Miniaturized filtering power divider loaded with novel isolation network

Abstract

The invention discloses a miniaturized filtering power divider loaded with a novel isolation network, and particularly relates to the technical field of wireless microwaves, and the miniaturized filtering power divider comprises spiral inductors, chip capacitors, ports, a reference metal ground, a dielectric substrate, isolation resistors, metal through holes and gold wire connecting wires, a signal path of the filtering power divider is arranged between the first port and the second port, between the first port and the third port, and between the second port and the third port. And a novel isolation network is adopted, so that the isolation degree between the second port and the third port becomes higher. The filter has the advantages of being small in size, easy to integrate, good in isolation and the like, a passband of the filter is a broadband, three transmission poles exist in the passband, an upper stop band of the filter has a transmission zero point, a lower stop band of the filter has a transmission zero point, and the filter has the characteristics of filtering and power dividing at the same time.

Description

Technical Field

[0001] The invention relates to the field of wireless microwave technology, and in particular to a miniaturized filtering power divider loaded with a novel isolation network. Background Art

[0002] With the development of wireless communication technology, microwave passive devices have been more widely used, and the increasingly complex application scenarios have also put forward higher requirements for microwave passive devices. The performance of the device directly affects the quality of the communication system. Filters and power dividers (referred to as power dividers) are important components of wireless communication systems and are widely used in wireless communication systems. The function of the filter is to filter signals of specific frequencies and suppress stray signals of other frequencies. According to the different frequency responses, it can be divided into bandpass, bandstop, low-pass and high-pass filters. It is widely used in mobile phones, wireless broadcasting, satellite reception, vehicle communications, wireless control and other fields. The function of the power divider is to distribute and synthesize power. It can distribute the input signal into multiple signals in proportion, and requires a certain isolation between the output ports to avoid mutual interference between the output signals. Common power dividers include T-junction power dividers, Gysel power dividers and Wilkinson power dividers, which are widely used in microwave circuits such as antenna arrays, frequency multipliers, and mixers. In most application scenarios, filters and power dividers are often used in circuits in a cascade manner. Although this achieves the purpose of filtering characteristics and power distribution, it also increases the cascade connection lines between devices, accompanied by unnecessary insertion losses, and the two independent devices inevitably take up more space, which is not conducive to the miniaturization requirements of today's communication systems.

[0003] In order to achieve high integration, miniaturization and multifunctionality of devices, a filter power divider that integrates the performance of filters and power dividers has been proposed, and has good application prospects in wireless communication systems. However, the current filter power divider still has many areas that need to be improved, such as the circuit performance of the filter power divider is not ideal, the isolation between the output ports is poor, and the device size is large. These defects limit the application of the filter power divider in practical engineering. Therefore, most of the current research focuses on the circuit performance of the filter power divider. These performance parameters include the frequency selection characteristics, out-of-band suppression, output port isolation, insertion loss, etc. of the filter power divider. While meeting the above good circuit characteristics, the research on the filter power divider in the direction of ultra-wideband, multi-channel, multi-passband and miniaturization is also of great engineering significance. On the basis of meeting the good circuit performance of the filter power divider, this paper achieves good isolation between port 2 and port 3 by loading a new type of isolation network, and meets the requirements of miniaturization and easy integration, which has certain practical significance. Summary of the invention

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] A miniaturized filtering power divider loaded with a novel isolation network, characterized in that it comprises: a spiral inductor, a chip capacitor, a second port, a first port, a third port, a reference metal ground, a dielectric substrate, an isolation resistor, a metal through hole and a gold wire connection line;

[0006] The filter power divider has three parts, including a first part, a second part, and a third part. The first part is placed between the first port and the second port; the second part is placed between the first port and the third port; the third part is placed between the second port and the third port;

[0007] The first part comprises a first capacitor and a second capacitor isolated from a port, a third capacitor, a fourth capacitor and a fifth capacitor connected to ground, wherein the fourth capacitor and the fifth capacitor are connected in series; comprises a sixth capacitor and a first inductor connected in series, a seventh capacitor and a second inductor connected in series, a third inductor connected to ground in series, an eighth capacitor and a ninth capacitor, wherein the third inductor is a coupled inductor;

[0008] The second part comprises a tenth capacitor and an eleventh capacitor with port isolation, a twelfth capacitor, a thirteenth capacitor and a fourteenth capacitor connected in series, wherein the thirteenth capacitor and the fourteenth capacitor are connected in series; comprises a fifteenth capacitor and a fourth inductor connected in series, a sixteenth capacitor and a fifth inductor connected in series, a sixth inductor connected in series with a ground, a seventeenth capacitor and an eighteenth capacitor, wherein the sixth inductor is a coupled inductor;

[0009] The third part includes an isolated first resistor connected between the third inductor and the sixth inductor; an isolated second resistor connected between the seventh capacitor and the sixteenth capacitor; and the seventh inductor and the third resistor connected in series are connected between the second port and the third port.

[0010] Preferably, the first inductor, the second inductor, the third inductor, the fourth inductor, the fifth inductor, the sixth inductor and the seventh inductor in the filter power divider all adopt spiral inductors of the same shape. The inductors are not limited to spiral inductors, and three-dimensional inductors, zigzag inductors, etc. may also be adopted.

[0011] Preferably, the first capacitor, the second capacitor, the third capacitor, the fourth capacitor, the fifth capacitor, the sixth capacitor, the seventh capacitor, the eighth capacitor, the ninth capacitor, the tenth capacitor, the eleventh capacitor, the twelfth capacitor, the thirteenth capacitor, the fourteenth capacitor, the fifteenth capacitor, the sixteenth capacitor, the seventeenth capacitor and the eighteenth capacitor in the filtering power divider are chip capacitors, and may also be parallel plate capacitors, interdigitated capacitors, multilayer capacitors, etc.

[0012] Preferably, the first resistor, the second resistor and the third resistor in the filter power divider are square resistors, and may also be thick film resistors or metal film resistors.

[0013] Preferably, the filter power divider has a symmetrical structure from top to bottom, further reducing the types of components.

[0014] Preferably, the filter power divider adopts a thin film ceramic process, but is not limited to the thin film ceramic process, and may also adopt an integrated passive device process, a low temperature co-fired ceramic process, etc.

[0015] In the above technical solution, the technical effects and advantages provided by the present invention are:

[0016] 1. The present invention proposes a miniaturized filtering power divider loaded with a novel isolation network, which adopts three isolation networks of a first resistor, a second resistor, a third resistor in series with a seventh inductor, so that the isolation between the second port and the third port is greatly increased.

[0017] 2. The present invention proposes a miniaturized filter power divider loaded with a new isolation network, which is a bandpass filter power divider with three transmission poles in the passband, and each of the upper stopband and the lower stopband has a transmission zero point, which increases the out-of-band suppression.

[0018] 3. The miniaturized filtering power divider loaded with a novel isolation network proposed in the present invention has the advantages of small size, easy processing, low cost, and easy integration. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0020] Figure 1 A three-dimensional diagram of a miniaturized filter power divider loaded with a novel isolation network;

[0021] Figure 2 A top view of a miniaturized filter power divider loaded with a novel isolation network;

[0022] Figure 3 The circuit diagram of a miniaturized filtering power divider loaded with a new isolation network.

[0023] Figure 4 Performance diagram of a miniaturized filter power divider loaded with a new isolation network.

[0024] Figure 5 Performance diagram of a miniaturized filter power divider loaded with a new isolation network.

[0025] Description of reference numerals:

[0026] 1. The third inductor; 2. The eighth capacitor; 3. The second port; 4. The reference metal ground; 5. The dielectric substrate; 6. The third resistor; 7. The metal through hole; 8. The gold wire connection line; 9. The first port; 10. The third port; 11. The sixth capacitor; 12. The third capacitor; 13. The first capacitor; 14. The second inductor; 15. The seventh capacitor; 16. The fourth capacitor; 17. The fifth capacitor; 18. The second capacitor; 19. The eleventh capacitor; 20. The thirteenth capacitor; 21. The fourteenth capacitor; 22. The sixteenth capacitor; 23. The eighteenth capacitor; 24. The fifth inductor; 25. The sixth inductor; 26. The fourth inductor; 27. The seventeenth capacitor; 28. The fifteenth capacitor; 29. ​​The first resistor; 30. The second resistor; 31. The seventh inductor; ; A. The first part; B. The second part; C. The third part. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0028] The present invention discloses a miniaturized filtering power divider loaded with a novel isolation network, characterized in that it comprises: a third inductor 1, an eighth capacitor 2, a second port 3, a first port 9, a third port 10, a reference metal ground 4, a dielectric substrate 5, a third resistor 6, a metal through hole 7 and a gold wire connection line 8;

[0029] The filter power divider has three parts, including a first part A, a second part B, and a third part C. The first part A is placed between the first port 9 and the second port 3; the second part B is placed between the first port 9 and the third port 10; the third part C is placed between the second port 3 and the third port 10;

[0030] The first part A comprises a first capacitor 13 and a second capacitor 18 with port isolation, a third capacitor 12, a fourth capacitor 16 and a fifth capacitor 17 connected in series, wherein the fourth capacitor 16 and the fifth capacitor 17 are connected in series; comprises a sixth capacitor 11 and a first inductor 9 connected in series, a seventh capacitor 15 and a second inductor 14 connected in series, a third inductor 1 and an eighth capacitor 2 and a ninth capacitor 10 connected in series to ground, wherein the third inductor 1 is a coupled inductor;

[0031] The second part A comprises a tenth capacitor 22 and an eleventh capacitor 19 with port isolation, a twelfth capacitor 22, a thirteenth capacitor 20 and a fourteenth capacitor 21 connected in series, wherein the thirteenth capacitor 20 and the fourteenth capacitor 21 are connected in series; comprises a fifteenth capacitor 28 and a fourth inductor 26 connected in series, a sixteenth capacitor 22 and a fifth inductor 24 connected in series, a sixth inductor 25, a seventeenth capacitor 27 and an eighteenth capacitor 23 connected in series to ground, wherein the sixth inductor 5 is a coupled inductor;

[0032] The third part C includes an isolated first resistor 29 connected between the third inductor 1 and the sixth inductor 25; an isolated second resistor 30 connected between the seventh capacitor 15 and the sixteenth capacitor 22; and a seventh inductor 31 and a third resistor 6 connected in series between the second port 3 and the third port 10.

[0033] The first inductor 9 , the second inductor 14 , the third inductor 1 , the fourth inductor 26 , the fifth inductor 24 , the sixth inductor 25 and the seventh inductor 31 all adopt the same shape of spiral inductor, three-dimensional inductor or broken line inductor.

[0034] The first capacitor 13, the second capacitor 18, the third capacitor 12, the fourth capacitor 16, the fifth capacitor 17, the sixth capacitor 11, the seventh capacitor 15, the eighth capacitor 2, the ninth capacitor 10, the tenth capacitor 22, the eleventh capacitor 19, the twelfth capacitor 22, the thirteenth capacitor 20, the fourteenth capacitor 21, the fifteenth capacitor 28, the sixteenth capacitor 22, the seventeenth capacitor 27 and the eighteenth capacitor 23 all adopt chip capacitors, parallel plate capacitors, interdigitated capacitors or multilayer capacitors.

[0035] The first resistor 29 , the second resistor 30 , and the third resistor 6 are square resistors, thick film resistors, or metal film resistors.

[0036] The filter power divider has a symmetrical structure from top to bottom, which further reduces the types of components.

[0037] The filter power divider is made of thin film ceramic technology, but is not limited to thin film ceramic technology. It can also be made of integrated passive device technology, low temperature co-fired ceramic technology, etc.

[0038] The present invention provides a miniaturized filter power divider loaded with a novel isolation network. The specific circuit diagram of the filter power divider is shown in Figure 3In the circuit diagram, inductor L2 and capacitor C4 control the position of transmission zero TZ1, and inductor L2 and capacitor C5 control transmission zero TZ2. Capacitor C1 and capacitor C8 on the main transmission line affect the return loss of port one, and the resonator frequency of the series inductor L1 and capacitor C3, and the series inductor L3 and C6 determine the center frequency of the filter power divider. Resistors R1, R2, R3 and inductor L7 jointly control port isolation. Because the entire circuit is symmetrical from top to bottom, the return loss of port two is equal to the return loss of port three. Therefore, according to the above rules, the required performance can be quickly debugged through circuit simulation software.

[0039] According to the obtained circuit value, first determine the inductance values ​​of the first inductor 9, the second inductor 14, the third inductor 1, the fourth inductor 26, the fifth inductor 24, the sixth inductor 25 and the seventh inductor 31, use the electromagnetic simulation software to establish the inductance model, and extract the inductance value. Determine the inductance value by adjusting the size of the inductor; According to the obtained circuit value, select the appropriate patch capacitor value, thereby determining the values ​​of the first capacitor 13, the second capacitor 18, the third capacitor 12, the fourth capacitor 16, the fifth capacitor 17, the sixth capacitor 11, the seventh capacitor 15, and the eighth capacitor 2, the ninth capacitor 10, the tenth capacitor 22, the eleventh capacitor 19, the twelfth capacitor 22, the thirteenth capacitor 20, the fourteenth capacitor 21, the fifteenth capacitor 28, the sixteenth capacitor 22, the seventeenth capacitor 27 and the eighteenth capacitor 23, establish the patch capacitor on the electromagnetic simulation software, and optimize the performance by reasonably arranging the positions of the inductors and capacitors and by adjusting the capacitance and inductance values.

[0040] Figure 4 and Figure 5 The performance diagram of electromagnetic simulation is shown. It can be seen from the figure that the circuit simulation results are very consistent with the electromagnetic simulation results. From the electromagnetic simulation performance, it can be seen that the center frequency of the filter power divider is 2.4GHz, the 20-dB return loss relative to the bandwidth is 25%, the return losses of port two and port three are both below -20dB, the stopbands on both sides of the passband are both 20.8dB, and the port isolation in the passband reaches 18.8dB; the above indicators show that the filter power divider has the advantages of high selectivity and high suppression; in addition, the size of the filter power divider is only 5mm×4.6mm.

[0041] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A miniaturized filter power divider loaded with a new isolation network, characterized in that: include: Spiral inductor (1), chip capacitor (2), second port (3), first port (9), third port (10), reference metal ground (4), dielectric substrate (5), isolation resistor (6), metal through hole (7) and gold wire connection line (8); The filter power divider has three parts, including a first part (A), a second part (B), and a third part (C); The first part (A) is placed between the first port (9) and the second port (3); the second part (B) is placed between the first port (9) and the third port (10); the third part (C) is placed between the second port (3) and the third port (10); The first part (A) comprises a first capacitor (13) and a second capacitor (18) with port isolation, a third capacitor (12), a fourth capacitor (16) and a fifth capacitor (17) connected in series, wherein the fourth capacitor (16) and the fifth capacitor (17) are connected in series; the first part (A) comprises a sixth capacitor (11) and a first inductor (9) connected in series, a seventh capacitor (15) and a second inductor (14) connected in series, a third inductor (1) and an eighth capacitor (2) and a ninth capacitor (10) connected in series to ground, wherein the third inductor (1) is a coupled inductor; The second part (A) comprises a tenth capacitor (22) and an eleventh capacitor (19) with port isolation, a twelfth capacitor (22), a thirteenth capacitor (20) and a fourteenth capacitor (21) connected in series, wherein the thirteenth capacitor (20) and the fourteenth capacitor (21) are connected in series; comprises a fifteenth capacitor (28) and a fourth inductor (26) connected in series, a sixteenth capacitor (22) and a fifth inductor (24) connected in series, a sixth inductor (25) and a seventeenth capacitor (27) and an eighteenth capacitor (23) connected in series to ground, wherein the sixth inductor (25) is a coupled inductor; The third part (C) comprises an isolated first resistor (29) connected between the third inductor (1) and the sixth inductor (25); an isolated second resistor (30) connected between the seventh capacitor (15) and the sixteenth capacitor (22); and a seventh inductor (31) and a third resistor (6) connected in series between the second port (3) and the third port (10).

2. According to claim 1, a miniaturized filter power divider loaded with a novel isolation network is characterized in that: The first inductor (9), the second inductor (14), the third inductor (1), the fourth inductor (26), the fifth inductor (24), the sixth inductor (25) and the seventh inductor (31) are all spiral inductors or zigzag inductors of the same shape.

3. According to claim 1, a miniaturized filter power divider loaded with a novel isolation network is characterized in that: The first capacitor (13), the second capacitor (18), the third capacitor (12), the fourth capacitor, the fifth capacitor (17), the sixth capacitor (11), the seventh capacitor (15), the eighth capacitor (2), the ninth capacitor (10), the tenth capacitor (22), the eleventh capacitor (19), the twelfth capacitor (22), the thirteenth capacitor, the fourteenth capacitor (21), the fifteenth capacitor (28), the sixteenth capacitor, the seventeenth capacitor (27) and the eighteenth capacitor (23) are all chip capacitors, parallel plate capacitors or multilayer capacitors.

4. According to claim 1, a miniaturized filter power divider loaded with a novel isolation network is characterized in that: The first resistor (29), the second resistor (30) and the third resistor (6) are all square resistors, thick film resistors or metal film resistors.

5. According to claim 1, a miniaturized filter power divider loaded with a novel isolation network is characterized in that: The filter power divider has a symmetrical structure at the top and the bottom, which further reduces the types of components of the filter power divider.

6. A miniaturized filter power divider loaded with a novel isolation network according to claim 1, characterized in that: The filter power divider adopts a thin film ceramic process, an integrated passive device process or a low temperature co-fired ceramic process.

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