Three-port filtering power divider based on square patch resonators

Abstract

The invention discloses a three-port filtering power divider based on square patch resonators, which comprises a rectangular upper-layer dielectric plate, a lower-layer dielectric plate, a metal floor located between the two dielectric plates and provided with a cross-shaped groove, an input port feeder line located on the upper surface of the upper-layer dielectric plate, an upper-layer square patch resonator and an isolation resistor, the second output port feeder line, the third output port feeder line and the lower-layer square patch resonator are located on the lower surface of the lower-layer dielectric plate. Wherein the input port feeder line, the second output port feeder line and the third output port feeder line comprise a quarter-wavelength resonator and a port 50-ohm microstrip line conduction band; wherein one end of the isolation resistor is connected with the midpoint of one side of the upper-layer square patch resonator through a microstrip line, and the other end of the isolation resistor is connected with the metal floor through a grounding column penetrating through the upper-layer dielectric plate. The invention has the advantages of compact structure, excellent performance, low cost and the like, and is very suitable for modern communication systems.

Description

Technical Field

[0001] The invention relates to the technical field of communication systems, in particular to a three-port filtering power distributor based on square patch resonators. Background Art

[0002] Filters are key components in microwave communication systems and are an indispensable part of today's microwave relay communications, microwave satellite communications and other fields. Their performance has a great impact on the overall quality of the entire communication system. A filter is a filter circuit designed to pass a specific frequency band while attenuating all signals outside the band. In recent years, the development trend of communication systems has been to develop low-cost, low-dimensional, high-performance filters.

[0003] The power divider is one of the basic components of wireless communication systems. It is mainly used to divide the input power evenly or unevenly into several smaller powers. In the 1960s, Wilkinson designed the Wilkinson power divider. He proposed to install a resistor device between the output ports. If the output ends are not matched, the reflected energy generated is absorbed by the resistor, achieving output isolation. Later, the Gysel power divider was proposed in 1975. It changed the isolation structure by introducing two isolation resistors, thereby improving the heat dissipation performance under high power. With the continuous development of communication systems, the design of power dividers has developed towards planar integration, multi-channel power division and broadband. In addition to the development from a single frequency band to multiple frequency bands, the power divider has also developed from a two-way power divider to a four-way, eight-way, and sixteen-way power divider.

[0004] Reference 1 (Wu YL, Hui Z, Zhang YX, et al. An Unequal Wilkinson Power Divider for a Frequency and Its First Harmonic[J]. IEEE Microwave&Wireless Components Letters, 2008, 18(11):737-739) proposed an unequal power divider operating at a certain frequency and the first harmonic. Based on the method of changing the width of the microstrip line to achieve different impedances, four groups of 1 / 6 wavelength transmission lines with different impedances were designed to achieve unequal power division. However, only a fixed power division ratio can be achieved, and it cannot be achieved arbitrarily.

[0005] Reference 2 (Al Shamaileh K, Dib N, Abushamleh S. A dual-band 1: 10Wilkinson power divider based on multi-T-section characterization of high-impedance transmission lines[J]. IEEE Microwave and Wireless Components Letters, 2017, 27(10): 897-899.) proposes a new design method for unequal power dividers. Unlike the traditional method, the characteristic impedance of the designed branch is independent of the power ratio, and unequal division can be achieved by simply adjusting the electrical length of the microstrip line. However, a higher power division ratio cannot be achieved, and only a small power ratio such as 2:1 or 3:1 can be achieved.

[0006] As can be seen from the above, the problems existing in the prior art are: complex design structure, large size, high cost, inconvenient processing; and difficulty in achieving an arbitrary power division ratio. Summary of the invention

[0007] The purpose of the present invention is to provide a three-port filter power divider based on square patch resonators. The present invention has the advantages of compact structure, superior performance, low cost, etc., and is very suitable for modern communication systems.

[0008] The technical solution to achieve the purpose of the present invention is: A three-port filter power distributor based on a square patch resonator comprises a rectangular upper dielectric plate, a metal floor and a rectangular lower dielectric plate stacked in sequence from top to bottom, wherein a "cross" groove is opened in the center of the metal floor; An input port feeder, an upper square patch resonator, and an isolation resistor are provided on the upper surface of the upper dielectric plate. The upper square patch resonator is located at the center of the upper dielectric plate. The input port feeder and the isolation resistor are respectively vertically connected to different sides of the upper square patch resonator. A second output port feeder, a third output port feeder, and a lower square patch resonator are provided on the lower surface of the lower dielectric plate, the lower square patch resonator is located at the center of the lower dielectric plate, and the second output port feeder and the third output port feeder are respectively connected to different sides of the lower square patch resonator; The projection of the upper square patch resonator on the lower surface of the lower dielectric plate coincides with the lower square patch resonator.

[0009] As a further optimization scheme of the present invention, the input port feeder is projected on the lower surface of the lower dielectric plate on the opposite side of the third output port feeder, and the isolation resistor is projected on the lower surface of the lower dielectric plate on the same side of the second output port feeder.

[0010] As a further optimization scheme of the present invention, the input port feed line is located on the left side of the upper square patch resonator, one end is connected to the center of the left side of the upper square patch resonator, and the other end is connected to the center of the left side of the upper dielectric plate.

[0011] As a further optimization scheme of the present invention, the isolation resistor is located on the rear side of the upper square patch resonator, one end of which is connected to the center of the rear side of the upper square patch resonator through a microstrip line, and the other end is connected to the metal floor through a grounding column that passes through the upper dielectric plate.

[0012] As a further optimization scheme of the present invention, the second output port feed line is located at the rear side of the lower square patch resonator, one end is connected to the rear side edge of the lower square patch resonator, and the other end is vertically connected to the rear side edge of the lower dielectric plate.

[0013] As a further optimization scheme of the present invention, the third output port feed line is located on the right side of the lower square patch resonator, one end is connected to the right side of the lower square patch resonator, and the other end is vertically connected to the right side of the lower dielectric plate.

[0014] As a further optimization scheme of the present invention, the input port feeder includes a connected input port 50 ohm microstrip line guide strip and an input port quarter-wavelength transmission line; the second output port feeder includes a connected second output port 50 ohm microstrip line guide strip and an output port quarter-wavelength transmission line, and the third output port feeder includes a connected third output port 50 ohm microstrip line guide strip and an output port quarter-wavelength transmission line.

[0015] As a further optimization solution of the present invention, the 50 ohm microstrip line guide strip of the input port, the 50 ohm microstrip line guide strip of the second output port, and the 50 ohm microstrip line guide strip of the third output port are of the same size.

[0016] As a further optimization solution of the present invention, the upper dielectric plate and the lower dielectric plate have the same size.

[0017] Compared with the prior art, the present invention has the following significant advantages: (1) The present invention has a simple structure and uses a square patch as a resonator, which is easy to process and has a low production cost; (2) The present invention determines two points for feeding by analyzing the electric field distribution of the TM10 mode on a single patch and the field strength, thereby achieving the goal of an arbitrary power division ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a three-dimensional structural schematic diagram of the present invention.

[0019] Figure 2 It is a schematic diagram of the top structure of the present invention.

[0020] Figure 3 It is a top cross-sectional view of the lower surface of the lower dielectric plate of the present invention.

[0021] Figure 4 It is a schematic diagram of the structure and dimensions of the upper dielectric plate in the present invention.

[0022] Figure 5 It is a schematic diagram of the structure and dimensions of the lower dielectric plate in the present invention.

[0023] Figure 6 It is the S parameter simulation diagram of the present invention.

[0024] Figure 7 It is the isolation simulation diagram of the present invention.

[0025] Among them, 1. Metal floor; 11. Cross groove; 2. Upper dielectric plate; 3. Lower dielectric plate; 4. Input port feeder; 41. Input port quarter-wavelength transmission line; 42. Input port 50 ohm microstrip line guide strip; 5. Upper square patch resonator; 6. Isolation resistor; 61. Microstrip line; 62. Grounding column; 7. Output port feeder; 71. Output port quarter-wavelength transmission line; 72. Output port 50 ohm microstrip line guide strip; 8. Output port feeder; 81. Output port quarter-wavelength transmission line; 82. Output port 50 ohm microstrip line guide strip; 9. Lower square patch resonator. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] like Figures 1 to 3As shown, a three-port filter power divider based on a square patch resonator comprises a rectangular upper dielectric plate 2, a lower dielectric plate 3, a metal floor 1 with a "cross" groove 11 located between the two dielectric plates, an input port feeder 4 located on the upper surface of the upper dielectric plate 2, an upper square patch resonator 5, an isolation resistor 6, a second output port feeder 7 located on the lower surface of the lower dielectric plate 3, a third output port feeder 8, and a lower square patch resonator 9, wherein the metal floor 1 is arranged between the upper dielectric plate 2 and the lower dielectric plate 3; the upper square patch resonator 5 is located in the middle of the upper dielectric plate 2, and the input port feeder 4 is located at the center position on the left side of the upper square patch resonator 5. It is vertically connected to the center of the left side of the upper dielectric plate 2; the isolation resistor 6 is located directly behind the upper square patch resonator 5, one end of which is connected to the upper square patch resonator 5 through a microstrip line 61, and the other end is connected to the metal floor 1 through a grounding column 62 that runs through the upper dielectric plate 2; the "cross" groove 11 is located at the exact center of the metal floor 1; the lower square patch resonator 9 is located on the directly lower surface of the lower dielectric plate 3; the second output port feeder 7 is located on the rear side of the lower square patch resonator 9 and vertically connected to the rear side of the lower dielectric plate 3; the third output port feeder 8 is located on the right side of the lower square patch resonator 9 and vertically connected to the right side of the lower dielectric plate 3.

[0028] The input port feeder 4 includes an input port 50 ohm microstrip line guide strip 42 and an input port quarter-wavelength transmission line 41 connected in sequence; the second output port feeder 7 includes a second output port 50 ohm microstrip line guide strip 72 and an output port quarter-wavelength transmission line 71 connected in sequence, and the third output port feeder 8 includes a third output port 50 ohm microstrip line guide strip 82 and an output port quarter-wavelength transmission line 81 connected in sequence.

[0029] The input port 50 ohm microstrip line guide strip 31, the second output port 50 ohm microstrip line guide strip 71, and the third output port 50 ohm microstrip line guide strip 81 have the same size, the upper dielectric plate 2 and the lower dielectric plate 3 have the same size, and the upper square patch resonator 5 and the lower square patch resonator 9 have the same size.

[0030] The present invention is a three-port filter power divider based on a square patch resonator, wherein the size of the upper square patch resonator 5 and the lower square patch resonator 9 determines the center frequency of the present invention, the distance G1 between the second input port quarter-wavelength transmission line 71 and the right side of the lower square patch resonator 9 determines the electric field strength of the second output port, and the distance G2 between the third input port quarter-wavelength transmission line 81 and the right side of the lower square patch resonator 9 determines the electric field strength of the third output port, thereby achieving the purpose of unequal power division. The isolation resistor 6 is directly above the upper square patch resonator 5 to ensure that the isolation between the second output port and the third output port is optimal.

[0031] The invention discloses a three-port filter power distributor based on a square patch resonator. In manufacturing, the metal surfaces on the front and back sides of a circuit substrate are processed and corroded by a printed circuit board manufacturing process to form a required metal pattern.

[0032] The present invention is further described in detail below with reference to the embodiments.

[0033] The dielectric substrates 1 and 3 used in the present invention have a relative dielectric constant of 3.55 and a thickness of 0.508 mm. Figure 4 and Figure 5 The size parameters of the power divider filter are as follows: a=20 mm, W1 = 1.4 mm, W2 = 0.8 mm, W3 =1.3 mm, h = 0.508 mm, l1 = 10mm, l2 = 6.8 mm, l3 =10mm, R=50Ω The three-port filter power divider in the present invention is modeled and simulated in the electromagnetic simulation software HFSS.15. Figure 6 The three-port filter power distributor of the present invention S Parameter simulation diagram. It can be seen from the figure that the passband center frequency of the four-way orthogonal signal generator is 3.8GHz and the relative bandwidth is 11%.

[0034] Figure 7 This is a simulation diagram of output port isolation of the three-port filter power divider in the present invention. It can be seen from the figure that the isolation of the three-port filter power divider in this example is better than -20dB.

[0035] In summary, the three-port filter power divider based on the square patch resonator of the present invention realizes a three-port filter power divider with filtering function and arbitrary power division ratio by feeding on patches with different electric field strengths, which is very suitable for modern communication systems.

[0036] It should be pointed out that the description of the above embodiments is only used to help understand the method of the present application and its core idea. For ordinary technicians in this technical field, several improvements and modifications can be made to the present application without departing from the principles of the present application. These improvements and modifications are also within the scope of protection of the claims of the present application.

Claims

1. A three-port filter power divider based on square patch resonator, characterized in that: It comprises a rectangular upper dielectric plate (2), a metal floor (1), and a rectangular lower dielectric plate (3) stacked in sequence from top to bottom, wherein a "cross" groove (11) is provided at the center of the metal floor (1); An input port feeder (4), an upper square patch resonator (5), and an isolation resistor (6) are provided on the upper surface of the upper dielectric plate (2); the upper square patch resonator (5) is located at the center of the upper dielectric plate (2); and the input port feeder (4) and the isolation resistor (6) are respectively vertically connected to different sides of the upper square patch resonator (5); A second output port feeder (7), a third output port feeder (8), and a lower square patch resonator (9) are provided on the lower surface of the lower dielectric plate (3); the lower square patch resonator (9) is located at the center of the lower dielectric plate (3); and the second output port feeder (7) and the third output port feeder (8) are respectively connected to different sides of the lower square patch resonator (9); The projection of the upper square patch resonator (5) on the lower surface of the lower dielectric plate (3) overlaps with the lower square patch resonator (9).

2. The three-port filter power divider based on square patch resonator according to claim 1, characterized in that: The input port feed line (4) is projected onto the lower surface of the lower dielectric plate (3) on the opposite side of the third output port feed line (8).

3. The three-port filter power divider based on square patch resonator according to claim 1, characterized in that: The isolation resistor (6) is projected onto the lower surface of the lower dielectric plate (3) on the same side as the second output port feeder (7).

4. The three-port filter power divider based on square patch resonator according to claim 1, characterized in that: The input port feed line (4) is located on the left side of the upper square patch resonator (5), one end of which is connected to the center of the left side of the upper square patch resonator (5), and the other end of which is connected to the center of the left side of the upper dielectric plate (2).

5. The three-port filter power divider based on square patch resonator according to claim 1, characterized in that: The isolation resistor (6) is located on the rear side of the upper square patch resonator (5), one end of which is connected to the center of the rear side of the upper square patch resonator (5) through a microstrip line (61), and the other end of which is connected to the metal floor (1) through a grounding column (62) that penetrates the upper dielectric plate (2).

6. The three-port filter power divider based on square patch resonator according to claim 1, characterized in that: The second output port feed line (7) is located on the rear side of the lower square patch resonator (9), one end of which is connected to the rear side edge of the lower square patch resonator (9), and the other end of which is vertically connected to the rear side edge of the lower dielectric plate (3).

7. The three-port filter power divider based on square patch resonator according to claim 1, characterized in that: The third output port feed line (8) is located on the right side of the lower square patch resonator (9), one end of which is connected to the right side edge of the lower square patch resonator (9), and the other end of which is vertically connected to the right side edge of the lower dielectric plate (3).

8. The three-port filter power divider based on square patch resonator according to claim 1, characterized in that: The input port feeder (4) comprises a connected input port 50 ohm microstrip line guide (42) and an input port quarter-wavelength transmission line (41); the second output port feeder (7) comprises a connected second output port 50 ohm microstrip line guide (72) and an output port quarter-wavelength transmission line (71); and the third output port feeder (8) comprises a connected third output port 50 ohm microstrip line guide (82) and an output port quarter-wavelength transmission line (81).

9. The three-port filter power divider based on square patch resonator according to claim 8, characterized in that: The input port 50 ohm microstrip line guide strip (42), the second output port 50 ohm microstrip line guide strip (72), and the third output port 50 ohm microstrip line guide strip (82) have the same size.

10. The three-port filter power divider based on square patch resonator according to claim 1, characterized in that: The upper dielectric plate (2) and the lower dielectric plate (3) have the same size.

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