Low-loss reconfigurable plasmonic transmission line

Abstract

The application provides a low-loss reconfigurable artificial surface plasmon transmission line, which comprises a dielectric substrate and a metal structure thereon. The metal structure is composed of periodically arranged first metal units; the first metal unit comprises a rectangular metal with a certain width, a zigzag metal and two varactor diodes, the rectangular metal is vertically placed with the zigzag metal, and the varactor diodes are connected in parallel to the two metal parts; the zigzag metal structure is in a corrugated shape, and the protruding part is a triangle. The low-loss reconfigurable artificial surface plasmon transmission line provided by the application can realize obvious loss reduction, realize continuous amplitude modulation of-1 dB to-40 dB in the Ku band, realize continuous phase modulation of more than 160° in the X band, and is expected to be applied to radio frequency microwave circuits.

Description

Technical Field

[0001] This invention belongs to the field of novel artificial electromagnetic materials technology, specifically relating to a low-loss reconfigurable artificial surface plasmon transmission line. Background Technology

[0002] Artificial surface plasmons are an electromagnetic mode that simulates the excellent characteristics of surface plasmons in the optical frequency band in the microwave band. They have the advantages of field confinement, field enhancement and flexible and controllable dispersion, and are widely used in microwave devices and systems such as filters, couplers, amplifiers, frequency multipliers and communication systems.

[0003] By introducing tunable components such as PIN diodes and varactor diodes into artificial surface plasmon transmission lines (ASPs), reconfigurable ASPs can be constructed. By adjusting the capacitance of the varactor diodes, the reconfigurable ASPs can manipulate subwavelength electromagnetic fields, i.e., manipulate the amplitude and phase of electromagnetic waves. This enables reconfigurable devices, circuits, and systems, greatly expanding the application of ASPs in various devices and systems.

[0004] However, traditional artificial surface plasmon unit patches are usually regular patterns such as rectangles, and their dispersion characteristics can only be controlled by structural parameters such as length and width, which limits the design freedom of the units. Summary of the Invention

[0005] The purpose of this invention is to solve the problem that traditional artificial surface plasmon unit patches are usually rectangular or other regular patterns, and the dispersion characteristics can only be controlled by structural parameters such as length and width, which limits the design freedom of the unit. By adopting a zigzag metal pleated structure, the depth and width of the pleats are increased as two controllable dimensions, which improves the design freedom of the unit and enhances its controllability, thus providing a low-loss reconfigurable artificial surface plasmon transmission line.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a low-loss reconfigurable artificial surface plasmon transmission line, comprising: a dielectric substrate and a metal structure thereon, wherein the metal structure comprises periodically arranged metal units;

[0007] The metal unit includes a rectangular metal, a zigzag metal, and two varactor diodes. The rectangular metal is perpendicular to the zigzag metal and is disposed on a dielectric substrate. The rectangular metal is connected to the zigzag metal through the varactor diodes. The zigzag metal is pleated, and the protruding part of the zigzag metal is triangular. In the metal unit, the dispersion characteristics of the transmission line are controlled by adjusting the pleat depth and width of the zigzag metal.

[0008] Furthermore, the rectangular metal is connected to the I-shaped metal via two parallel varactor diodes.

[0009] Furthermore, in the Ku band, the transmission line performs continuous amplitude modulation from -1dB to -40dB by adjusting the capacitance value of the varactor diode, and in the X band, the transmission line performs continuous phase modulation of more than 160° by adjusting the capacitance value of the varactor diode.

[0010] Furthermore, the rectangular metal units that are periodically arranged and interconnected are integrally formed. Beneficial effects

[0011] The present invention employs a zigzag metal with a pleated shape and a triangular protrusion, which enables the low-loss reconfigurable artificial surface plasmon transport line to have stronger field confinement and higher degree of controllability. Furthermore, its dispersion characteristics can be controlled by adjusting the depth and width of the zigzag metal pleats.

[0012] The low-loss reconfigurable artificial surface plasmon transmission line designed in this invention uses two parallel varactor diodes on the same metal unit, which can effectively reduce transmission loss and expand the range of variation of total capacitance value.

[0013] Based on the low-loss reconfigurable artificial surface plasmon transmission line designed in this invention, by changing the capacitance value of the varactor diode in the low-loss reconfigurable artificial surface plasmon transmission line, continuous amplitude modulation from -1dB to -40dB can be achieved in the Ku band, and continuous phase modulation of more than 160° can be achieved in the X band.

[0014] The low-loss reconfigurable artificial surface plasmon transmission line designed in this invention has a dispersion curve that can be controlled in real time by changing the capacitance value of the varactor diode. Attached Figure Description

[0015] Figure 1 The diagram shows the structure of the second metal unit in Embodiment 1 of the present invention (a) and its equivalent circuit diagram (b).

[0016] Figure 2 This is a dispersion curve diagram of the second metal unit under different widths of the zigzag metal folds in Embodiment 1 of the present invention.

[0017] Figure 3 This is a dispersion curve diagram of the second metal unit at different depths of the zigzag metal folds in Embodiment 1 of the present invention.

[0018] Figure 4 This is a dispersion curve diagram of the second metal unit under different capacitance values ​​of the varactor diode in Embodiment 1 of the present invention.

[0019] Figure 5The diagram shows the structure of the first metal unit in Embodiment 2 (a), the equivalent circuit diagram of the unit (b), and the dispersion curve of the first metal unit under different capacitance values ​​of the varactor diode (c).

[0020] Figure 6 This is a schematic diagram of the low-loss reconfigurable artificial surface plasmon transmission line in this invention.

[0021] Figure 7 This is the transmission coefficient of the low-loss reconfigurable artificial surface plasmon transmission line in the X-Ku band when the capacitance value C' is changed. and reflection coefficient The curve (a) and the transmission phase curve (b) in the X-band when the capacitance value C' of the transmission line is changed.

[0022] Figure 8 This is a loss comparison diagram between the low-loss reconfigurable artificial surface plasmon transmission line of this invention and the traditional reconfigurable artificial surface plasmon transmission line with only one varactor diode on each unit.

[0023] In the figure: 1. Dielectric substrate, 2. Metal structure, 3. First metal unit, 4. Rectangular metal, 5. Zigzag metal, 6. Varactor diode, 7. Second metal unit. Detailed Implementation

[0024] The invention will now be further explained with reference to the accompanying drawings.

[0025] The present invention provides a low-loss reconfigurable artificial surface plasmon transmission line, comprising: a dielectric substrate 1 and a metal structure 2 thereon, the metal structure 2 comprising periodically arranged metal units.

[0026] The metal unit includes a rectangular metal 4, a zigzag metal 5, and two varactor diodes 6. The rectangular metal 4 is perpendicular to the zigzag metal 5 and is disposed on the dielectric substrate 1. The rectangular metal 4 is connected to the zigzag metal 5 through the varactor diodes 6. The zigzag metal 5 is pleated, and the protruding part of the zigzag metal 5 is triangular. In the metal unit, the dispersion characteristics of the transmission line are controlled by adjusting the pleat depth and width of the zigzag metal 5.

[0027] In Example 1, the metal unit is the second metal unit 7, and in Example 2, the metal unit is the first metal unit 3. Example

[0028] like Figure 1 As shown, the present invention provides a low-loss reconfigurable artificial surface plasmon transmission line, including a dielectric substrate 1 and a metal structure 2 thereon, the metal structure 2 including periodically arranged second metal units 7.

[0029] The second metal unit 7 includes a rectangular metal 4, a zigzag metal 5, and a varactor diode 6. The rectangular metal 4 is perpendicular to the zigzag metal 5 and both are disposed on the dielectric substrate 1. The rectangular metal 4 is connected to the zigzag metal 5 through a varactor diode 6.

[0030] The zigzag metal 5 is wrinkled, and the protruding part of the zigzag metal 5 is triangular. In the metal unit, the dispersion characteristics of the transmission line are controlled by adjusting the wrinkle depth and width of the zigzag metal 5.

[0031] The rectangular metal 4s that are interconnected in the first metal unit 3, which are arranged periodically, are integrally formed.

[0032] In this embodiment, the second metal unit 7 is processed using mature PCB processing technology.

[0033] like Figure 2-3 As shown, the dispersion characteristics of the second metal unit 7 can be controlled by adjusting the width (d=0.5mm, 0.75mm, 1mm, 1.25mm) and depth (h=0.6mm, 1mm, 1.4mm, 1.8mm) of the zigzag metal 5 in the second metal unit 7.

[0034] like Figure 4 As shown, the dispersion characteristics of the second metal unit 7 can be changed in real time by changing the capacitance value of the varactor diode 6 in the second metal unit 7 (C=0.5pF, 0.75pF, 1pF, 2pF).

[0035] Compared with traditional reconfigurable artificial surface plasmon transmission lines, this embodiment uses a zigzag metal 5. The zigzag metal is wrinkled, and the protruding part of the zigzag metal is triangular, which increases the two controllable dimensions of the depth and width of the wrinkles, improves the design freedom of the unit, and can control the dispersion characteristics of the transmission line in this embodiment by adjusting the depth and width of the zigzag metal wrinkles, thus enhancing its controllability and making the transmission line in this embodiment have stronger field confinement ability.

[0036] In existing technologies, reconfigurable artificial surface plasmon transmission lines (ASPLs) can be constructed by introducing tunable components such as PIN diodes and varactor diodes. However, the introduction of tunable components inevitably introduces a problem: the inherent parasitic resistance of the tunable components increases the losses of the reconfigurable ASPLs, especially at higher frequencies or when the capacitance of the varactor diode is large. This problem severely limits the further development of reconfigurable ASPLs; therefore, it is necessary to find ways to reduce the losses caused by tunable components.

[0037] To address the issue that the inherent parasitic resistance of adjustable components increases the loss of reconfigurable artificial surface plasmon transmission lines, and to avoid signal energy loss, signal attenuation, and increased noise caused by transmission line loss, thereby reducing the impact on system energy efficiency, signal quality, and signal reliability, this invention provides a low-loss reconfigurable artificial surface plasmon transmission line as described in Embodiment 2, with the specific structure shown in Embodiment 2. Example

[0038] like Figure 5 As shown, the present invention provides a low-loss reconfigurable artificial surface plasmon transmission line, a dielectric substrate 1 and a metal structure 2 thereon, the metal structure 2 including periodically arranged first metal units 3.

[0039] The first metal unit 3 includes a rectangular metal 4, a zigzag metal 5, and two varactor diodes 6. The rectangular metal 4 is perpendicular to the zigzag metal 5 and is disposed on the dielectric substrate 1. The rectangular metal 4 is connected to the zigzag metal 5 through two parallel varactor diodes 6. The zigzag metal 5 is pleated, and the protruding part of the zigzag metal 5 is triangular. In the first metal unit 3, the dispersion characteristics of the transmission line are controlled by adjusting the pleat depth and width of the zigzag metal 5.

[0040] The rectangular metal 4s that are interconnected in the first metal unit 3, which are arranged periodically, are integrally formed.

[0041] In this embodiment, the first metal unit 3 is processed using mature PCB processing technology.

[0042] like Figure 5-6 As shown, the dispersion characteristics of the first metal unit 3 can be changed in real time by changing the capacitance value of the varactor diode 6 in the first metal unit 3 (C=0.5pF, 0.75pF, 1pF, 2pF).

[0043] Compared to the second metal unit 7 in Embodiment 1, the first metal unit 3 uses two parallel varactor diodes 6 to connect the rectangular metal 4 and the zigzag metal 5. The equivalent characteristic impedance of the first metal unit 3 is... The equivalent characteristic impedance of the second metal unit 7 is , where by and In comparison, it is deduced that the imaginary part of the characteristic impedance of the first metal unit 3 is only half that of the imaginary part of the characteristic impedance of the second metal unit 7. That is, the transmission loss of the first metal unit 3 is half that of the second metal unit 7, thereby effectively reducing the transmission loss. Here, C is the capacitance value of the varactor diode 6. and These are the characteristic impedance and electrical length of metal strip 4, respectively; and These are the characteristic impedance and electrical length of open-circuit stub 5, respectively. The electrical length of metal unit 3. Here, j is the frequency, j is the imaginary part, and r is the resistance value of the varactor diode.

[0044] Meanwhile, since the first metal unit 3 is equipped with two parallel varactor diodes, compared to the single varactor diode in the second metal unit 7, the total capacitance value of the first metal unit 3 has a larger range of variation.

[0045] in, and The formula is based on Figure 1 and Figure 5 The equivalent circuit diagram is derived from it.

[0046] like Figure 7 As shown, in the low-loss reconfigurable artificial surface plasmon transmission line proposed in this invention, by changing the capacitance value of the varactor diode, continuous amplitude modulation from -1dB to -40dB can be achieved in the Ku band, and continuous phase modulation of more than 160° can be achieved in the X band.

[0047] like Figure 8 As shown, compared to traditional reconfigurable artificial surface plasmon transmission lines with only one varactor diode on each transmission unit, the transmission coefficient of the low-loss reconfigurable artificial surface plasmon transmission line proposed in this invention is significantly improved, that is, it effectively reduces transmission loss.

[0048] In all the above embodiments, the rectangular metal 4 has a certain width.

[0049] In this invention, a low-loss reconfigurable artificial surface plasmon transmission line is formed by interconnecting several periodically arranged metal units, and the rectangular metal 4 interconnected among the periodically arranged metal units is integrally formed. In this low-loss reconfigurable artificial surface plasmon transmission line, by changing the capacitance value of the varactor diode, continuous amplitude modulation from -1dB to 40dB can be achieved in the Ku band, and continuous phase modulation of more than 160° can be achieved in the X band. Compared with the traditional reconfigurable artificial surface plasmon transmission line with only one varactor diode on each transmission unit, the transmission coefficient is significantly improved, and the transmission loss is effectively reduced.

[0050] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A low-loss reconfigurable artificial surface plasmon transmission line, characterized in that, include: A dielectric substrate (1) and a metal structure (2) thereon, the metal structure (2) comprising periodically arranged metal units; The metal unit includes a rectangular metal (4), a zigzag metal (5), and two varactor diodes (6). The rectangular metal (4) is perpendicular to the zigzag metal (5) and both are disposed on the dielectric substrate (1). The rectangular metal (4) is connected to the zigzag metal (5) through the varactor diodes (6). The zigzag metal (5) is pleated, and the protruding part of the zigzag metal (5) is triangular. In the metal unit, the pleat depth and width of the zigzag metal (5) are adjusted to control the dispersion characteristics of the transmission line.

2. The low-loss reconfigurable artificial surface plasmon transmission line according to claim 1, characterized in that, The rectangular metal (4) is connected to the I-shaped metal (5) via two parallel varactor diodes (6).

3. The low-loss reconfigurable artificial surface plasmon transmission line according to claim 1, characterized in that, In the Ku band, the transmission line is continuously modulated from -1dB to -40dB by adjusting the capacitance value of the varactor diode (6). In the X band, the transmission line is continuously modulated from more than 160° by adjusting the capacitance value of the varactor diode (6).

4. The low-loss reconfigurable artificial surface plasmon transmission line according to claim 1, characterized in that, Rectangular metals (4) connected to each other in a periodically arranged metal unit are integrally formed.

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