Spinning multiplexing dynamic holographic imaging device

Abstract

The utility model discloses a spin multiplexing dynamic holographic imaging device, which relates to the technical field of microwave frequency band electromagnetic wave regulation and control and comprises a plurality of dynamic achiral elements, and each dynamic achiral element sequentially comprises an umbrella-shaped patch structure, an upper-layer medium, a metal reflection back plate, a middle-layer medium, a feeder line structure and a lower-layer medium from top to bottom. The umbrella-shaped patch structure comprises a first arc arm, a second arc arm and a middle shaft, and PIN diodes are symmetrically embedded into the first arc arm and the second arc arm relative to the middle shaft. According to the utility model, the working states of the PIN diodes on the first arc arm and the second arc arm are respectively regulated and controlled, so that independent regulation and control of left-handed and right-handed circular polarization co-polarization reflection amplitudes and phases under the incidence of orthogonal circular polarization waves are realized; and arranging the plurality of dynamic achiral elements according to the regulated amplitude and phase distribution to form a spin multiplexing dynamic holographic imaging device, and respectively generating two completely different holographic images which are designed in advance in the corresponding polarization channels.

Description

Technical Field

[0001] The utility model relates to the technical field of microwave frequency band electromagnetic wave regulation, in particular to a spin multiplexing dynamic holographic imaging device. Background Art

[0002] Holographic imaging, usually used to record and reproduce the information of the target object, has become a thermoelectric problem in the field of electromagnetic research; with the rapid development of computer science and optoelectronics, computational holography has developed accordingly; by regulating the phase information of electromagnetic waves, the image of the target object can be flexibly reconstructed and displayed; metasurface, as a two-dimensional metamaterial, is composed of subwavelength scatterer units arranged in a two-dimensional plane. It is a composite material formed by subwavelength-scale units in a certain macroscopic arrangement and exhibiting extraordinary physical properties that natural materials do not have. It has unparalleled freedom and flexibility in controlling electromagnetic properties such as the amplitude, phase and polarization of electromagnetic waves, and is also widely used in fields such as near-field printing and holographic imaging.

[0003] Most existing holographic techniques often use circularly polarized waves as carriers for phase recovery and target transmission. Passive metasurfaces usually have a variety of phase modulation mechanisms to customize phase distribution on demand. For example, the phase modulation of the metasurface can achieve phase response by changing the medium size, geometric position, medium thickness and relative position, and modulate different electromagnetic functions; especially for circularly polarized wave control, the passive metasurface relies on the anisotropic structure with efficient polarization conversion characteristics to rotate a specific angle to construct a geometric phase to achieve hologram reconstruction; however, the geometric phase has a spin-locking effect for the case of orthogonal circularly polarized wave incidence, and cannot eliminate the coupling crosstalk in different polarization channels. At the same time, the passive metasurface is passive and cannot adjust its own scattering characteristics according to changes in the electromagnetic environment. The scattering characteristics of the metasurface can be dynamically adjusted by loading active devices such as diodes, graphene, and liquid crystals.

[0004] However, most of them are based on anisotropic structures under linear polarization wave incidence to achieve independent control of the incident wavefront of orthogonal linear polarization waves, but it is difficult to achieve independent control of the incident wavefront of orthogonal circular polarization waves. Utility Model Content

[0005] The embodiment of the utility model provides a spin multiplexing dynamic holographic imaging device, which can solve the problem in the prior art that it is difficult to achieve independent regulation of the incident wavefront of orthogonal circularly polarized waves.

[0006] The embodiment of the utility model provides a spin multiplexing dynamic holographic imaging device, comprising a plurality of dynamic non-chiral elements arranged in an array, wherein the dynamic non-chiral elements comprise an umbrella-shaped patch structure, wherein the umbrella-shaped patch structure is arranged on the top surface of an upper medium, and a metal reflective back plate is arranged on the bottom surface of the upper medium;

[0007] The first arc arm and the second arc arm of the umbrella-shaped patch structure are symmetrically embedded with PIN diodes about the central axis; and metallized vias are respectively arranged on the first arc arm and the second arc arm, and on the top of the central axis, and the first arc arm, the second arc arm and the metallized vias on the central axis are respectively connected to high and low levels with adjustable voltage through feeders to change the switching state of the PIN diode.

[0008] Preferably, it also includes a middle layer medium, a lower layer medium and a feeder structure;

[0009] The middle-layer medium is arranged on the bottom surface of the metal reflective back plate, the lower-layer medium is arranged on the bottom surface of the middle-layer medium, and the feeder structure is arranged on the top surface and the bottom surface of the lower-layer medium respectively;

[0010] The feeder structure is connected to the first arc arm, the second arc arm and the feeder connected on the central axis.

[0011] Preferably, it further comprises an external controller, wherein the external controller is connected to the feeder structure.

[0012] Preferably, the umbrella-shaped patch structure, the metal reflective backplane and the feeder structure are all copper structures.

[0013] Preferably, the upper medium and the lower medium are made of F4B board, whose relative dielectric constant is 2.65 and loss tangent is 0.001. The thickness of the upper medium is 4 mm, and the thickness of the lower medium is 0.25.

[0014] Preferably, the middle layer medium is a Rogers RO4450F board, which has a relative dielectric constant of 3.52, a loss tangent of 0.003, and a thickness of 0.18 mm.

[0015] Preferably, when the PIN diode on the first arc arm is in an on and off state, that is, in an open circuit and a short circuit state, the amplitude of the left-hand circularly polarized and co-polarized reflected waves at 9-10.5 GHz is greater than 0.9, and the phase difference is 180°;

[0016] When the PIN diode on the second arc arm is in the on and off state, that is, in the open circuit and short circuit state, the amplitude and phase response of the left-hand circularly polarized co-polarized reflected wave do not change.

[0017] Preferably, when the PIN diode on the second arc arm is in an on and off state, that is, in an open circuit and a short circuit state, the amplitude of the right-hand circularly polarized and co-polarized reflected waves at 9-10.5 GHz is greater than 0.9, and the phase difference is 180°;

[0018] When the PIN diode on the first arc arm is in an on and off state, that is, in an open circuit and a short circuit state, the amplitude and phase response of the right-hand circularly polarized and co-polarized reflected waves do not change.

[0019] The present invention provides a spin multiplexing dynamic holographic imaging device, which has the following beneficial effects compared with the prior art:

[0020] The external controller provided in the utility model inputs adjustable voltage high and low levels to the metallized via holes on the first arc arm and the second arc arm respectively through the feeder on the feeder structure, and inputs adjustable voltage high and low levels to the metallized via holes on the central axis, so that the P region and the N region of the PIN diodes provided on the first arc arm and the second arc arm show high and low levels, and the PIN diodes are forward biased or reverse biased, so that the resistance of the PIN diodes provided on the first arc arm and the second arc arm changes with the different high and low levels applied, thereby realizing independent regulation of the amplitude and phase of left-handed and right-handed circularly polarized co-polarized reflections under the incidence of orthogonal circularly polarized waves; because the working state of the PIN diodes provided on the first arc arm and the second arc arm, that is, the regulation of the resistance of the PIN diodes, is regulated by the adjustable voltage high and low levels applied by the external controller, thus realizing independent regulation before the incidence of the orthogonal circularly polarized waves.

[0021] In addition, the present invention arranges multiple dynamic achiral elements according to the adjusted amplitude and phase distribution to form a spin-multiplexing dynamic holographic imaging device, and generates two completely different pre-designed holograms in the corresponding polarization channels. At the same time, because the working state of the PIN diode can be adjusted at any time, the independent crosstalk-free phase control in the left-handed and right-handed orthogonal channels can be used to construct a hologram distribution of any polarization state. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of the overall structure of a spin multiplexing dynamic holographic imaging device and an exploded diagram of a dynamic non-chiral element provided in an embodiment of the utility model;

[0023] Figure 2 An exploded view of the structure of a dynamic achiral element of a spin-multiplexing dynamic holographic imaging device provided by an embodiment of the utility model; wherein: (a) is the structure and parameters of the dynamic achiral element; (b) is the structure and parameters of the umbrella-shaped patch structure; (c) is the structure and parameters of the middle-layer medium; (d) is the structure and parameters of the feeder structure;

[0024] Figure 3A schematic diagram of the circularly polarized wave amplitude and phase response of the two arms of the dynamic non-chiral element diode of a spin-multiplexing dynamic holographic imaging device provided by the embodiment of the utility model under different working states; wherein: (a) is the co-polarized reflection amplitude of the PIN diodes at the two arms under the incidence of left-handed circularly polarized waves when they are in the four states of "on / on", "on / off", "off / on" and "off / off" respectively; (b) is the co-polarized reflection phase of the PIN diodes at the two arms under the incidence of left-handed circularly polarized waves when they are in the four states of "on / on", "on / off", "off / on" and "off / off" respectively; (c) is the co-polarized reflection amplitude of the PIN diodes at the two arms under the incidence of right-handed circularly polarized waves when they are in the four states of "on / on", "on / off", "off / on" and "off / off"; (d) is the co-polarized reflection phase of the PIN diodes at the two arms under the incidence of right-handed circularly polarized waves when they are in the four states of "on / on", "on / off", "off / on" and "off / off";

[0025] Figure 4 A target hologram and a corresponding phase distribution diagram of a spin-multiplexing dynamic holographic imaging device provided by an embodiment of the utility model; wherein: (a) is a target image under left-hand circular polarization incidence; (b) is a phase distribution of a hologram under left-hand circular polarization incidence; (c) is a target image under right-hand circular polarization incidence; (d) is a phase distribution of a hologram under right-hand circular polarization incidence;

[0026] Figure 5 The present invention provides a method for simulating and testing a target hologram of a spin-multiplexing dynamic holographic imaging device in accordance with an embodiment of the present invention; wherein: (a) is the simulation result under left-hand circular polarization incident; (b) is the test result under left-hand circular polarization incident; (c) is the simulation result under right-hand circular polarization incident; and (d) is the test result under right-hand circular polarization incident.

[0027] Wherein: 10, dynamic achiral element, 101, umbrella-shaped patch structure, 102, upper medium, 103, metal reflective backplane, 104, middle medium, 105, feeder structure, 106, lower medium, 1011, first arc arm, 1012, second arc arm, 1013, central axis, 2, external controller. DETAILED DESCRIPTION

[0028] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the utility model. However, the utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the utility model, so the utility model is not limited by the specific embodiments disclosed below.

[0029] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0030] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0031] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0033] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0034] See also Figure 1 The embodiment of the utility model provides a spin multiplexing dynamic holographic imaging device, comprising a plurality of dynamic non-chiral elements 10, and the plurality of dynamic non-chiral elements 10 are distributed in an array.

[0035] like Figures 1-2 As shown, the dynamic non-chiral element 10 includes an umbrella-shaped patch structure 101, an upper medium 102, a metal reflective backplane 103, a middle medium 104, a feeder structure 105, and a lower medium 106; the umbrella-shaped patch structure 101 is welded on the upper side of the upper medium, the metal reflective backplane 103 is welded on the lower side of the upper medium 102, the feeder structure 105 is respectively welded on the upper and lower sides of the lower medium 106, and the middle medium 104 is used as an adhesive layer to connect the upper medium 102 and the lower medium 104.

[0036] Among them, the umbrella-shaped patch structure 101 is respectively embedded with PIN diodes at symmetrical positions along the central axis, and metallized vias are respectively provided in the middle of the left and right arms and the top of the central axis of the umbrella-shaped patch structure 101. The metallized vias in the middle of the left and right arms of the umbrella-shaped patch structure 101 are connected to the high level through the feeder, and the metallized vias at the top of the central axis of the umbrella-shaped patch structure 101 are connected to the low level through the feeder.

[0037] The feeder structure 105 receives the voltage provided by the external controller 2 to adjust the working state of the PIN diode in real time.

[0038] Among them, an intrinsic layer, namely the I layer, is sandwiched between the P region and the N region of the PIN diode. When different direct currents are applied to the P region and the N region, the number of carriers in the intrinsic layer will change; the resistance of the PIN diode is determined by the DC bias. When it is forward biased, the impedance is small and a short circuit will occur. When it is reverse biased, the impedance is large and an open circuit will occur.

[0039] Among them, the umbrella-shaped patch structure 101 includes a first arc arm 1011, and the co-polarization reflection phase control under the incidence of left-handed circularly polarized wave is realized by switching the working state of the diode arranged on the first arc arm 1011, so as to form a hologram in the left-handed channel; it also includes a second arc arm 1012, and the co-polarization reflection phase control under the incidence of right-handed circularly polarized wave is realized by switching the working state of the diode arranged on the second arc arm 1012, so as to form a hologram in the right-handed channel; it also includes a central axis 1013, one end of which is respectively connected to the first arc arm 1011 and the second arc arm 1012.

[0040] The metal reflective back plate 103 is used to completely reflect the incident circularly polarized wave.

[0041] Among them, the umbrella-shaped patch structure 101, the metal reflective backplane 103 and the feeder structure 105 are all made of copper; the upper medium 102 and the lower medium 106 are made of F4B board, the relative dielectric constant of the F4B board is 2.65, the loss tangent is 0.001, and the thicknesses are 4 mm and 0.25 mm respectively; the middle medium 104 is made of Rogers RO4450F board, the relative dielectric constant of the Rogers RO4450F board is 3.52, the loss tangent is 0.003, and the thickness is 0.18 mm.

[0042] like Figure 3 (a) to (b) show the circularly polarized wave amplitude and phase response of the two arms of the dynamic achiral element 10 diode under different working conditions under the incidence of left-handed circularly polarized wave; it can be seen that when the diode at the first arc arm 1011 is in the on or off state, the amplitude of the left-handed circularly polarized co-polarized reflected wave at 9-10.5GHz is above 0.9 on average, and the phase difference is about 180°, achieving 1-bit phase control; at the same time, when the diode at the second arc arm 1012 is in the on or off state, it has no effect on the amplitude and phase response of the left-handed circularly polarized co-polarized reflected wave, indicating good polarization isolation characteristics.

[0043] like Figure 3 (c) to (d) show the amplitude and phase response of the circularly polarized wave at the two arms of the dynamic achiral element 10 diode under different working conditions when a right-handed circularly polarized wave is incident. It can be seen that when the diode at the second arc arm 1012 is in the on or off state, the amplitude of the right-handed circularly polarized co-polarized reflected wave at 9-10.5 GHz is above 0.9 on average, and the phase difference is about 180°, achieving 1-bit phase control. At the same time, when the diode at the first arc arm 1011 is in the on or off state, it has no effect on the amplitude and phase response of the right-handed circularly polarized co-polarized reflected wave, indicating good polarization isolation characteristics.

[0044] like Figure 4(a)~(d) show the target holograms and the corresponding phase distribution in the dual channels. The two images "C" and "D" are pre-stored in the left-handed and right-handed co-polarized reflection channels respectively, and the phase distribution at different pixel points is reasonably arranged according to the image distribution.

[0045] like Figure 5 (a) to (d) show the simulation and test results of the target hologram in the dual channels. By changing the control voltage of the controller on each dynamic non-chiral element 10, each pixel in the orthogonal circular polarization and co-polarization reflection channel can have a customized phase, thereby generating a pre-stored target image in a given circular polarization channel. By reasonably arranging the phase distribution on the metasurface, any holographic image in the dual circular polarization channel can be generated immediately.

[0046] The above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A spin multiplexing dynamic holographic imaging device, characterized in that: include: A plurality of dynamic achiral elements (10) arranged in an array, wherein the dynamic achiral elements (10) include an umbrella-shaped patch structure (101), wherein the umbrella-shaped patch structure (101) is arranged on the top surface of an upper medium (102), and a metal reflective back plate (103) is arranged on the bottom surface of the upper medium (102); The first arc arm (1011) and the second arc arm (1012) of the umbrella-shaped patch structure (101) are symmetrically embedded with PIN diodes about the central axis (1013); and metallized vias are respectively provided on the first arc arm (1011) and the second arc arm (1012), and the top of the central axis (1013); the metallized vias on the first arc arm (1011), the second arc arm (1012) and the central axis (1013) are respectively connected to voltage-adjustable high and low levels through feed lines to change the switching state of the PIN diode.

2. The spin multiplexing dynamic holographic imaging device according to claim 1, characterized in that: Also includes: A middle layer medium (104), a lower layer medium (106) and a feeder structure (105); The middle-layer medium (104) is arranged on the bottom surface of the metal reflective back plate (103), the lower-layer medium (106) is arranged on the bottom surface of the middle-layer medium (104), and the feeder structure (105) is respectively arranged on the top surface and the bottom surface of the lower-layer medium (106); The feeder structure (105) is connected to the first arc arm (1011), the second arc arm (1012) and the feeder connected on the central axis (1013).

3. The spin multiplexing dynamic holographic imaging device according to claim 2, characterized in that: It also includes an external controller (2), wherein the external controller (2) is connected to the feeder structure (105).

4. The spin multiplexing dynamic holographic imaging device according to claim 1, characterized in that: The umbrella-shaped patch structure (101), the metal reflective back plate (103) and the feeder structure (105) are all copper structures.

5. The spin multiplexing dynamic holographic imaging device according to claim 2, characterized in that: The upper dielectric layer (102) and the lower dielectric layer (106) are made of F4B board, whose relative dielectric constant is 2.65 and loss tangent is 0.

001. The thickness of the upper dielectric layer (102) is 4 mm, and the thickness of the lower dielectric layer (106) is 0.

25.

6. The spin multiplexing dynamic holographic imaging device according to claim 2, characterized in that: The middle layer medium (104) is a Rogers RO4450F plate, which has a relative dielectric constant of 3.52, a loss tangent of 0.003, and a thickness of 0.18 mm.

7. The spin multiplexing dynamic holographic imaging device according to claim 1, characterized in that: When the PIN diode on the first arc arm (1011) is in an on and off state, that is, in an open circuit and a short circuit state, the amplitude of the left-hand circularly polarized co-polarized reflected wave at 9-10.5 GHz is greater than 0.9, and the phase difference is 180°; When the PIN diode on the second arc arm (1012) is in an on and off state, that is, in an open circuit and a short circuit state, the amplitude and phase response of the left-hand circularly polarized and co-polarized reflected waves do not change.

8. The spin multiplexing dynamic holographic imaging device according to claim 1, characterized in that: When the PIN diode on the second arc arm (1012) is in an on and off state, that is, in an open circuit and a short circuit state, the amplitude of the right-hand circularly polarized co-polarized reflected wave at 9-10.5 GHz is greater than 0.9, and the phase difference is 180°; When the PIN diode on the first arc arm (1011) is in an on and off state, that is, in an open circuit and a short circuit state, the amplitude and phase response of the right-hand circularly polarized and co-polarized reflected waves do not change.

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