and the sealing structure 400.

[0046] Fig. 10 is a structural schematic diagram of a filter provided by an embodiment of the present application. Optionally, on the basis of the above-mentioned embodiment, referring to Figs. 9 and 10, the decoupling network 200 further comprises a capacitive element, a first end of the capacitive element being connected with the first conductive structure 203, and a second end of the capacitive element being connected with the resonator or the ground GND.

[0047] The decoupling network 200 can further comprise a capacitive element. A first end of the capacitive element is connected with the first conductive structure 203 whose equivalent impedance is inductive, and a second end of the capacitive element is connected with the resonator or the ground GND. That is, the decoupling network 200 can be an LC electromagnetic network composed of the first conductive structure 203 and the capacitive element.

[0048] Optionally, on the basis of the above-mentioned embodiment, referring to Fig. 10, the capacitive element comprises a second conductive structure 220 and a third conductive structure 230, a first end of the second conductive structure 220 is connected with the first conductive structure 203, an end surface of a second end of the second conductive structure 220 is arranged opposite to an end surface of a first end of the third conductive structure 230, and a second end of the third conductive structure 230 is connected with the resonator or the ground GND.

[0049] The end surface of the second end of the second conductive structure 220 is arranged opposite to the end surface of the first end of the third conductive structure 230, so as to be equivalent to a capacitor C, and the first conductive structure 203 is equivalent to an inductor L, so that the decoupling network 200 can be an LC electromagnetic network composed of the first conductive structure 203 and the capacitive element. The decoupling network 200 composed of the first conductive structure 203 and the capacitive element is connected in parallel with the coupling network 100, and the decoupling network 200 at least partially offsets the coupling network 100, so as to improve the filtering performance of the filter.

[0050] Optionally, on the basis of the above-mentioned embodiment, referring to Fig. 10, the end surface of the second end of the second conductive structure 220 and the end surface of the first end of the third conductive structure 230 are concave-convex structures; the end surface of the second end of the second conductive structure 220 and the end surface of the first end of the third conductive structure 230 are arranged in a concave-convex staggered manner, and a gap is arranged between the end surface of the second end of the second conductive structure 220 and the end surface of the first end of the third conductive structure 230.

[0051] The end surface of the second end of the second conductive structure 220 is equivalent to a capacitor plate on one side of the coupling capacitor C, and the end surface of the first end of the third conductive structure 230 is equivalent to a capacitor plate on the other side of the coupling capacitor C. The end surface of the second end of the second conductive structure 220 and the end surface of the first end of the third conductive structure 230 can be a jagged concave-convex structure, so that the end surface of the second end of the second conductive structure 220 and the end surface of the first end of the third conductive structure 230 are staggered and arranged in a concave-convex manner, and a gap is reserved, thereby enhancing the coupling effect between the second conductive structure 220 and the third conductive structure 230.

[0052] Optionally, on the basis of the above-mentioned embodiments, referring to FIG. 10, the gap includes a dielectric layer 204, which is used to adjust the capacitance value of the capacitive element.

[0053] The gap between the end surface of the second end of the second conductive structure 220 and the end surface of the first end of the third conductive structure 230 can be provided with a dielectric layer 204, so as to adjust the equivalent capacitance value of the coupling capacitor C, thereby changing the coupling parameter of the decoupling network 200.

[0054] FIG. 11 is a structural schematic diagram of a multiplexer provided by an embodiment of the present application. The multiplexer includes the filter provided by any of the embodiments of the present application.

[0055] The multiplexer includes a first end IN and at least two second ends; each filter is connected in series between the first end IN of the multiplexer and any second end. In FIG. 11, the multiplexer is exemplarily shown to include a first end IN and n second ends, OUT1, OUT2, …, OUTn. Each filter is connected in series between the first end IN and a second end. For example, the first filter 100 is connected in series between the first end IN and the first second end OUT1, the second filter 100 is connected in series between the first end IN and the first second end OUT2, and so on. Since the multiplexer has the filter provided by any of the embodiments of the present application, details are not described herein.

[0056] It should be noted that the multiplexer can also include other filters connected in series between the first end IN and any second end. The other filters can be low-pass filters, high-pass filters or band-pass filters, which are not limited by the embodiments of the present application.

[0057] It should be understood that the above-mentioned various forms of flow can be reordered, added or deleted. For example, the steps described in the present application can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solutions of the present application can be achieved, which are not limited herein.

Claims

1. A filter comprising a sealing structure, a decoupling network and at least two resonators, the sealing structure being arranged around the at least two resonators and being grounded, the decoupling network being connected between the resonators and the ground, the at least two resonators being connected between a first port and a second port of the filter, the resonators and the ground having a coupling network therebetween, the equivalent impedance value of the decoupling network and the equivalent impedance value of the coupling network being of opposite signs at the same frequency.

2. The filter of claim 1, wherein, The at least two resonators comprise at least two series resonators, the at least two series resonators being connected in series between the first port and the second port, the decoupling network comprising at least two first decoupling networks, each of the first decoupling networks being connected between one of the series resonators and the ground.

3. The filter of claim 1 or 2, wherein, The at least two resonators comprise a parallel resonator connected with a series node, the decoupling network comprising a second decoupling network connected between the parallel resonator and the ground, wherein the series node comprises a node between the first port, the second port and the series resonators connected in series between the first port and the second port.

4. The filter of claim 1, wherein, The decoupling network comprises a first conductive structure, one end of the first conductive structure being connected with the resonator and the other end being connected with the ground.

5. The filter of claim 4, wherein, The first conductive structure comprises an inductive element or a connecting wire.

6. The filter of claim 4, wherein, The decoupling network further comprises a capacitive element, a first end of the capacitive element being connected with the first conductive structure and a second end of the capacitive element being connected with the resonator or the ground.

7. The filter of claim 6, wherein, The capacitive element comprises a second conductive structure and a third conductive structure, a first end of the second conductive structure being connected with the first conductive structure, an end surface of a second end of the second conductive structure being arranged opposite to an end surface of a first end of the third conductive structure, and a second end of the third conductive structure being connected with the resonator or the ground.

8. The filter according to claim 7, wherein the end surface of the second end of the second conductive structure and the end surface of the first end of the third conductive structure are concave-convex structures. The end surface of the second end of the second conductive structure and the end surface of the first end of the third conductive structure are arranged staggered with concave-convex structures, and a gap is arranged between the end surface of the second end of the second conductive structure and the end surface of the first end of the third conductive structure.

9. The filter of claim 8, wherein, The gap comprises a dielectric layer arranged therebetween, the dielectric layer being used to adjust the capacitance value of the capacitive element.

10. A multiplexer comprising the filter according to any one of claims 1-9, a first port and at least two second ports, the filter being connected in series between the first port and any one of the second ports.

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