A controllable attenuator based on complementary split-ring resonator structure

Abstract

The application provides a controllable attenuator based on a complementary open resonant ring structure, which is composed of a cascaded active gain compensation amplifier and an open resonant low-pass filter. The open resonant low-pass filter comprises a microstrip low-pass filter, a complementary open resonant ring, a variable capacitor and a control circuit. The microstrip low-pass filter is composed of a middle dielectric layer and a first metal surface and a second metal surface located on both sides of the dielectric layer. The complementary open resonant ring is designed on the second metal surface. The variable capacitor is connected in parallel between the inner metal surface and the outer metal surface of the complementary open resonant ring. The capacitance of the variable capacitor is adjusted through the control circuit, so as to control the attenuation amplitude of the controllable attenuator based on the complementary open resonant ring structure. The controllable attenuator based on the complementary open resonant ring structure has a very small volume and can be integrated into a chip.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of attenuators, and particularly relates to a controllable attenuator based on a complementary open resonant ring structure. BACKGROUND

[0002] An attenuator device is one of basic circuits for realizing the function of microwave power regulation in a wireless communication system. The existing technology usually adopts a multi-stage cascade form to realize controllable attenuation of microwave power, but the structure is complex, the volume is large, and the power attenuation precision is limited, so a small-size and high-precision controllable attenuator needs to be invented to solve the problems existing in the existing controllable attenuator.

[0003] As a basic unit of a left-handed metamaterial, the open resonant ring and the complementary open resonant ring structure have a negative dielectric constant or a negative magnetic permeability at a specific frequency, thus showing unique electromagnetic characteristics, and are one of research hotspots in recent years and are used in the design of antennas and microwave devices in a large amount. Due to the strong scattering effect, the signal wavelength is greatly reduced at the specific frequency, so the open resonant ring and the complementary open resonant ring structure can be used to realize the miniaturization of microwave devices, which provides a possible solution for the miniaturization and low cost of the attenuator.

[0004] An effective solution has not been proposed for the technical problem of complex structure and large volume caused by the traditional attenuator device in the related art. SUMMARY

[0005] In order to reduce the complexity, cost and volume of the circuit as much as possible, the application provides a controllable attenuator based on a complementary open resonant ring structure.

[0006] The application provides a controllable attenuator based on a complementary open resonant ring structure, which comprises a cascade active gain compensation amplifier and an open resonant filter, the open resonant filter comprises a filter, a complementary open resonant ring and a variable capacitor, the variable capacitor is connected in parallel between the inner metal surface and the outer metal surface of the complementary open resonant ring, and the capacitance of the variable capacitor is adjusted to control the attenuation amplitude of the controllable attenuator based on the complementary open resonant ring structure.

[0007] Optionally, the filter is a microstrip low-pass filter, and the microstrip low-pass filter comprises an intermediate dielectric layer, a first metal surface and a second metal surface located on the upper and lower sides of the dielectric layer, and the complementary open resonant ring is arranged on the second metal surface.

[0008] Optionally, the complementary open resonant ring can be circular, square or rhombic.

[0009] Optionally, the open resonant filter further comprises a control circuit, the capacitance of the variable capacitor is adjusted through the control circuit, the resonant characteristics of the complementary open resonant ring are adjusted, and finally the control of the attenuation amplitude is realized.

[0010] Optionally, the variable capacitance is a reverse-biased diode or a MOS capacitor.

[0011] Optionally, the controllable attenuator, according to actual needs, determines whether to adopt an active gain compensation circuit, and if so, provides positive gain or negative gain according to actual needs.

[0012] The controllable attenuator based on the complementary open-loop resonant ring structure of the present application has a simple structure, and the size of the microstrip low-pass filter and the size of the complementary open-loop resonant ring can be less than one-tenth of the wavelength. With the increase of the working frequency, due to the decrease of the wavelength, the controllable attenuator based on the complementary open-loop resonant ring structure of the present application has a very small volume and cost. Especially in the millimeter wave or terahertz frequency band, the smaller wavelength makes the controllable attenuator based on the complementary open-loop resonant ring structure have a very small volume, which can realize chip integration.

[0013] The controllable attenuator based on the complementary open-loop resonant ring structure of the present application has a simple structure, and the size of the microstrip low-pass filter and the size of the complementary open-loop resonant ring can be less than one-tenth of the wavelength. With the increase of the working frequency, due to the decrease of the wavelength, the controllable attenuator based on the complementary open-loop resonant ring structure of the present application has a very small volume and cost. Especially in the millimeter wave or terahertz frequency band, the smaller wavelength makes the controllable attenuator based on the complementary open-loop resonant ring structure have a very small volume, which can realize chip integration. BRIEF DESCRIPTION OF DRAWINGS

[0014] The accompanying drawings, which are included to provide a further understanding of the present application and are incorporated in and constitute a part of this application, illustrate embodiments of the present application and together with the description serve to explain the present application. In the drawings:

[0015] Figure 1 is a schematic diagram of a controllable attenuator based on a complementary open-loop resonant ring structure according to an embodiment of the present application;

[0016] Figure 2 is two possible implementation examples of a complementary open-loop resonant ring according to the present application;

[0017] Figure 3 is a first possible example of a controllable attenuator based on a complementary open-loop resonant ring structure according to an embodiment of the present application;

[0018] Figure 4 is a second possible example of a controllable attenuator based on a complementary open-loop resonant ring structure according to an embodiment of the present application. DETAILED DESCRIPTION

[0019] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application. In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0020] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. Meanwhile, in the description of the present application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0021] The embodiment of the present application provides a controllable attenuator based on a complementary open resonant ring structure, Figure 1 The embodiment of the present application provides a schematic diagram of the controllable attenuator based on the complementary open resonant ring structure.

[0022] As shown in the figure, Figure 1 The controllable attenuator based on the complementary open resonant ring structure provided by the embodiment of the present application is composed of an active gain compensation amplifier 101 and an open resonant low-pass filter 102 in series. The active gain compensation circuit is determined according to actual needs, and if it is needed, positive gain or negative gain is provided according to actual needs. The composition of the open resonant low-pass filter 102 includes a microstrip low-pass filter 111, a complementary open resonant ring 112, a variable capacitor 113 and a control circuit.

[0023] In the embodiment of the present application, the form of the microstrip low-pass filter 111 is not unique, and possible implementation schemes include PCB or chip. As shown in the figure, Figure 1 The microstrip low-pass filter 111 is composed of an intermediate dielectric layer 121 and a first metal surface 122 and a second metal surface 123 located on both sides of the dielectric layer. The first metal surface 122 is the structure of the microstrip low-pass filter 111, and the second metal surface 123 is the bottom plate structure of the microstrip low-pass filter 111; the complementary open resonant ring 112 is designed on the second metal surface 123.

[0024] In the embodiment of the present application, the variable capacitor 113 is connected in parallel between the inner metal surface and the outer metal surface of the complementary open resonant ring 112, and the capacitance of the variable capacitor 113 is adjusted through the control circuit, so that the amplitude of the attenuator is controllable.

[0025] In the embodiment of the present application, the structure of the microstrip low-pass filter 111 is not unique, and the possible implementation structure is determined by actual circuit requirements; the structure of the complementary open resonant ring 112 is not unique, and possible implementation schemes include circular structure, square structure or other open resonant ring structure, such asFigure 2 as shown;

[0026] In the embodiment of the present application, the specific position and number of the complementary open-loop resonant ring 112 on the second metal surface 123 are not unique, and the possible position and number of the complementary open-loop resonant ring are determined by the structure of the microstrip low-pass filter 111 and the actual circuit requirement; the possible form of the variable capacitor 113 is not unique, and the possible implementation scheme includes a reverse-biased diode or a MOS capacitor.

[0027] In the embodiment of the present application, the opening direction angle of the complementary open-loop resonant ring 112 will affect the resonant characteristics of the whole structure, and then affect the attenuation amplitude and effect, so it is adjusted according to the specific shape.

[0028] In the embodiment of the present application, the controllable attenuator determines whether to adopt an active gain compensation circuit according to the actual requirement, and if it is adopted, the positive gain or negative gain is provided according to the actual requirement. The active gain compensation amplifier 101 is added at the input end or the output end of the open-loop resonant low-pass filter 102.

[0029] Therefore, the controllable attenuator based on the complementary open-loop resonant ring structure has multiple possible implementation schemes, and the present application only gives two possible implementation schemes as examples Figure 3 and Figure 4 , but the actual implementation is not limited to the two possible implementation schemes.

[0030] Embodiment 1

[0031] The first possible implementation scheme of the controllable attenuator based on the complementary open-loop resonant ring structure is as Figure 3 shown. The input end of the active amplifier of the controllable attenuator is connected to the external signal input end, the output end is connected to the input end of the open-loop resonant low-pass filter 102, and the output end of the open-loop resonant low-pass filter 102 is connected to the external load. The gain of the active amplifier is determined by the actual requirement of the circuit. The microstrip low-pass filter 111 is located on the first metal surface 122 above the middle dielectric plate, the complementary open-loop resonant ring 112 adopts a circular structure, the number is 2, and is located on the second metal surface 123 below the middle dielectric plate. The opening direction of the complementary open-loop resonant ring 112 is θ=45°.

[0032] The variable capacitor 113 is realized by a reverse-biased diode, and the number of the reverse-biased diode is selected to be 2. One end of the variable capacitor 113 is connected to the inner metal surface of the circular complementary open-loop resonant ring 112, and the other end is connected to the outer metal surface of the circular complementary open-loop resonant ring 112. By adjusting the bias voltage of the reverse-biased diode, the capacitance of the reverse-biased diode is controllable, and then the resonant characteristics of the circular complementary open-loop resonant ring 112 are changed, so as to control the attenuation amplitude of the controllable attenuator based on the complementary open-loop resonant ring structure.

[0033] Example 2

[0034] A possible implementation scheme for a controllable attenuator based on a complementary open-loop resonant ring structure is as follows: Figure 4 As shown. This controllable attenuator does not use an active amplifier. The input terminal of the split-ring resonant low-pass filter 102 is connected to an external signal input terminal, and the output terminal of the split-ring resonant low-pass filter 102 is connected to an external load. The microstrip low-pass filter 111 is located on the first metal surface 122 above the intermediate dielectric substrate. The complementary split-ring resonators 112 have a square structure, and there are four of them, located on the second metal surface 123 below the intermediate dielectric substrate. The opening direction of the complementary split-ring resonators 112 is θ = 0°.

[0035] The variable capacitor 113 is implemented using MOS capacitors, with four MOS capacitors selected. One end of each MOS capacitor is connected to the inner metal surface of the square complementary open-circuit resonator 112, and the other end is connected to the outer metal surface of the square complementary open-circuit resonator 112. By adjusting the bias voltage of the MOS capacitors, the capacitance value can be controlled, thereby changing the resonance characteristics of the square complementary open-circuit resonator 112 and achieving control over the attenuation amplitude of the controllable attenuator based on the complementary open-circuit resonator structure.

[0036] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A controllable attenuator based on a complementary split ring resonator structure, characterized by, The application relates to a controllable attenuator, which comprises the following parts: a cascade active gain compensation amplifier and an open resonant filter, wherein the open resonant filter comprises a filter, a complementary open resonant ring and a variable capacitor; the complementary open resonant ring is added on the filter; the variable capacitor is connected in parallel between the inner metal surface and the outer metal surface of the complementary open resonant ring; and the attenuation amplitude of the controllable attenuator based on the complementary open resonant ring structure is controlled by adjusting the capacitance of the variable capacitor. The filter is a microstrip low-pass filter, which comprises an intermediate dielectric layer, a first metal surface and a second metal surface arranged on the upper and lower sides of the dielectric layer, and a complementary open resonant ring arranged on the second metal surface. The open resonant filter further comprises a control circuit, which is used for adjusting the capacitance of the variable capacitor, adjusting the resonant characteristics of the complementary open resonant ring, and finally controlling the attenuation amplitude.

2. The controllable attenuator of claim 1, wherein, The complementary open resonant ring can be circular, square or diamond-shaped.

3. The controllable attenuator of claim 1, wherein, The variable capacitor is a reverse-biased diode or a MOS capacitor.

4. Controllable attenuator according to any one of claims 1 to 3, characterized in that The controllable attenuator can or can not adopt an active gain compensation circuit according to actual requirements, and if the active gain compensation circuit is adopted, positive gain or negative gain is provided according to actual requirements.

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