Adjustable metamaterial composite structure based on microstrip line

Abstract

The invention discloses an adjustable metamaterial composite structure based on a microstrip line. The adjustable metamaterial composite structure comprises the microstrip line, a chip inductor, a variable capacitance diode, a magnetic bead and a resistor, the left side part and the right side part of the central conduction band of the microstrip line are respectively and periodically provided with mechanical through holes which are through up and down; the chip inductors are inserted into the mechanical through holes and are communicated with the central conduction band of the microstrip line and the grounding plate; the middle part of a central conduction band of the microstrip line is periodically engraved with double slits, the variable capacitance diodes cross each slit of the double slits and are communicated with the central conduction band of the microstrip line, the cathodes of the two variable capacitance diodes cross the double slits are opposite to each other, and a circuit for applying direct current voltage to the variable capacitance diodes is arranged between the cathodes of the two variable capacitance diodes; the middle part of the central conduction band of the microstrip line is arranged between the two slits and is also provided with a mechanical through hole penetrating up and down, and the magnetic bead is inserted into the mechanical through hole and is communicated with the central conduction band of the microstrip line and the grounding plate; the two tunneling peak frequencies of the adjustable metamaterial composite structure based on the microstrip line can be regulated and controlled through external voltage.

Description

A tunable metamaterial composite structure based on microstrip lines Technical Field

[0001] This invention relates to the field of metamaterials, and more particularly to a tunable metamaterial composite structure based on microstrip lines. Background Technology

[0002] By loading capacitors and inductors onto microstrip lines, metamaterials and metamaterial composite structures based on microstrip lines can be realized. These structures have attracted considerable interest due to their unique properties and important applications. The paper "Tuanhui Feng, Hongpei Han, Limin Wang, Fei Yang, Nonlinear metamaterial composite structure with tunable tunneling frequency [J], Progress In Electromagnetics Research Letters, 2017, 71: 91-96" proposes a metamaterial composite structure based on microstrip lines with a tunable tunneling frequency; however, this structure has only one tunneling peak. Some applications require two tunneling peaks, and the frequencies of these peaks must be tunable. Therefore, the existing technology, namely the metamaterial composite structure based on microstrip lines proposed in the literature "Tuanhui Feng, Hongpei Han, Limin Wang, Fei Yang, Nonlinear metamaterial composite structure with tunable tunneling frequency [J], Progress In Electromagnetics Research Letters, 2017, 71: 91-96.", has defects (only one tunneling peak) and needs to be improved. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a metamaterial composite structure based on microstrip lines with two tunneling peaks and the tunneling peak frequency can be tuned.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: a microstrip line-based tunable metamaterial composite structure, comprising a microstrip line, a surface-mount inductor, a varactor diode, a ferrite bead, and a resistor; the central conductor of the microstrip line is divided into three parts along its length: a left side part, a right side part, and a middle part; the left and right sides of the central conductor of the microstrip line are periodically provided with vertically penetrating mechanical through-holes, the surface-mount inductor is inserted into the mechanical through-holes, its upper end is connected to the central conductor of the microstrip line via solder, and its lower end is connected to the ground of the microstrip line via solder. The board is connected; the middle part of the central conductor of the microstrip line is periodically engraved with double slits, and the varactor diodes cross each of the double slits, with the left and right ends connected to the central conductor of the microstrip line through solder; a circuit for applying DC voltage to the varactor diodes is provided between the two varactor diodes crossing the double slits; the middle part of the central conductor of the microstrip line is also provided with a through-hole that runs vertically between the two double slits, and the magnetic bead is inserted into the through-hole, with the upper end connected to the central conductor of the microstrip line through solder and the lower end connected to the ground plane of the microstrip line through solder.

[0005] Preferably, in the microstrip-based tunable metamaterial composite structure, the two varactor diode cathodes spanning the double slits are opposite each other.

[0006] Preferably, in the microstrip-based tunable metamaterial composite structure, the microstrip line is implemented using a double-sided printed circuit board.

[0007] Preferably, in the microstrip-based tunable metamaterial composite structure, the circuit for applying DC voltage to the varactor diode includes, in addition to the copper plating of the printed circuit board, the resistor and the ferrite bead, both of which are soldered into the circuit.

[0008] Compared with the prior art, the beneficial effect is that, by adopting the above scheme, the metamaterial composite structure based on microstrip lines proposed in this invention has two tunneling peaks, and the frequency of the tunneling peaks can be tuned, thereby overcoming the defect of the prior art having only one tunneling peak. Attached Figure Description

[0009] Figure 1 is a schematic diagram of an embodiment of the present invention; Figure 2 shows the transmission characteristic curves of the tunable metamaterial composite structure based on microstrip lines proposed in the present invention under different voltages. Detailed Implementation

[0010] To facilitate understanding of the present invention, a more detailed description is provided below with reference to the accompanying drawings and specific embodiments. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0011] It should be noted that when a component is described as being "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is described as being "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "through," "left," "right," and similar expressions used in this specification are for illustrative purposes only.

[0012] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention.

[0013] This tunable metamaterial composite structure based on microstrip lines includes a microstrip line, a surface-mount inductor, a varactor diode, a ferrite bead, and a resistor. The central conductor of the microstrip line is divided into three parts along its length: a left side, a right side, and a middle section. The left and right sides of the central conductor of the microstrip line each have periodically perforated mechanical vias running vertically through them. The surface-mount inductor is inserted into these mechanical vias, with its upper end connected to the central conductor of the microstrip line via solder, and its lower end connected to the ground plane of the microstrip line via solder. The central conductor of the microstrip line... The middle section of the conductor strip is periodically engraved with double slits. The varactor diodes cross each of the double slits, and their left and right ends are connected by solder and the central conductor strip of the microstrip line. A circuit for applying DC voltage to the varactor diodes is provided between the two varactor diodes that cross the double slits. The middle section of the central conductor strip of the microstrip line is located between the two double slits and has a through-hole that runs vertically through it. The magnetic bead is inserted into the through-hole, with its upper end connected by solder and the central conductor strip of the microstrip line, and its lower end connected by solder and the ground plane of the microstrip line.

[0014] Preferably, in the microstrip-based tunable metamaterial composite structure, the two varactor diodes spanning the double slits have their cathodes facing each other. The microstrip line is implemented using a double-sided printed circuit board. The circuit for applying DC voltage to the varactor diodes includes, in addition to the copper plating of the printed circuit board, the resistors and ferrite beads, all of which are soldered into the circuit.

[0015] One embodiment of the present invention is shown in Figure 1. The tunable metamaterial composite structure based on a microstrip line includes a microstrip line 1, a surface-mount inductor 2, a varactor diode 3, a ferrite bead 4, and a resistor 5. Mechanical through-holes 7 are periodically formed on the left and right sides of the central conductor 6 of the microstrip line. The surface-mount inductor 2 is inserted into these mechanical through-holes, with its upper end connected to the central conductor of the microstrip line via solder, and its lower end connected to the ground plane of the microstrip line via solder. Each surface-mount inductor and its assigned microstrip line constitute a unit with a unit length of 4 mm. Double slits 8 are periodically etched in the middle of the central conductor 6 of the microstrip line. The varactor diode 3 spans each slit of the double slits 8, with its left and right ends connected to the central conductor of the microstrip line via solder. Two varactor diodes and their assigned microstrip lines constitute a unit with a unit length of 8 mm. mm; a circuit for applying DC voltage to the varactor diodes is provided between the two varactor diodes 3 that cross the double slits 8; the middle part of the central conductor 6 of the microstrip line is located between the two double slits 8, and a mechanical through hole 7 is also provided through the top and bottom. The magnetic bead 4 is inserted into the mechanical through hole, and its upper end is connected to the central conductor of the microstrip line through solder, and its lower end is connected to the ground plane of the microstrip line through solder.

[0016] Furthermore, the cathodes of the two varactor diodes 3 spanning the double slits 8 are opposite each other. The microstrip line 1 is implemented using a double-sided printed circuit board. The circuit for applying DC voltage to the varactor diodes 3, in addition to the copper plating of the printed circuit board, also includes the ferrite bead 4 and the resistor 5, both of which are soldered into the circuit.

[0017] According to the technical solution proposed in this invention, we fabricated a sample. The sample was fabricated using a double-sided printed circuit board with a dielectric constant of 2.65 and a dielectric thickness of 1.0 mm. The center conductor width of the microstrip line was 2.74 mm. The applied surface mount inductor had a value of 1.5 nH, the applied varactor diode was an Infineon BBY52, and the resistor soldered in the circuit applying DC voltage to the varactor diode had a value of 4700Ω. When voltage is applied, the positive terminal of the DC power supply is connected to the square copper-clad sheet 9, and the negative terminal of the DC power supply is connected to the ground plane of the microstrip line.

[0018] Figure 2 shows the transmission characteristic curves of the microstrip-based tunable metamaterial composite structure shown in Figure 1 under different voltages. As can be seen from Figure 2, the microstrip-based metamaterial composite structure shown in Figure 1 has two tunneling peaks, and the frequency of the tunneling peaks can be adjusted by the applied voltage. As the applied voltage increases, the two tunneling peaks of the metamaterial composite structure continuously shift to higher frequencies.

[0019] It should be noted that the above-mentioned technical features can be combined with each other to form various embodiments not listed above, all of which are considered to be within the scope of the present invention specification; and, for those skilled in the art, improvements or modifications can be made based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims of the present invention.

Claims

1. A tunable metamaterial composite structure based on microstrip lines, characterized in that... The system includes a microstrip line, a surface-mount inductor, a varactor diode, a ferrite bead, and a resistor. The central conductor of the microstrip line is divided into three parts along its length: a left side, a right side, and a middle section. The left and right sides of the central conductor of the microstrip line each have periodically perforated mechanical vias running vertically through them. The surface-mount inductor is inserted into these mechanical vias, with its upper end connected to the central conductor of the microstrip line via solder, and its lower end connected to the ground plane of the microstrip line via solder. The middle section of the central conductor of the microstrip line periodically... The device is etched with double slits, and the varactor diode spans each of the double slits. The left and right ends are connected by solder and the central conductor of the microstrip line. A circuit for applying DC voltage to the varactor diode is provided between the two varactor diodes spanning the double slits. The central conductor of the microstrip line is located between the two double slits and has a through-hole that runs vertically through it. The magnetic bead is inserted into the through-hole, with its upper end connected by solder and the central conductor of the microstrip line, and its lower end connected by solder and the ground plane of the microstrip line.

2. The tunable metamaterial composite structure based on microstrip lines according to claim 1, characterized in that... The two varactor diodes that span the double slits have their cathodes facing each other.

3. The tunable metamaterial composite structure based on microstrip lines according to claim 1, characterized in that... The microstrip line is implemented using a double-sided printed circuit board.

4. The tunable metamaterial composite structure based on microstrip lines according to claim 1, characterized in that... The circuit for applying DC voltage to the varactor diode includes, in addition to the copper plating of the printed circuit board, the resistor and the ferrite bead, both of which are soldered into the circuit.

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