CN112002979A - Filtering power divider and communication system - Google Patents

Abstract

The embodiment of the application discloses a filtering power divider and a communication system, wherein the filtering power divider is of a multilayer structure, the multilayer structure comprises a first substrate layer and a second substrate layer, a first metal layer is arranged between the first substrate layer and the second substrate layer, a microstrip line layer is arranged on the upper side of the first substrate layer, and a second metal layer is arranged on the lower side of the second substrate layer; the microstrip line layer adopts a step impedance Wilkinson power divider structure, and the first metal layer, the second substrate layer and the second metal layer are provided with substrate integrated defect ground structure resonance units with three-dimensional structures. By adopting the technical scheme provided by the embodiment of the application, the wide stop band and the low radiation loss of the filter power divider can be realized at the same time.

Description

A filter power divider and communication system

technical field

The present application relates to the field of communication technologies, and in particular, to a filtering power divider and a communication system.

Background technique

With the development of communication technology, the increase of the working frequency band of the communication system leads to the increase of unnecessary spurious signals received by the communication system, which makes the modern communication system have strong suppression of out-of-band signals. At the same time, the improvement of the integration level of the communication system also requires the passive devices in the communication system to generate lower radiation when working, reducing the influence of electromagnetic radiation on other parts of the communication system, thereby improving the electromagnetic compatibility of the communication system.

The filter power divider is a power divider with filter characteristics, because it has both filter characteristics and power distribution characteristics, and has a wide range of uses. Therefore, the filter power divider with good out-of-band spurious signal suppression function and low radiation loss can greatly reduce the complexity of the communication system and simplify the design. Among the existing wide stopband filter power dividers, many designs use defective ground structure (DGS) to generate slow wave effects, suppress higher harmonics, and achieve wide stopband performance. However, the defective ground structure will produce large radiation loss, which is not conducive to integration in complex communication systems. In addition, some filter power dividers use the substrate integrated waveguide (SIW) method to reduce radiation loss, but cannot produce a wide stopband effect.

SUMMARY OF THE INVENTION

The embodiments of the present application provide a filtering power divider and a communication system, so as to help solve the problem that the filtering power divider in the prior art cannot simultaneously achieve a wide stopband and low radiation loss.

In a first aspect, an embodiment of the present application provides a filtering power divider, the filtering power divider is a multi-layer structure, the multi-layer structure includes a first substrate layer and a second substrate layer, and the first substrate layer A first metal layer is arranged between the first substrate layer and the second substrate layer, a microstrip line layer is arranged on the upper side of the first substrate layer, and a second metal layer is arranged on the lower side of the second substrate layer;

The microstrip line layer adopts a step-impedance Wilkinson power divider structure, and the first metal layer, the second substrate layer and the second metal layer are provided with a substrate-integrated defect structure resonance unit of a three-dimensional structure.

Preferably, the step impedance Wilkinson power divider includes an input unit, a first output unit and a second output unit, and the input unit is respectively connected with the first output unit and the second output unit through a microstrip line, so The first output unit and the second output unit are connected through an isolation resistor.

Preferably, the input unit includes a first T-shaped microstrip line, the first T-shaped microstrip line includes a longitudinal microstrip line and a transverse microstrip line, and one end of the longitudinal microstrip line is connected to the transverse microstrip line. The free end of the vertical microstrip line is used as an input port, and the two ends of the horizontal microstrip line are respectively connected to the first output unit and the second output unit.

Preferably, the first output unit includes a second T-shaped microstrip line and a third T-shaped microstrip line, and the second T-shaped microstrip line and the third T-shaped microstrip line respectively include a lateral microstrip line and a longitudinal microstrip line, the longitudinal microstrip lines of the second T-shaped microstrip line and the third T-shaped microstrip line are arranged close to each other, and the second T-shaped microstrip line and the third T-shaped microstrip line The lateral microstrip lines are set away from each other;

The second output unit includes a fourth T-shaped microstrip line and a fifth T-shaped microstrip line, and the fourth T-shaped microstrip line and the fifth T-shaped microstrip line respectively include a horizontal microstrip line and a vertical microstrip line. Microstrip lines, the vertical microstrip lines of the fourth T-shaped microstrip line and the fifth T-shaped microstrip line are arranged close to each other, and the lateral microstrip lines of the fourth T-shaped microstrip line and the fifth T-shaped microstrip line are arranged close to each other. The strip lines are set away from each other;

The free end of the transverse microstrip line of the second T-shaped microstrip line is the first output port, the free end of the transverse microstrip line of the fifth T-shaped microstrip line is the second output port, and the third T-shaped microstrip line is the second output port. The free end of the lateral microstrip line of the microstrip line and the free end of the lateral microstrip line of the fourth T-shaped microstrip line are connected through an isolation resistor.

Preferably, microstrip open stubs are provided on the second T-shaped microstrip line and/or the fifth T-shaped microstrip line.

Preferably, a transmission zero is provided on the high frequency side of the passband.

Preferably, a metallized via hole is also included, and the metallized via hole penetrates the multi-layer structure.

Preferably, the number of the metallized vias is one or more than one, the metallized vias are arranged around the defect area of the first metal layer, the metallized vias, the second substrate layer and the The second metal layers collectively form an encapsulation of the defective area.

Preferably, the first metal layer includes four defect regions, and the four defect regions are sequentially connected with the second T-shaped microstrip line, the third T-shaped microstrip line, the fourth T-shaped microstrip line and the fifth T-shaped microstrip line. The microstrip lines are set relative to each other.

In a second aspect, an embodiment of the present application provides a communication system, where the communication system includes the filtering power divider according to any one of the first aspect above.

The filtering power divider and the communication system provided by the implementation of this application have the following advantages:

1. Based on the fundamental frequency resonance characteristics of the self-packaged defective ground resonance unit, the filtering characteristics of the filtering power divider can be realized. In addition, the introduction of the microstrip line as the feeder can suppress the higher harmonics of the fundamental frequency signal, so as to achieve a wide stopband and better stopband suppression. At the same time, because the defect area is encapsulated and the complete ground plane structure, the filter power divider is easier to integrate into the communication system, and generates less radiation during operation.

2. Step impedance Wilkinson power divider can realize impedance matching of filter power divider ports and better isolation between output ports. Using the folded step impedance line structure can minimize the size of the power divider and reduce the cost.

3. The T-shaped microstrip line is introduced as the input feeder, and its capacitive load effect can push the fundamental frequency to the low frequency and suppress the high frequency harmonics, further optimizing the stop-band characteristics and reducing the size of the resonant unit.

4. Microstrip open-circuit branches are added on the T-shaped feeders of the two output ports, and a transmission zero is added on the high-frequency side of the passband, which can improve the selectivity of the passband.

Description of drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. In other words, other drawings can also be obtained based on these drawings without creative labor.

FIG. 1 is a schematic three-dimensional structure diagram of a filter power divider provided by an embodiment of the present application;

2 is a schematic cross-sectional view of a filter power divider provided by an embodiment of the present application;

3 is a schematic plan view of a filtering power divider provided by an embodiment of the present application;

4 is a schematic diagram of a simulation and test frequency response of a filter power divider according to an embodiment of the present application;

The symbols in the figure are represented as: 100-first substrate layer, 200-second substrate layer, 300-first metal layer, 301-slow wave resonance unit, 400-second metal layer, 500-microstrip line layer, 510 - input unit, 511 - first T-shaped microstrip line, 520 - first output unit, 521 - second T-shaped microstrip line, 522 - third T-shaped microstrip line, 523 - microstrip open stub, 530 - The second output unit, 531-fourth T-shaped microstrip line, 532-fifth T-shaped microstrip line, 533-microstrip open branch, 600-metallized via, R-isolation resistor.

Detailed ways

In order to make those skilled in the art better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described The embodiments are only a part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the scope of protection of the present application.

The following is an explanation of terms involved in the embodiments of the present application.

DGS (Defected Ground Structure) defective ground structure;

SIDGS (Substrate Integrated DGS) substrate integrated defect structure;

SIW (Substrate Integrated Waveguide) substrate integrated waveguide;

HMT/DGS (Hybrid Microstrip T-stub/DGS) hybrid microstrip/defect structure;

Microstrip microstrip line;

The slow-wave effect is a physical characteristic, which can push the higher harmonics of the fundamental frequency signal of the filter to a higher frequency, resulting in a good harmonic suppression function and realizing a wide stopband. At the same time, the slow wave effect can also reduce the area of the filter power divider, and reduce the cost of the filter power divider while realizing miniaturization.

Existing wide stopband filter power dividers usually include two types: one is to use defective ground structure (DGS) to generate slow wave effect, suppress high-order harmonics, and achieve wide stopband performance, but the defective ground structure will produce relatively poor performance. Large radiation loss is not conducive to integration in complex communication systems; the other is to use substrate integrated waveguide (SIW) to reduce radiation loss, but it cannot produce a wide stopband effect.

Aiming at the problem that the filter power divider in the prior art cannot simultaneously achieve wide stopband and low radiation loss, the embodiments of the present application provide a filter power divider and a communication system, which are described in detail below with reference to the accompanying drawings.

FIG. 1 is a schematic three-dimensional structural diagram of a filtering power divider provided by an embodiment of the present application, FIG. 2 is a schematic cross-sectional view of a filtering power divider provided by an embodiment of the present application, and FIG. 3 is a schematic diagram of a filtering power divider provided by an embodiment of the present application. A schematic plan view of a filtering power divider, as shown in FIG. 1 to FIG. 3 , the filtering power divider provided by the embodiment of the present application includes a first substrate layer 100 and a second substrate layer 200 , the first substrate layer 100 and the second substrate layer 100 A first metal layer 300 is provided between the substrate layers 200, a microstrip line layer 500 is provided on the upper side of the first substrate layer 100, and a second metal layer 400 is provided on the lower side of the second substrate layer 200; The microstrip line layer 500 adopts a step impedance Wilkinson power divider structure. The first metal layer 300, the second metal layer 400, and the second substrate layer 200 are provided with a slow-wave resonance unit 301 with a substrate integrated defect structure. .

It can be understood that, in the multi-layer structure, a partial region of the first metal layer 300 is removed by complete metal to form a defect structure, that is, a defect structure DGS is formed. The second metal layer 400 is a complete piece of metal and serves as a reference ground for the structure. Meanwhile, the second metal layer 400 and the second substrate layer 200 together constitute a substrate-integrated package with a defective structure. The first metal layer 300 , the second substrate layer 200 and the second metal layer 400 form a substrate-integrated defect-ground structure SIDGS.

In the embodiment of the present application, the microstrip line and the defect area of the first metal layer produce slow-wave characteristics, which pushes the higher harmonics of the fundamental frequency signal to high frequencies, so as to achieve a wide stopband and better stopband suppression. . In addition, due to the existence of the second metal layer, the radiation loss of the defectively structured DGS itself is better suppressed. The step impedance Wilkinson power divider can realize impedance matching of the filter power divider port and better isolation between the output ports. Using the folded step impedance line structure can minimize the size of the power divider and reduce the cost.

Specifically, the step-impedance Wilkinson power divider in the filtering power divider provided in the embodiment of the present application includes one input unit 510 and two output units. For the convenience of description, the two output units are respectively defined as the first An output unit 520 and a second output unit 530, the input unit 510 is respectively connected to the first output unit 520 and the second output unit 530 through a microstrip line, and the connection between the first output unit 520 and the second output unit 530 connected through the isolation resistor R. The input unit 510 includes a first T-shaped microstrip line 511, the first T-shaped microstrip line 511 includes a vertical microstrip line and a horizontal microstrip line, and one end of the vertical microstrip line is connected to the horizontal microstrip line. The free end of the vertical microstrip line is used as the input port (port 1 shown in the figure), and the two ends of the horizontal microstrip line are respectively connected with the first output unit 520 and the second output unit 530 connected.

In the embodiment of the present application, a T-shaped microstrip line is introduced as an input feeder, and its capacitive load effect can push the fundamental frequency to low frequencies and the harmonics to high frequencies, further optimizing the stop-band characteristics and reducing the size of the resonance unit .

In an optional embodiment, the first output unit 520 includes a second T-shaped microstrip line 521 and a third T-shaped microstrip line 522, and the second T-shaped microstrip line 521 and the third T-shaped microstrip line 521 The microstrip lines 522 respectively include a horizontal microstrip line and a vertical microstrip line. The vertical microstrip lines of the second T-shaped microstrip line 521 and the third T-shaped microstrip line 522 are arranged close to each other. The lateral microstrip lines of the T-shaped microstrip line 521 and the third T-shaped microstrip line 522 are arranged away from each other;

The second output unit 530 includes a fourth T-shaped microstrip line 531 and a fifth T-shaped microstrip line 532. The fourth T-shaped microstrip line 531 and the fifth T-shaped microstrip line 532 respectively include a lateral microstrip line. strip line and a longitudinal microstrip line, the longitudinal microstrip lines of the fourth T-shaped microstrip line 531 and the fifth T-shaped microstrip line 532 are arranged close to each other, the fourth T-shaped microstrip line 531 and the fifth T-shaped microstrip line 532 are arranged close to each other. The transverse microstrip lines of the T-shaped microstrip line 532 are arranged away from each other; the free end of the transverse microstrip line of the second T-shaped microstrip line 521 is the first output port (port 2 shown in the drawing), the The free end of the transverse microstrip line of the fifth T-shaped microstrip line 532 is the second output port (port 3 shown in the drawing), and the free end of the transverse microstrip line of the third T-shaped microstrip line 522 and the The free ends of the lateral microstrip lines of the fourth T-shaped microstrip line 531 are connected through an isolation resistor R. Microstrip open branches 523 and 533 are provided on the second T-shaped microstrip line 521 and/or the fifth T-shaped microstrip line 532 . Optionally, a transmission zero is provided on the high frequency side of the passband.

In the embodiment of the present application, the first metal layer 300 includes four slow-wave resonance units 301, and the four slow-wave resonance units 301 are connected to the second T-shaped microstrip line 521 and the third T-shaped microstrip line in sequence. 522 , the fourth T-shaped microstrip line 531 and the fifth T-shaped microstrip line 532 are disposed opposite to each other.

In an optional embodiment, a metallized via hole 600 is further provided on the multi-layer structure, and the metallized via hole 600 penetrates the multi-layer structure. Preferably, the number of the metallized vias 600 is one or more than one, and the metallized vias 600 are arranged around the defect area. The metallized vias 600 disposed around the defect area can reduce the radiation level of the first metal layer 300, thereby reducing the impact on other devices used in the communication body.

In the embodiment of the present application, a microstrip open-circuit branch is added on the T-shaped feeder of the two output ports, and a transmission zero is added on the high-frequency side of the passband, which can improve the selectivity of the passband.

In a specific implementation, the center frequency of the filter power divider is determined by the physical size of the structure. For example, increasing w ₁ , 1 ₃ , 1 ₄ , 1 ₅ , 1 ₆ , 1 ₇ can reduce the center frequency; the bandwidth of the filter power divider can be adjusted by adjusting d ₁ , d ₂ ; increasing d ₁ , Decreasing _d2 increases the filter bandwidth. At the same time, the input impedance of port 1 is affected by w ₄ , w ₅ , 1 ₈ , and 1 ₉ . By changing these parameters, the return loss of port 1 can be reduced and the impedance matching effect can be achieved. At the same time, changing the resistance value of the isolation resistor R will affect the impedance matching of port 2 and port 3 and the isolation between the ports. Selecting the appropriate isolation resistor R can achieve better impedance matching and isolation of the output ports.

FIG. 4 is a schematic diagram of the simulation and test frequency response of a filter power divider provided by the embodiment of the application, and the filter power divider adopted in FIG. 4 uses an RO4003C high-frequency board (relative dielectric constant 3.55, thickness h ₁ is 0.203mm , the thickness h2 is _0.303mm ) and tested. The simulation and test results of the filter power divider are shown in Figure 4. The center frequency of the passband is 2.9GHz, the minimum passband insertion loss is 1.0dB, and the isolation is greater than 20dB. The stopband can be extended to 25GHz under the premise of low radiation loss, which is 8.71 times of the fundamental frequency signal, and the rejection of the stopband reaches -28dB. The isolation of the stop band is greater than 25dB, which realizes the effect of broadband isolation.

Based on the above power divider, an embodiment of the present application further provides a communication system, where the communication system includes the power divider shown in the above embodiment.

It should be noted that, in this document, relational terms such as "first" and "second" etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply these There is no such actual relationship or sequence between entities or operations. Moreover, the terms "comprising", "comprising" or any other variation thereof are intended to encompass a non-exclusive inclusion such that a process, method, article or device that includes a list of elements includes not only those elements, but also includes not explicitly listed or other elements inherent to such a process, method, article or apparatus. Without further limitation, an element qualified by the phrase "comprising a..." does not preclude the presence of additional identical elements in a process, method, article or apparatus that includes the element.

The above descriptions are only specific embodiments of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

It is sufficient to refer to each other for the same and similar parts among the various embodiments in this specification. In particular, for the terminal embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and for related parts, please refer to the description in the method embodiment.

The above-described embodiments of the present application do not limit the protection scope of the present application.

Claims (10)

1. A filter power divider, characterized in that the filter power divider is a multi-layer structure, and the multi-layer structure comprises a first substrate layer and a second substrate layer, the first substrate layer and the second substrate A first metal layer is arranged between the layers, a microstrip line layer is arranged on the upper side of the first substrate layer, and a second metal layer is arranged on the lower side of the second substrate layer; The microstrip line layer adopts a step-impedance Wilkinson power divider structure, and the first metal layer, the second substrate layer and the second metal layer are provided with a substrate-integrated defect structure resonance unit of a three-dimensional structure. 2. The filtering power divider according to claim 1, wherein the step impedance Wilkinson power divider comprises an input unit, a first output unit and a second output unit, and the input unit passes through a microstrip The lines are respectively connected to the first output unit and the second output unit, and the first output unit and the second output unit are connected through an isolation resistor. 3. The filtering power divider according to claim 2, wherein the input unit comprises a first T-shaped microstrip line, and the first T-shaped microstrip line comprises a vertical microstrip line and a horizontal microstrip line , one end of the vertical microstrip line is connected to the horizontal microstrip line, the free end of the vertical microstrip line is used as an input port, and the two ends of the horizontal microstrip line are respectively connected to the first output unit and the second The two output units are connected. 4. filter power divider according to claim 2, is characterized in that, The first output unit includes a second T-shaped microstrip line and a third T-shaped microstrip line, and the second T-shaped microstrip line and the third T-shaped microstrip line respectively include a horizontal microstrip line and a vertical microstrip line. Microstrip lines, the vertical microstrip lines of the second T-shaped microstrip line and the third T-shaped microstrip line are arranged close to each other, and the lateral microstrip lines of the second T-shaped microstrip line and the third T-shaped microstrip line are arranged close to each other. The strip lines are set away from each other; The second output unit includes a fourth T-shaped microstrip line and a fifth T-shaped microstrip line, and the fourth T-shaped microstrip line and the fifth T-shaped microstrip line respectively include a horizontal microstrip line and a vertical microstrip line. Microstrip lines, the vertical microstrip lines of the fourth T-shaped microstrip line and the fifth T-shaped microstrip line are arranged close to each other, and the lateral microstrip lines of the fourth T-shaped microstrip line and the fifth T-shaped microstrip line are arranged close to each other. The strip lines are set away from each other; The free end of the transverse microstrip line of the second T-shaped microstrip line is the first output port, the free end of the transverse microstrip line of the fifth T-shaped microstrip line is the second output port, and the third T-shaped microstrip line is the second output port. The free end of the lateral microstrip line of the microstrip line and the free end of the lateral microstrip line of the fourth T-shaped microstrip line are connected through an isolation resistor. 5 . The filtering power divider according to claim 4 , wherein the second T-shaped microstrip line and/or the fifth T-shaped microstrip line is provided with a microstrip open-circuit branch. 6 . 6 . The filter power divider according to claim 4 , wherein a transmission zero is provided on the high frequency side of the passband. 7 . 7 . The filtering power divider of claim 4 , further comprising metallized vias, the metallized vias penetrating the multi-layer structure. 8 . 8 . The filter power divider according to claim 7 , wherein the number of the metallized vias is one or more than one, and the metallized vias surround the defects of the first metal layer. 9 . The area is arranged, and the metallized via hole, the second substrate layer and the second metal layer together form the package of the defect area. 9 . The filtering power divider according to claim 2 , wherein the first metal layer comprises four defect regions, and the four defect regions are connected to the second T-shaped microstrip line and the third T-shaped microstrip line in sequence. 10 . The microstrip line, the fourth T-shaped microstrip line and the fifth T-shaped microstrip line are arranged oppositely. 10. A communication system, characterized by comprising the filtering power divider according to any one of claims 1-8.

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