CN110808472A - Digital coding unit based on power amplification and super surface - Google Patents

Abstract

The invention relates to a digital encoding unit and a metasurface based on power amplification, wherein the digital encoding unit includes a first metal structure layer, a first dielectric plate layer, a metal ground, a second dielectric plate layer and The second metal structure layer, the first metal structure layer and the second metal structure layer each include a patch, a first metal wire, a second metal wire, a third metal wire and a fourth metal wire, and one end of the first metal wire is connected to the The frame of the chip is connected, the other end is connected to the first end of the power amplifier, the second end of the power amplifier is connected to the second metal wire, the third end of the power amplifier is connected to the third metal wire, and the fourth metal wire is connected. One end is connected between two ends of the first metal wire. Compared with the prior art, in the present invention, a power amplifier with controllable operating voltage is arranged in the digital coding unit, and the voltage is controlled by the digital coding method, so that arbitrary modulation of the transmitted electromagnetic wave energy can be realized.

Description

A digital coding unit and metasurface based on power amplification

technical field

The invention relates to the technical field of novel artificial electromagnetic materials, in particular to a power amplification-based digital coding unit and a metasurface.

Background technique

A metasurface is an artificial two-dimensional structure composed of subwavelength basic units, and the amplitude and phase changes of the emitted, reflected and scattered waves can be obtained at the interface of the metasurface. By controlling the amplitude and phase response of each basic unit, metasurfaces can effectively control electromagnetic waves in a variety of ways, which are widely used in flat lenses, complete absorbers, imaging, and detection fields. In recent years, the concept of digitally encoded metasurfaces has been proposed, by introducing digital features to describe cells with digitally encoded "0" and "1" to represent opposite phase responses. Digitally encoded metasurfaces offer an easier way to control electromagnetic waves.

Amplitude-modulated metasurfaces, as an important means of controlling electromagnetic waves, have been demonstrated to have the ability to control the intensity of diffraction orders, tune acoustic radiation patterns, and optical holography. For passive metasurfaces, the most commonly used method of amplitude modulation is to change the conduction mechanism to achieve dynamic beam steering, fully absorbing, multifunctional photonic switching. However, this passive surface can only subtract the energy of electromagnetic waves in space, which limits the application potential of metasurfaces to control electromagnetic waves.

The traditional control of electromagnetic wave energy mainly focuses on attenuation modulation, lack of delta modulation, the only way to enhance the energy is to increase the power of the source, the energy increase in this way is limited, and it needs to increase the work load of the feed source. At present, some studies have introduced an amplifier circuit into the metasurface, but its function is mainly reflected in the non-reciprocity, and the modulation characteristics of the active amplifier are ignored, and the arbitrary modulation of the energy of the space propagating wave cannot be truly realized.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a digital coding unit and metasurface based on power amplification in order to overcome the above-mentioned defects in the prior art. By using an active amplifier, by controlling the voltage of the power amplifier, arbitrary modulation of the spatial wave amplitude can be realized.

The purpose of the present invention can be achieved through the following technical solutions: a digital encoding unit based on power amplification, comprising a first metal structure layer, a first dielectric plate layer, a metal ground, and a second dielectric plate layer arranged in sequence from top to bottom and a second metal structure layer, the first metal structure layer and the second metal structure layer each include a patch, a first metal wire, a second metal wire, a third metal wire and a fourth metal wire, the first metal wire One end of the wire is connected to the frame of the patch, the other end is connected to the first end of the power amplifier, the second end of the power amplifier is connected to the second metal wire, and the third end of the power amplifier is connected to the third metal wire wires are connected, one end of the fourth metal wire is connected between two ends of the first metal wire, the power amplifier of the first metal structure layer is also connected to the top surface of the first dielectric plate layer, the second The power amplifier of the metal structure layer is also connected to the bottom surface of the second dielectric plate layer.

Further, the power amplifier includes four working voltages, the four working voltages respectively correspond to four digital codes with different amplitudes, and the four digital codes with different amplitudes respectively correspond to four kinds of spatial energy amplitudes.

Further, the four working voltages include 5V, 4.2V, 3.8V and 3V, and the corresponding four digital codes with different amplitudes are "00", "01", "10" and "11" in turn, and the corresponding four The spatial energy amplitudes are -10dB, 0dB, 10dB and 20dB in turn.

Further, the period length of the digital encoding unit is 39-41 mm, the thicknesses of the first dielectric plate layer and the second dielectric plate layer are both 0.9-1.1 mm, and the first dielectric plate layer and the second dielectric plate layer are both 0.9-1.1 mm. The layers use the same medium, the dielectric constant is 2.45-2.85, and the loss tangent is -0.002-0.004.

Further, the period length of the digital encoding unit is 40 mm, and the thicknesses of the first dielectric plate layer and the second dielectric plate layer are both 1 mm.

Further, the fourth metal wire and the first metal wire are perpendicular to each other, and the first metal wire and the third metal wire are both parallel to the second metal wire.

Further, the patch is a circular patch.

Further, the radius of the circular patch is 10.28-10.48 mm.

Further, the radius of the circular patch is 10.38mm.

A digital encoding metasurface based on power amplification, the metasurface includes N×N digital encoding units arranged in a square matrix, wherein N is a non-zero positive integer.

Compared with the prior art, from the perspective of digital coding, the present invention sets up a power amplifier including a plurality of working voltages in the digital coding unit, and controls the working voltage of the power amplifier to determine the amplification level of the power amplifier, thereby making the metasurface. The space energy of the transmitting beam can be modulated to a desired value, which can not only attenuate the energy of the electromagnetic wave, but also enhance the energy of the electromagnetic wave according to the needs, so as to realize any modulation of the energy of the transmitted electromagnetic wave.

Description of drawings

Fig. 1a is the front structure schematic diagram of the digital coding unit of the present invention;

Fig. 1b is the reverse structure schematic diagram of the digital coding unit of the present invention;

Fig. 2 is the cross-sectional structure schematic diagram of the digital coding unit of the present invention;

Fig. 3 is the three-dimensional structure schematic diagram of the digital coding unit of the present invention;

Fig. 4 is the S-parameter simulation result of the metasurface in the embodiment;

Fig. 5 is the near and far field simulation result of digital coding unit under four kinds of working voltages in the embodiment;

Fig. 6 is the far-field simulation result graph of metasurface under four kinds of working voltages in the embodiment;

Fig. 7 is the far-field experiment test result diagram of the metasurface under four kinds of working voltages in the embodiment;

Description of the symbols in the figure: 1. The first metal structure layer, 11, the patch, 12, the first metal wire, 13, the second metal wire, 14, the third metal wire, 15, the fourth metal wire, 2, the power amplifier , 3, the first dielectric plate layer, 4, the metal ground, 5, the second dielectric plate layer, 6, the second metal structure layer.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

As shown in Fig. 1a, Fig. 1b, Fig. 2 and Fig. 3, a digital coding unit based on power amplification includes a first metal structure layer 1, a first dielectric plate layer 3, and a metal ground 4 arranged in sequence from top to bottom , the second dielectric plate layer 5 and the second metal structure layer 6, wherein, the first metal structure layer 1 and the second metal structure layer 6 both include a patch 11, a first metal wire 12, a second metal wire 13, a third The metal wire 14 and the fourth metal wire 15, one end of the first metal wire 12 is connected to the frame of the patch 11, the other end is connected to the first end of the power amplifier 2, and the second end of the power amplifier 2 is connected to the second metal wire The wire 13 is connected, the third end of the power amplifier 2 is connected to the third metal wire 14, one end of the fourth metal wire 15 is connected between the two ends of the first metal wire 12, and the power amplifier of the first metal structure layer 1 is also Connected to the top surface of the first dielectric plate layer 3, the power amplifier of the second metal structure layer 6 is also connected to the bottom surface of the second dielectric plate layer 5, wherein, in FIG. 1a and FIG. 1b, the radio frequency signals (RF ) in the emission direction.

In this embodiment, the patch 11 is a circular patch, the radius R is 10.38mm, the first dielectric plate layer 3 and the second dielectric plate layer 5 use the same medium, the dielectric constant is 2.45-2.85, and the loss tangent is 0.002 ~0.004, the thickness h of the first dielectric plate layer 3 and the second dielectric plate layer 5 is 1 mm, and the period length a of the entire digital encoding unit is 40 mm.

The digital coding unit has 4 kinds of working voltages. By applying different power supply voltages to control the amplification level of the power amplifier 2, 4 kinds of spatial energy amplitudes of the transmitting beam are obtained. The 4 spatial energy amplitudes correspond to 4 digital state codes with different amplitudes. By controlling the voltage of the power amplifier 2, the modulation of the spatial wave amplitude can be realized. Among them, the four digital state codes are "00", "01", "10" and "11" respectively, which respectively represent the digital state of the amplitude of the electromagnetic wave transmitted by the digital encoding unit, and the four digital state codes of different amplitudes correspond to four kinds of Spatial energy amplitude, 4 kinds of spatial energy amplitude are -10dB, 0dB, 10dB and 20dB respectively.

That is: among the working voltages of the four digital coding units, "00" corresponds to the working voltage of the power amplifier 2, which is 5V, "01" corresponds to the working voltage of the power amplifier 2, which is 4.2V, and "10" corresponds to the working voltage of the power amplifier 2. is 3.8V, "11" corresponds to the operating voltage of the power amplifier 2 is 3V.

In the present invention, by applying specific control voltages to the power amplifier, the spatial energy of the transmit beam can be modulated to desired values, and these specific amplitudes can be further encoded into digital "00", "01", "10" or "11", and these digital codes represent a certain amount of information to clearly distinguish the magnitude of the transmitted wave amplitude.

The S-parameters of the digital coding unit are simulated, and the simulation results shown in Figure 4 are obtained. The return loss values represented by S11 are all lower than 0dB. Combined with the insertion loss values represented by S21, it shows that the combination of electromagnetic components and power amplifiers, A larger transmission coefficient can be achieved; the near-field and far-field simulation results of the digital coding unit are normalized and compared. As can be seen from Figure 5, after the same amount of space electromagnetic wave energy passes through 4 different digital coding units, there will be Different degrees of energy amplification.

The metasurface of this embodiment is composed of 7×7 digital coding units, and 98 power amplifiers are integrated in total. The metasurface is fabricated by PCB technology, and the power amplifier and other components are assembled by machine welding, which makes the metasurface simple and inexpensive to manufacture, and can be easily fabricated in the microwave frequency band. To test the far-field results in the two-dimensional (2D) plane, experiments were performed in a standard darkroom.

As shown in Figure 6 and Figure 7, the comparison between the far-field simulation results and the experimental measurement results of the metasurface at four different operating voltages, that is, four different amplification levels, is obtained. Rectangular horns of the same size. The measured results are in good agreement with the simulation results, and four different amplification levels from -10dB to 20dB are achieved. It is shown that the encoding metasurface based on the power amplifier in the present invention can amplify the energy of space electromagnetic waves, and the amplification level of the power amplifier can be determined by the power supply voltage. This property not only attenuates the electromagnetic wave energy, but also enhances the electromagnetic wave energy as needed, thus enriching the methods of energy modulation and broadening the application prospects for active and programmable metasurfaces.

To sum up, the present invention is different from the traditional scheme of using equivalent medium parameters to analyze and design the metasurface, and analyzes and designs the digital encoding unit from the perspective of digital encoding, which greatly simplifies the design process;

The invention controls the transmission state of the metasurface unit by controlling the power supply voltage of the power amplifier, so that the designed electromagnetic metasurface has a programmable function;

The invention adopts a controllable digital coding unit, and by controlling the power supply voltage, the amplification level of the power amplifier is determined, and the arbitrary control of the energy of the space propagating wave is realized;

The invention is simple to process and easy to realize, and can be easily prepared and processed in the microwave frequency band only by means of a simple metal pattern.

Claims (10)

1. A digital encoding unit based on power amplification, characterized in that it comprises a first metal structure layer (1), a first dielectric plate layer (3), a metal ground (4), a second A dielectric plate layer (5) and a second metal structure layer (6), the first metal structure layer (1) and the second metal structure layer (6) both include a patch (11) and a first metal wire (12) , a second metal wire (13), a third metal wire (14) and a fourth metal wire (15), one end of the first metal wire (12) is connected to the frame of the patch (11), and the other end connected to the first end of the power amplifier (2), the second end of the power amplifier (2) is connected to the second metal wire (13), and the third end of the power amplifier (2) is connected to the third metal wire ( 14) are connected, one end of the fourth metal wire (15) is connected between the two ends of the first metal wire (12), and the power amplifier (2) of the first metal structure layer (1) is also connected to the first metal wire (12). The top surface of a dielectric plate layer (3) is connected, and the power amplifier (2) of the second metal structure layer (6) is also connected to the bottom surface of the second dielectric plate layer (5). 2. A kind of digital coding unit based on power amplification according to claim 1, is characterized in that, described power amplifier (2) comprises four working voltages, and described four working voltages correspond to four numbers of different amplitudes respectively The four digital codes with different amplitudes correspond to the four spatial energy amplitudes respectively. 3. a kind of digital coding unit based on power amplification according to claim 2, is characterized in that, described four working voltages comprise 5V, 4.2V, 3.8V and 3V, and corresponding digital codes of four different amplitudes are successively are "00", "01", "10" and "11", and the corresponding four spatial energy amplitudes are -10dB, 0dB, 10dB and 20dB in turn. 4. A digital encoding unit based on power amplification according to claim 1, characterized in that, the period length of the digital encoding unit is 39-41 mm, the first medium plate layer (3) and the second medium The thickness of the board layer (5) is 0.9-1.1 mm, the first dielectric board layer (3) and the second dielectric board layer (5) are made of the same medium, the dielectric constant thereof is 2.45-2.85, and the loss tangent is -0.002 to 0.004. 5. The digital encoding unit based on power amplification according to claim 4, wherein the period length of the digital encoding unit is 40mm, and the first dielectric plate layer (3) and the second dielectric plate layer (5) The thicknesses are all 1 mm. 6. The digital encoding unit based on power amplification according to claim 1, wherein the fourth metal wire (15) and the first metal wire (12) are perpendicular to each other, and the first metal wire ( 12) and the third metal wire (14) are both parallel to the second metal wire (13). 7. The power amplification-based digital encoding unit according to claim 1, wherein the patch (11) is a circular patch. 8 . The digital encoding unit based on power amplification according to claim 7 , wherein the radius of the circular patch is 10.28-10.48 mm. 9 . 9 . The digital encoding unit based on power amplification according to claim 8 , wherein the radius of the circular patch is 10.38 mm. 10 . 10. A digital coding metasurface based on power amplification, wherein the metasurface is composed of N×N digital coding units as claimed in claim 1 arranged in a square matrix, wherein N is a non-zero positive Integer.

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