Gain millimeter wave programmable metasurface regulated and controlled by MOS switch

Abstract

The invention discloses a gain millimeter wave programmable metasurface regulated and controlled by an MOS switch, and belongs to the field of novel artificial electromagnetic materials. According to the structure, a reflective metasurface unit integrating the power amplifier and the MOS switch chip is realized, x-polarized wave receiving is realized in the high-isolation dual-polarized rectangular patch antenna unit structure, y-polarized wave re-radiation is realized after micro-strip transmission and amplification, y-polarized reflection phase can be changed by adjusting on-off of the MOS switch chip, and the antenna has the advantages of high-isolation dual-polarized rectangular patch antenna unit structure, high-isolation dual-polarized rectangular patch antenna unit structure and high-isolation dual-polarized rectangular patch antenna unit structure. The metasurface array has a very good 1bit effect while ensuring active amplification of signals, so that coding state switching of the metasurface units and far-field beam regulation and control of the metasurface array are realized. The surface is a millimeter wave artificial electromagnetic surface with an active amplification function, is expected to solve the problems of path loss and reflection loss of a current reflective metasurface and the problem of radio frequency signal leakage caused by a programmable metasurface bias circuit, and has important potential application in the fields of intelligent communication, imaging, computing technology and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of novel artificial electromagnetic materials, and in particular to a gain millimeter-wave programmable metasurface controlled by a MOS switch. Background Art

[0002] Metamaterials are artificial materials that achieve flexible control of electromagnetic waves through the periodic or aperiodic arrangement of subwavelength-scale structural units. Artificial electromagnetic surfaces (metasurfaces) are two-dimensional structures developed from new three-dimensional artificial electromagnetic materials (metamaterials). For this two-dimensional artificial electromagnetic surface, its units can be independently designed, so that each unit can independently control the amplitude and phase of the electromagnetic wave, thereby obtaining more complex field distribution results. Based on this phase or amplitude discontinuity, the units can be discretized into a finite number of types and described by digital codes, also known as digitally coded metamaterials. For example, if the reflection phases of two units differ by 180° but the amplitudes are similar, two codes, "0" and "1", can be obtained. With the continuous advancement of technology, digitally coded metamaterials can also be expanded to 2-bit and even multi-bit codes, further enhancing the diversity and richness of their applications.

[0003] Existing PIN diode-based control solutions have significant technical limitations. They must introduce a bias circuit network into the RF link, which significantly increases RF signal leakage. Furthermore, the path loss and reflection loss issues of current high-frequency reflective metasurfaces limit their signal coverage and communication applications. Summary of the Invention

[0004] The present invention provides a millimeter-wave programmable metasurface with gain controlled by MOS switches, which is a millimeter-wave artificial electromagnetic surface with active amplification function. It is expected to solve the path loss and reflection loss problems existing in current reflective metasurfaces, as well as the radio frequency signal leakage problem caused by programmable metasurface bias circuits. It has important potential applications in the fields of intelligent communications, imaging, and computing technology.

[0005] An embodiment of the present invention provides a gain millimeter-wave programmable metasurface controlled by a MOS switch. The metasurface is composed of a two-dimensional array consisting of a plurality of subwavelength units. Each subwavelength unit includes a radiation patch (1), a microstrip radio frequency link (2), a substrate (3), a power amplifier chip (7), a MOS switch chip (8), and a slotted metal backplane (4).

[0006] The radiation patch (1) is arranged on the top layer of the sub-wavelength unit and is etched on the substrate;

[0007] The microstrip radio frequency link (2) is arranged at the bottom layer of the subwavelength unit and is located on the back side of the substrate;

[0008] The substrate (3) is a multi-layer dielectric structure, with a metal structure layer (6) between each dielectric layer;

[0009] A slotted metal backplane (4) is etched on a metal structure layer between a bottom layer and a sub-bottom layer medium, and is separated from a microstrip radio frequency link by a layer of medium; three hourglass-shaped radiation slots (5) are provided on the metal backplane, wherein the vertically opened radiation slot is located at the center of the backplane and is arranged orthogonally to the other two horizontally opened hourglass-shaped radiation slots;

[0010] The power amplifier chip (7) and two MOS switch chips (8) are attached to the back of the substrate and bonded to the microstrip radio frequency link by gold wires.

[0011] Optionally, in one embodiment of the present invention, the radiation patch is a rectangular structure, the material is copper, and the operating frequency is a millimeter wave band.

[0012] Optionally, in one embodiment of the present invention, the substrate is a five-layer dielectric structure of Rogers RO4350B and Rogers RO4450F overlapped, the top layer is Rogers RO4450F, the dielectric constants are 3.66 and 3.7, and the loss tangents are 0.0037 and 0.004 respectively.

[0013] Optionally, in one embodiment of the present invention, the material used for the underlying microstrip RF link and the slotted metal backplane is copper. The slotted metal backplane adopts an hourglass-shaped groove to ensure that the electromagnetic energy is efficiently coupled to the underlying microstrip transmission link, and then amplified by the power amplifier and then selected by the MOS switch. The two channels lead to two hourglass-shaped radiation slots orthogonal to the central slot respectively. The two radiation slots achieve a 180° phase difference while implementing secondary radiation through an inverted feeding design.

[0014] Optionally, in one embodiment of the present invention, different coding arrangements are calculated according to different functional requirements, and a field programmable gate array (FPGA) is used to program and control the distribution of the bias voltage and reconstruct the reflection phase distribution.

[0015] The gain millimeter-wave programmable metasurface controlled by MOS switches in the embodiment of the present invention has the following beneficial effects:

[0016] 1. The present invention provides a gain-programmable millimeter-wave metasurface based on MOS switch regulation. Compared with the existing coding metasurface, it has the characteristics of active amplification reflection, electrically programmable, and reconfigurable.

[0017] 2. The present invention adopts the electromagnetic characteristics of the self-developed MOS switch chip control unit, which has the advantages of radio frequency isolation and good stability compared to the PIN diode control method.

[0018] 3. The present invention expands the operating frequency of the programmable metasurface to the millimeter wave frequency region by designing a gain-programmable metasurface unit based on MOS switch control, thereby greatly expanding the control capability of millimeter waves.

[0019] 4. The method proposed in the present invention is to realize x-polarized wave reception by designing a high-isolation dual-polarized rectangular patch in the metasurface unit, and re-radiate it as y-polarized wave after microstrip transmission and power amplifier amplification, and control the y-polarized radiation phase by adjusting the on-off of the MOS switch chip. It can ensure active signal amplification while achieving an excellent 1-bit effect. It is an active amplifying and reflecting unit in the millimeter wave frequency band, which is highly innovative and feasible.

[0020] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0022] Figure 1 A schematic diagram of a three-dimensional structure of a gain millimeter-wave programmable metasurface unit controlled by a MOS switch according to an embodiment of the present invention;

[0023] Figure 2 A schematic diagram of a millimeter-wave programmable metasurface structure with gain controlled by a MOS switch according to an embodiment of the present invention;

[0024] Figure 3 (a) is a schematic diagram of the top structure of the unit. The unit is a square with a side length of p. The width of the rectangular radiation patch is p1;

[0025] Figure 3 (b) is a schematic diagram of the unit's underlying structure, hiding the dielectric layer between the slotted metal backplane and the microstrip line. The microstrip line lengths are l1, l2, l3, and l4, respectively, and the microstrip width is w. Space is reserved between the four microstrip sections as ports for the MOS switch chip and amplifier chip, and the chip and microstrip are bonded via gold wire. The dimensions of the horizontal hourglass slot and the vertical hourglass slot are a1, a2, b1, and b2, and a3, a4, b3, and b4, respectively.

[0026] Figure 3(c) is a schematic diagram of the unit substrate layer structure. The substrate is a five-layer dielectric structure consisting of RO4350B substrate and Rogers RO4450F PP layer. The top layer is Rogers RO4450F. There are metal layers between each layer as control line and power line routing layers. The thickness of the center layer is h2, and the thickness of the other layers is h1. The slotted metal backplane is located between the bottom layer and the fourth layer.

[0027] Figure 4 1 is a curve showing a change in reflection amplitude caused by two reflection states when an active power amplifier is not integrated in an embodiment of the present invention;

[0028] Figure 5 1 is a reflection phase change curve caused by two reflection states when the active power amplifier is not integrated in the embodiment of the present invention;

[0029] Figure 6 This is a reflection amplitude variation curve caused by two reflection states when an active power amplifier is integrated in an embodiment of the present invention;

[0030] Figure 7 This is a reflection phase change curve caused by two reflection states when an active power amplifier is integrated in an embodiment of the present invention;

[0031] Figure 8 The three-dimensional far-field scattering pattern of the metasurface with the coding sequence of 0110011001 according to an embodiment of the present invention, where the operating frequency is 30 GHz and the angle between the beam and the z-axis is 30°;

[0032] Figure 9 This is the three-dimensional far-field scattering pattern of the metasurface with a coding sequence of 0111000111 according to an embodiment of the present invention, where the operating frequency is 30 GHz and the angle between the beam and the z-axis is 20°. DETAILED DESCRIPTION

[0033] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0034] like Figure 1 and Figure 2 As shown, the MOS switch-controlled gain millimeter-wave programmable metasurface is composed of a two-dimensional array of multiple subwavelength units, each of which includes a radiation patch (1), a microstrip radio frequency link (2), a substrate (3), a power amplifier chip (7), a MOS switch chip (8) and a slotted metal backplane (4);

[0035] The radiation patch (1) is arranged on the top layer of the sub-wavelength unit and is etched on the substrate;

[0036] The microstrip radio frequency link (2) is arranged at the bottom layer of the subwavelength unit and is located on the back side of the substrate;

[0037] The substrate (3) is a multi-layer dielectric structure, with a metal structure layer (6) between each dielectric layer;

[0038] A slotted metal backplane (4) is etched on a metal structure layer between a bottom layer and a sub-bottom layer medium, and is separated from a microstrip radio frequency link by a layer of medium; three hourglass-shaped radiation slots (5) are provided on the metal backplane, wherein the vertically opened radiation slot is located at the center of the backplane and is arranged orthogonally to the other two horizontally opened hourglass-shaped radiation slots;

[0039] The power amplifier chip (7) and two MOS switch chips (8) are attached to the back of the substrate and bonded to the microstrip radio frequency link by gold wires.

[0040] In one embodiment of the present invention, the radiating patch is a rectangular structure made of copper, operates in the millimeter-wave band, and is etched onto a multilayer substrate. The slotted metal backplane is made of copper, which effectively suppresses the transmission of millimeter-wave electromagnetic waves, making it a reflective metasurface. The slotted metal backplane utilizes hourglass-shaped slots to ensure efficient coupling of electromagnetic energy to the underlying microstrip transmission link. After amplification by a power amplifier, a MOS switch selects the channel. The two channels lead to two hourglass-shaped radiating slots orthogonal to the central slot. These two radiating slots utilize an anti-phase feed design to achieve a 180° phase difference while implementing secondary radiation.

[0041] The dielectric substrate is a five-layer structure of Rogers RO4350B and Rogers RO4450F overlapping each other. The top layer is Rogers RO4450F, with dielectric constants of 3.66 and 3.7, loss tangents of 0.0037 and 0.004, respectively. There are metal routing layers between each dielectric layer.

[0042] In one embodiment of the present invention, a MOS switch-controlled gain programmable metasurface solution is proposed. A self-developed three-port MOS switch is used as the core control element, and the on-off state is controlled by the gate voltage. Compared with the traditional PIN diode solution, there is no need to introduce additional bias circuits in the RF link, which effectively avoids the RF bias interference problem of the traditional PIN diode. Within the preset working frequency band, the MOS switch dynamically switches the RF transmission path, and the two hourglass-shaped radiation slots with reverse phase feeding realize the reconfigurable radiation with a reflection phase of 0° or 180°.

[0043] In one embodiment of the present invention, a power amplifier is integrated into the radio frequency link to effectively compensate for the energy loss of the traditional reflective metasurface, and an active amplification mechanism is introduced to achieve a paradigm shift from passive reflection to active amplification.

[0044] In one embodiment of the present invention, different coding arrangements can be calculated according to different functional requirements, and the FPGA provides independent control channels to drive the metasurface.

[0045] In one embodiment of the present invention, after receiving an incident electromagnetic wave, it is amplified by a power amplifier. Subsequently, by controlling the on / off states of a MOS switch, an actively amplified reflected wave is generated, with similar amplitudes but 180° difference in reflected phase. This unique phase control property enables the metasurface unit to achieve two basic coding states, "0" and "1," and electromagnetic control can be achieved through the rational design of the unit arrangement.

[0046] The metasurface unit of the embodiment of the present invention exhibits distinct reflection properties when the MOS switch is in different on-off states. This means that within a certain frequency range, electromagnetic waves can be reflected with similar amplitudes and a 180° phase difference, thereby achieving two coding states of "0" and "1" and enabling real-time switching. Furthermore, the unit successfully introduces an active amplification mechanism by integrating a power amplifier module into the RF link. This design effectively compensates for the metasurface's energy loss, enabling the metasurface to possess active signal amplification capabilities. This technology may be applied in the practical engineering of programmable metasurfaces.

[0047] The metasurface of the embodiment of the present invention can calculate different coding arrangements according to different functional requirements. The distribution of the bias voltage is programmed and controlled by FPGA, which can realize the reconfiguration of the reflection phase distribution, and further realize the flexible control of the millimeter wave beam to achieve various functions such as abnormal beam deflection and beam scanning. Therefore, it is a programmable electromagnetic metasurface.

[0048] like Figure 3As shown in (a), (b) and (c), the structure of the gain millimeter-wave programmable metasurface controlled by MOS switches is demonstrated. Its structure mainly consists of a radiation patch, a microstrip transmission line, a MOS switch, a power amplifier chip, a substrate and a slotted metal backplane. The top radiation patch of the present invention is a rectangular structure, its operating frequency is the millimeter-wave frequency band, the material used is copper, and the thickness is 18 microns. The dielectric substrate is a stacked structure including a Rogers RO4350B substrate and a Rogers RO4450F PP layer. From the top layer to the metal backplane, it is specifically divided into a 100um Rogers RO4450F PP layer, a 100um Rogers RO4350B substrate, a 200um Rogers RO4450F PP layer, and a 100um Rogers RO4350B substrate. There is a 35um metal layer between each layer, and the material is copper, which serves as the control line and power line routing layer. The slotted metal backplane and the final layer of microstrip RF link are separated by a 100um Rogers RO4450F layer. The microstrip is 18um thick and is used for RF transmission. The metal backplane is made of copper with a thickness of 35 microns, which can effectively suppress the transmission of millimeter-wave electromagnetic waves. Therefore, this is a reflective artificial electromagnetic surface.

[0049] The operating principle of this MOS switch-controlled gain-programmable millimeter-wave metasurface is as follows. When an x-polarized incident wave is perpendicular to the metasurface, the electromagnetic wave energy is coupled to a microstrip transmission line through the hourglass-shaped slot in the center of the metal backplane. After amplification by a power amplifier, channel selection is achieved by changing the on / off state of the MOS switch chips bonded to two different microstrip transmission lines. An hourglass-shaped radiation slot, orthogonal to the center slot, is selected for y-polarized secondary radiation. The radiation slots of the two channels are designed with anti-phase feeds to achieve reflected waves with similar amplitudes and a 180° phase difference. By selecting an appropriate operating frequency band, the reflected electromagnetic wave unit has similar amplitudes in both states, but a 180° phase difference. This results in two basic coding units, labeled "0" and "1." Arranging the different coding units in a specific sequence can create a metasurface with a specific function. Since the unit structure is identical, this greatly simplifies the array configuration process. Here, the present invention will integrate FPGA with metasurface array. For complex arrays with specific functional requirements, the coding sequence obtained by computational simulation can be stored in the FPGA, and the FPGA can be used to achieve rapid switching of the metasurface coding state, thereby obtaining the required far-field beam distribution.

[0050] Example 1: Figure 3The structural unit shown has a period of p = 5000um for the square unit and a width of p1 = 2650um for the rectangular radiation patch. The microstrip line lengths are l1 = 3450um, l2 = 1200um, l3 = 1800um, and l4 = 900um, and the microstrip width is w = 200um. 1400um and 920um are reserved between the four microstrip sections as interfaces for the MOS switch chip and the amplifier chip, respectively. The chip and the microstrip are bonded with gold wires. The dimensions of the horizontal hourglass slot and the vertical hourglass slot are a1 = 300um, a2 = 425um, b1 = 100um, b2 = 1000um and a3 = 300um, a4 = 425um, b3 = 100um, and b4 = 740um, respectively. The substrates are RO4350B and Rogers RO4450F. The dielectric structure consists of five overlapping PP layers, with a center layer thickness of h2 = 200 μm and the remaining layers of h1 = 100 μm. Between each layer, a 35 μm thick copper layer serves as the routing for control and power lines. The outermost microstrip and rectangular patch layers have a copper thickness of 18 μm. By switching the MOS switch chip on and off, the "0" and "1" states under different polarizations are achieved.

[0051] CST Microwave Studio was used to perform electromagnetic simulation on the above unit, and the S parameters when the amplifier is not loaded were obtained as follows: Figure 4 and Figure 5 As shown. Around 30GHz, the amplitude of the reflection coefficient S12 in the two states is basically equal, while the phase difference is 180°, which meets the requirements of the "0" state and "1" state in the aforementioned coding metasurface. Using CST to perform field-circuit joint simulation, when the amplifier circuit is loaded, the S parameters are as follows Figure 6 and Figure 7 As shown, near 30 GHz, the amplitude part of the reflection coefficient S12 in the two states is basically equal, and there is a gain of more than 4 dB, while the phase difference is 180°, which meets the design goal of the gain-coded metasurface.

[0052] In the passive state, for the same metasurface array, when x-polarized electromagnetic waves are incident vertically, an array structure with a coding sequence of 0110011001 is designed, in which each column of units is combined into a sub-array for array arrangement. When the operating frequency is 30GHz, the three-dimensional far-field scattering pattern of the metasurface is as follows: Figure 8 As shown. Figure 8 As can be seen, the regular reflected beam is significantly suppressed and transformed into two scattered beams at oblique angles, each forming a 30° angle with the z-axis. When loaded with a power amplifier, the metasurface unit achieves the same 1-bit performance and possesses active amplification properties, enabling controllable angle-of-reflection of the reflected signal.

[0053] Example 2: Figure 3The structural unit shown has a period of p = 5000um for the square unit and a width of p1 = 2650um for the rectangular radiation patch. The microstrip line lengths are l1 = 3450um, l2 = 1200um, l3 = 1800um, and l4 = 900um, and the microstrip width is w = 200um. 1400um and 920um are reserved between the four microstrip sections as interfaces for the MOS switch chip and the amplifier chip, respectively. The chip and the microstrip are bonded with gold wires. The dimensions of the horizontal hourglass slot and the vertical hourglass slot are a1 = 300um, a2 = 425um, b1 = 100um, b2 = 1000um and a3 = 300um, a4 = 425um, b3 = 100um, and b4 = 740um, respectively. The substrates are RO4350B and Rogers RO4450F. The dielectric structure consists of five overlapping PP layers, with a center layer thickness of h2 = 200 μm and the remaining layers of h1 = 100 μm. Between each layer, a 35 μm thick copper layer serves as the routing for control and power lines. The outermost microstrip and rectangular patch layers have a copper thickness of 18 μm. By switching the MOS switch chip on and off, the "0" and "1" states under different polarizations are achieved.

[0054] In the passive state, for the same metasurface array, when x-polarized electromagnetic waves are incident vertically, an array structure with a coding sequence of 0111000111 is designed, in which each column of units is combined into a sub-array for array arrangement. When the operating frequency is 30GHz, the three-dimensional far-field scattering pattern of the metasurface is as follows: Figure 9 As shown. Figure 9 As can be seen, the regular reflected beam is significantly suppressed and transformed into two scattered beams at oblique angles, each forming a 20° angle with the z-axis. When loaded with a power amplifier, the metasurface unit achieves the same 1-bit performance and possesses active amplification properties, enabling controllable angle-of-reflection of the reflected signal.

[0055] According to an embodiment of the present invention, a MOS switch-controlled gain millimeter-wave programmable metasurface is proposed. This structure implements a reflective metasurface unit with an integrated power amplifier and MOS switch chip. This unit receives x-polarized waves in a high-isolation dual-polarized rectangular patch antenna unit structure, amplifies them through microstrip transmission, and re-radiates them as y-polarized waves. By adjusting the on / off switching of the MOS switch chip, the y-polarized reflection phase can be changed. This enables active signal amplification while achieving excellent 1-bit performance, thereby achieving coding state switching of the metasurface unit and far-field beam steering of the metasurface array. This is a millimeter-wave artificial electromagnetic surface with active amplification capabilities, which is expected to solve the path loss and reflection loss problems of current reflective metasurfaces, as well as the RF signal leakage caused by programmable metasurface bias circuits. It has important potential applications in intelligent communications, imaging, and computing technologies.

[0056] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0057] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "N" means at least two, such as two, three, etc., unless otherwise specifically defined.

Claims

1. A millimeter-wave gain programmable metasurface controlled by MOS switches, characterized in that: The metasurface is composed of a two-dimensional array of multiple subwavelength units, each of which includes a radiation patch (1), a microstrip radio frequency link (2), a substrate (3), a power amplifier chip (7), a MOS switch chip (8) and a slotted metal backplane (4); The radiation patch (1) is arranged on the top layer of the sub-wavelength unit and is etched on the substrate; The microstrip radio frequency link (2) is arranged at the bottom layer of the subwavelength unit and is located on the back side of the substrate; The substrate (3) is a multi-layer dielectric structure, with a metal structure layer (6) between each dielectric layer; A slotted metal backplane (4) is etched on a metal structure layer between a bottom layer and a sub-bottom layer medium, and is separated from a microstrip radio frequency link by a layer of medium; three hourglass-shaped radiation slots (5) are provided on the metal backplane, wherein the vertically opened radiation slot is located at the center of the backplane and is arranged orthogonally to the other two horizontally opened hourglass-shaped radiation slots; The power amplifier chip (7) and two MOS switch chips (8) are attached to the back of the substrate and bonded to the microstrip radio frequency link by gold wires.

2. The MOS switch-controlled gain millimeter-wave programmable metasurface according to claim 1, characterized in that: The radiation patch has a rectangular structure, is made of copper, and operates at the millimeter wave frequency band.

3. The MOS switch-controlled gain millimeter-wave programmable metasurface according to claim 1, characterized in that: The substrate is a five-layer dielectric structure of Rogers RO4350B and Rogers RO4450F overlapping each other, with the top layer being Rogers RO4450F. The dielectric constants are 3.66 and 3.7, and the loss tangents are 0.0037 and 0.004, respectively.

4. The MOS switch-controlled gain millimeter-wave programmable metasurface according to claim 1, characterized in that: The materials used for the underlying microstrip RF link and the slotted metal backplane are copper. The slotted metal backplane uses hourglass-shaped slots to ensure that the electromagnetic energy is efficiently coupled to the underlying microstrip transmission link. After amplification by the power amplifier, the MOS switch selects the channel. The two channels lead to two hourglass-shaped radiation slots orthogonal to the central slot. The two radiation slots are fed in opposite phases to achieve a 180° phase difference while implementing secondary radiation.

5. The MOS switch-controlled gain millimeter-wave programmable metasurface according to claim 1, characterized in that: According to different functional requirements, different coding arrangements are calculated, and the distribution of bias voltage is programmed and controlled using a field programmable gate array to reconstruct the reflection phase distribution.

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