A high power phase reconfigurable intelligent reflecting surface

Abstract

The application discloses a high-power phase reconfigurable intelligent reflecting surface which is composed of array elements with the same structure; the array element comprises a receiving / transmitting unit, a coupling structure and a phase modulation circuit; the receiving / transmitting unit, the coupling structure and the phase modulation circuit are sequentially arranged to form a laminated structure; the receiving / transmitting unit is used for converting a free space electromagnetic wave into an electric field on the unit or converting a field from the coupling structure into a free space electromagnetic wave and radiating; the coupling structure converts the electric field into a guided wave which is transmitted to the phase modulation circuit, and converts a guided wave from the phase modulation circuit into an electric field on the receiving / transmitting unit; and the phase modulation circuit uniquely determines a shift operation of the guided wave according to an applied direct current voltage to add a specific additional phase. While realizing 360-degree phase control, the application has higher power capacity, and is expected to be widely applied in a high-power incident scene of the intelligent reflecting surface.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and in particular to the application technology of metasurfaces in high-power scenarios. Background Technology

[0002] Traditional reflective array antennas or phase-modulated metasurfaces have fixed phase responses for each element, and the phase arrangement of the entire array is fixed, thus limiting their functionality. To dynamically adjust the phase response of the array elements, the traditional method involves loading active devices onto the elements and designing various electromagnetic resonant structures for different parameters of these active devices under different states. Different phase responses are then achieved by dynamically controlling and switching between different equivalent electromagnetic resonant structures on the elements.

[0003] Due to limitations in design principles, when analyzing and designing equivalent electromagnetic structures, the equivalent resonant current only flows through the active device when the electric field of the equivalent resonant structure on the array element is parallel to the active device. Only then is the active device considered to participate in electromagnetic resonance and perform its pre-designed function. Under high-power electromagnetic wave incidence, the electric field parallel to the device will generate a potential difference across the device, inducing a large instantaneous voltage that may cause device breakdown. The strong resonant current flowing through the active device and interacting with its equivalent resistance will generate significant heat loss, potentially burning out the device. Therefore, traditional methods of designing reconfigurable equivalent resonant circuits based on active devices often face the challenge of reducing input power to protect the devices, making them difficult to apply under high-power conditions.

[0004] In summary, reconfigurable metasurfaces designed using traditional methods are difficult to apply under high-power conditions. Summary of the Invention

[0005] To address the challenge of applying current reconfigurable metasurface technology under high-power conditions, this invention provides a high-power phase-reconfigurable smart reflective surface. This reflective surface is based on a non-resonant structure and a high-power capacity reconfigurable metasurface array element design. Considering practical applications, this invention should have phase control capabilities for various electromagnetic waves and completely independent phase control for multiple incident waves.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A high-power phase-reconfigurable smart reflective surface is composed of array elements with identical structures;

[0008] The array element includes a receiving / transmitting unit, a coupling structure, and a phase modulation circuit, which are arranged in sequence to form a stacked structure.

[0009] The receiving / transmitting unit is used to convert electromagnetic waves in free space into a distributed electric field, and to convert the phase-modulated electric field, after being converted by the coupling structure, into electromagnetic waves in free space and radiate them. The coupling structure is used to convert the electric field on the receiving / transmitting unit into a guided wave and transmit it to the phase modulation circuit, and to convert the phase-modulated guided wave from the phase modulation circuit into a field on the receiving / transmitting unit. The phase modulation circuit consists of several microstrip lines and active devices, and is used to add an extra phase to the input guided wave before outputting it. The magnitude of the added extra phase is controlled by the applied DC voltage.

[0010] The array element performs phase control on the incident wave under an applied voltage. The coupling structure is used to convert the electric field on the receiving / transmitting unit into a guided wave, and the phase modulation circuit realizes the phase modulation function.

[0011] As a further improvement of the present invention, the coupling structure may take the form of a via, a probe, or a slit.

[0012] As a further improvement of the present invention, the receiving / transmitting unit includes a top-layer patch and a dielectric, and a ground plane, wherein the patch, dielectric, and ground plane are arranged sequentially to form a microstrip antenna.

[0013] As a further improvement of the present invention, the array elements are arranged in a pre-designed shape, which is a uniformly distributed rectangular array, circular array, hexagonal array, octagonal array, or randomly distributed array.

[0014] As a further improvement of the present invention, the active device is a pure reactance, and the guided wave of the active device propagates along the microstrip line, interacting with the active device to achieve phase modulation.

[0015] As a further improvement of the present invention, each part of the phase modulation circuit consists of two varactor diodes and a microstrip line, with the two varactor diodes connected in parallel via a quarter-wavelength microstrip line; this is used to adjust the equivalent capacitance of the varactor diode by adjusting the reverse bias voltage applied to the varactor diode by the DC bias line, thereby adjusting the additional phase of the phase modulation circuit.

[0016] As a further improvement of the present invention, the active device of the phase modulation circuit is electrically connected by a metal wire for applying a DC bias voltage. The phase modulation circuit is used to change the terminal impedance to add different additional phases to the reflected wave of the guided wave when a DC voltage is applied.

[0017] As a further improvement of the present invention, the active device of the phase modulation circuit is parallel to the direction of the guided wave, and the electric field of the guided wave is confined in the medium between the microstrip line and the dielectric substrate. Part of the electric field passes through the active device and forms a potential difference across the active device through induction.

[0018] Compared with the prior art, the present invention has the following technical effects:

[0019] Compared to traditional resonant reconfigurable metasurface array elements, the array element of this invention consists of a receiving / transmitting unit, a coupling structure, and a phase modulation circuit. This invention, through a specifically designed receiving / transmitting unit, converts free-space electromagnetic waves into guided waves, and achieves phase control via a phase modulation circuit controlled by an external DC voltage. The waves are then radiated into free space through the receiving / transmitting unit. The special design of the receiving / transmitting unit enables phase control of electromagnetic waves with arbitrary polarization, achieving a wider polarization application range and greater flexibility in independent polarization adjustment compared to traditional methods. The design of the phase modulation circuit allows for up to 360° of complete phase coverage, meeting the needs of practical applications. The phase control function of this invention primarily stems from the design of the phase modulation circuit rather than the electromagnetic resonant structure itself, addressing the issue of large electric fields and resonant currents exceeding the limits of active devices, thus achieving high power capacity. This invention is expected to find widespread application in high-power reconfigurable metasurfaces and smart reflective surfaces. Attached Figure Description

[0020] Figure 1 This is the basic structure of a high-power phase-reconfigurable smart reflective surface as described in this invention;

[0021] Figure 2 This is a diagram of a high-power phase-reconfigurable smart reflective surface structure according to the present invention;

[0022] Figure 3 This is an example of the amplitude response of an embodiment of the present invention;

[0023] Figure 4 The phase response is an embodiment of the present invention;

[0024] Figure 5 The amplitude response and phase response at 2.6 GHz are shown in one embodiment of the present invention.

[0025] Figure 6 This is a local electric field vector diagram (yoz profile) at an active device according to an embodiment of the present invention;

[0026] Figure 7 This is a local electric field vector diagram (xoz profile) at an active device according to an embodiment of the present invention;

[0027] Figure 8 This is a scalar diagram (yoz profile) of the local electric field components at the active device according to an embodiment of the present invention;

[0028] Figure 9 This is a scalar diagram (xoz profile) of the local electric field components at the active device in an embodiment of the present invention. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0030] like Figure 1 As shown, the high-power phase-reconfigurable smart reflective surface of this invention is composed of array elements with identical structures. The array elements are characterized by their ability to control the phase of the incident wave under an applied voltage and possess high power capacity. Each array element includes a receiving / transmitting unit 1, a coupling structure 2, and a phase modulation circuit 3, which are arranged sequentially to form a stacked structure.

[0031] The power capacity refers to the maximum incident electromagnetic wave power that the structure can withstand without fundamentally changing its phase control properties.

[0032] The receiving / transmitting unit 1 is used to convert electromagnetic waves from free space into an electric field distributed on the unit. Depending on the nature of the received electromagnetic waves, the receiving / transmitting unit 1 can receive and transmit various forms of electromagnetic waves, including but not limited to linearly polarized, double-linearly polarized, circularly polarized, and double-circularly polarized electromagnetic waves. For guided waves that have been phase-modulated by a phase-modulation circuit, after being converted into an electric field via a coupling structure, the receiving / transmitting unit converts the electric field into free-space electromagnetic waves and radiates them.

[0033] The coupling structure 2 converts the electric field from the receiving / transmitting unit 1 into a guided wave and couples it to the phase modulation circuit 3, and converts the phase-modulated guided wave from the phase modulation circuit 3 into an electric field on the receiving / transmitting antenna 1.

[0034] The coupling structure 2 may include, but is not limited to, via coupling structure, slot coupling structure, probe coupling structure, etc., depending on the design requirements.

[0035] The phase modulation circuit 3 consists of several microstrip lines and active devices. Under the control of an applied DC voltage, it can be equivalent to different terminating impedances, achieving phase control through the terminal reflection of the guided wave. The phase modulation circuit 3, composed of several microstrip lines and active devices, is used to add an extra phase to the input guided wave before outputting it. The magnitude of the added extra phase is controlled by the applied DC voltage. Since the guided wave propagating on the microstrip line is similar to a transverse electromagnetic wave, i.e., the electric and magnetic fields of the guided wave are approximately perpendicular to the direction of propagation, for active devices parallel to the direction of the guided wave, the potential difference across the active device caused by the guided wave and the current through the active device are relatively small. Therefore, it can withstand incident waves with higher power and achieve a larger power capacity.

[0036] The active devices are electrically connected by metal wires and can be subjected to a manually controlled DC bias voltage. The phase modulation circuit can be regarded as a variable impedance controlled by the applied DC bias voltage. As the terminal load of the pre-coupling structure 2, the terminal impedance can be changed under the control of the applied DC voltage, thereby adding different additional phases to the reflected wave of the guided wave.

[0037] Specifically, the input of this invention is an electromagnetic wave from free space, and its function is to perform phase control on the input free space electromagnetic wave, add an additional phase controlled by an external DC voltage, and the output of the system is a phase-modulated free space electromagnetic wave.

[0038] This invention can perform completely independent phase control on any number of free-space electromagnetic waves of any frequency and polarization.

[0039] This invention can achieve an arbitrary phase modulation range of up to 360°, and within this range, arbitrary phase control can be achieved. Under the condition of multiple incident electromagnetic waves, completely independent phase control can be performed on each incident wave.

[0040] The phase control method of this invention is based on the non-resonant principle. After the electric field on the receiving / transmitting unit 1 is converted into a guided wave, the phase modulation circuit 3 realizes the phase modulation function. Due to the special distribution of the guided wave electric field on the phase modulation circuit 3, a large power capacity can be achieved.

[0041] The structure used in the implementation of this embodiment is as follows: Figure 2 As shown. In this example, the receiving / transmitting unit 1 is a microstrip antenna composed of a top-layer patch, a dielectric, and a ground plane. It is a dual-polarized antenna. The receiving / transmitting unit 1 receives electromagnetic waves from free space and converts them into an electric field on the metal patch.

[0042] The system's input is electromagnetic waves from free space. Its function is to perform phase control on the input free space electromagnetic waves, adding an additional phase controlled by the user. The system's output is electromagnetic waves from free space.

[0043] By designing the receiving / transmitting unit 1, the high-power phase-reconfigurable smart reflective surface can receive and transmit electromagnetic waves of different frequencies with single-line polarization, double-line polarization, single-circular polarization, or double-circular polarization, and can achieve independent phase control for electromagnetic waves with different incident polarizations.

[0044] The array elements are arranged according to a pre-designed pattern, including but not limited to uniformly distributed rectangular arrays, circular arrays, hexagonal arrays, octagonal arrays, etc., as well as randomly distributed arrays.

[0045] The phase control effect of its array elements is uniquely determined by the applied DC voltage. The phase control of the array elements is based on the non-resonant principle. After the coupling structure 2 converts the electric field on the receiving / transmitting unit 1 into a guided wave, the phase modulation circuit 3 realizes the phase modulation function. Due to the special distribution of the guided wave electric field on the phase modulation circuit 3 and the total reflection formed by the guided wave and the active device, the high-power phase-reconfigurable intelligent reflective surface has a large power capacity while realizing the basic phase modulation function.

[0046] Specifically, the input of this invention is an electromagnetic wave from free space, and its function is to perform phase control on the input free space electromagnetic wave, add an additional phase controlled by an external DC voltage, and the output of the system is a phase-modulated free space electromagnetic wave.

[0047] This invention can perform completely independent phase control on any number of free-space electromagnetic waves of any frequency and polarization.

[0048] This invention can achieve an arbitrary phase modulation range of up to 360°, and within this range, arbitrary phase control can be achieved. Under the condition of multiple incident electromagnetic waves, completely independent phase control can be performed on each incident wave.

[0049] The phase control method of this invention is based on the non-resonant principle. After the electric field on the receiving / transmitting unit 1 is converted into a guided wave, the phase modulation circuit 3 realizes the phase modulation function. Due to the special distribution of the guided wave electric field on the phase modulation circuit 3, a large power capacity can be achieved.

[0050] The structure used in the implementation of this embodiment is as follows: Figure 2 As shown. In this example, the receiving / transmitting unit 1 is a microstrip antenna composed of a top-layer patch, a dielectric, and a ground plane. It is a dual-polarized antenna. The receiving / transmitting unit 1 receives electromagnetic waves from free space and converts them into an electric field on the metal patch.

[0051] The system's input is electromagnetic waves from free space. Its function is to perform phase control on the input free space electromagnetic waves, adding an additional phase controlled by the user. The system's output is electromagnetic waves from free space.

[0052] By designing the receiving / transmitting unit 1, the high-power phase-reconfigurable smart reflective surface can receive and transmit electromagnetic waves of different frequencies with single-line polarization, double-line polarization, single-circular polarization, or double-circular polarization, and can achieve independent phase control for electromagnetic waves with different incident polarizations.

[0053] The array elements are arranged according to a pre-designed pattern, including but not limited to uniformly distributed rectangular arrays, circular arrays, hexagonal arrays, octagonal arrays, etc., as well as randomly distributed arrays.

[0054] The phase control effect of its array elements is uniquely determined by the applied DC voltage. The phase control of the array elements is based on the non-resonant principle. After the coupling structure 2 converts the electric field on the receiving / transmitting unit 1 into a guided wave, the phase modulation circuit 3 realizes the phase modulation function. Due to the special distribution of the guided wave electric field on the phase modulation circuit 3 and the total reflection formed by the guided wave and the active device, the high-power phase-reconfigurable intelligent reflective surface has a large power capacity while realizing the basic phase modulation function.

[0055] The via connecting the top-layer patch and the phase modulation circuit 3 serves as coupling structure 2, converting the electric field of the two linearly polarized incident waves on the top-layer patch into guided waves and coupling them into the two entrances of the bottom-layer phase modulation circuit 3. The bottom-layer phase modulation circuit 3 is a reflective phase modulation circuit, consisting of two identical parts, each corresponding to one of the two polarized incident guided waves. Each part consists of two varactor diodes and a microstrip line. The two varactor diodes are connected in parallel through a quarter-wavelength microstrip line, which can achieve a phase modulation range more than twice that of a single varactor diode. According to transmission line theory, the varactor diode can be approximated as a purely reactive load, and the microstrip line can be approximated as a purely resistive transmission line. Therefore, when the guided wave propagates along the microstrip line, it interacts with the varactor diode to achieve total reflection. By adjusting the reverse bias voltage applied to the varactor diode by the DC bias line, the equivalent capacitance of the varactor diode (capacitance variation range 0.63-2.67pF) can be adjusted, thereby adjusting the additional phase of the phase modulation circuit 3. The inlet of the reflective phase modulation circuit 3 is also its outlet. The guided wave, with added phase, is coupled to the top layer patch via a via. The top layer patch and dielectric then act as the transmitting unit, emitting the via-coupled guided wave into free space. The specific structural dimensions were obtained through electromagnetic simulation.

[0056] As an optional embodiment of the present invention, the phase modulation circuit 3 is composed of a microstrip line and an active device. The active device acts as a pure reactance, and the guided wave propagates along the microstrip line, interacting with the active device to achieve phase modulation. The active device of the phase modulation circuit (3) is parallel to the direction of the guided wave, while most of the electric field of the guided wave is confined in the dielectric between the microstrip line and the dielectric substrate. Only a small portion of the electric field passes through the active device, and a potential difference is formed across the active device through induction.

[0057] When a guided wave propagates along a microstrip line, most of the electric field is confined within the medium between the microstrip line and the ground plane, with only a small portion of the electric field parallel to the propagation direction. In contrast, an active device propagates parallel to the guided wave, with only a small portion of the electric field inducing a potential difference across its terminals. When this induced potential difference exceeds the withstand voltage limit of the active device, the phase modulation circuit will be damaged. Therefore, array elements can accept incident waves of higher power, achieving greater power capacity.

[0058] Through careful design, this embodiment can receive linearly polarized incident free-space electromagnetic waves and perform phase control. To verify the correctness of this embodiment, the amplitude and phase response of the unit under plane wave incident conditions are simulated. Since the unit structure in this embodiment has symmetry, that is, the electromagnetic response structures in the two linear polarization directions are exactly the same, and the two can be independently controlled, without loss of generality, it is only necessary to verify the response effect of one of the polarizations in this embodiment.

[0059] With the capacitance value of the varactor diode adjusted by an applied voltage, the simulation results show the amplitude response obtained by adjusting the capacitance value of the varactor diode in the vertical polarization direction (y direction in this embodiment) as follows: Figure 3 As shown in the figure. This embodiment achieved good amplitude response in the 2.5-2.7 GHz range.

[0060] In this embodiment, the phase response obtained by adjusting the capacitance of the varactor diode in the vertical polarization direction is as follows: Figure 4 As shown. This embodiment achieves a near-linear phase response in the 2.5-2.7 GHz range, with a phase modulation range of 356° at the center frequency of 2.6 GHz, realizing a wide range of phase modulation.

[0061] like Figure 5 The figure shows the phase and amplitude response obtained by adjusting the capacitance of the varactor diode in the vertical polarization direction at the design operating frequency of 2.6 GHz in this embodiment.

[0062] Figure 3 , Figure 4 , Figure 5 This demonstrates that the amplitude response and phase control of this embodiment are no less effective than traditional methods and can meet the needs of practical applications.

[0063] Figure 6 This is a local electric field diagram (yoz profile) at the active device in this embodiment, where the direction of the electric field is indicated by arrows and the electric field intensity is represented by colors. In the figure, the direction of the guided wave and the orientation of the active device are in the x-direction. The electric field energy is concentrated and confined in the dielectric region between the microstrip line and the ground plane, with only a small portion propagating along the x-direction.

[0064] Figure 7This is a local electric field diagram (xoz profile) at the active device in this embodiment, where the electric field direction is indicated by arrows and the electric field intensity is represented by colors. In the figure, the direction of the guided wave and the orientation of the active device are in the x-direction. The electric field energy is concentrated and confined in the dielectric region between the microstrip line and the ground plane, with only a small portion propagating along the x-direction.

[0065] Figure 8 This is a diagram of the electric field components (yoz profile) at the active device in this embodiment, where the electric field intensity is represented by color. The direction of the guided wave and the orientation of the active device are shown in the figure as the x-direction. Observing and comparing the x-component and z-component of the electric field, it can be seen that the x-component of the electric field at the active device is much larger than the z-component.

[0066] Figure 9 This is a diagram of the electric field components (xoz profile) at the active device in this embodiment, where the electric field intensity is represented by color. The x-direction is the direction of the guided wave and the orientation of the active device. The z-component at the edge of the microstrip line and the average field intensity at the active device are marked in the diagram.

[0067] Figure 6 , Figure 7 , Figure 8 , Figure 9 This demonstrates that in the region surrounding the active device, the electric field is primarily confined along the z-direction to the dielectric region between the microstrip line and the ground plane, consistent with the distribution of guided waves on the microstrip line. Only a small amount of electromagnetic waves propagate along the x-direction, generating a potential difference on the active device. This also verifies the phase modulation principle of the phase modulation circuit, namely, total internal reflection occurs at the active device, and phase control is achieved by adjusting the impedance of the active device.

[0068] Since the energy of the guided wave originates from the free-space electromagnetic waves input to the system, and this energy primarily resides in the dielectric region between the microstrip line and the ground plane, the electric field strength at the center of the active device is only 13% of that at the edge of the microstrip line. Therefore, only a small portion of the input energy generates a potential difference at the active device. For the same voltage withstand parameters of the active device, this embodiment can accommodate a larger power capacity.

[0069] In summary, this embodiment can achieve phase modulation function that meets actual needs, and can achieve a greater input power capacity than traditional methods, thus it can be widely used in high-power scenarios.

[0070] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A high-power phase-reconfigurable smart reflective surface, characterized in that, Composed of array elements with the same structure; The array element includes a receiving / transmitting unit (1), a coupling structure (2), and a phase modulation circuit (3), which are arranged in sequence to form a stacked structure. The receiving / transmitting unit (1) is used to convert electromagnetic waves in free space into distributed electric fields, and to convert the phase-modulated electric field converted by the coupling structure (2) into electromagnetic waves in free space and radiate them; the coupling structure (2) is used to convert the electric field on the receiving / transmitting unit (1) into a guided wave and transmit it to the phase modulation circuit (3), and to convert the phase-modulated guided wave from the phase modulation circuit (3) into a field on the receiving / transmitting unit (1); the phase modulation circuit (3) is composed of several microstrip lines and active devices, and is used to add an extra phase to the input guided wave and output it. The magnitude of the added extra phase is controlled by the applied DC voltage. The array element performs phase control on the incident wave under the applied voltage. The coupling structure (2) is used to convert the electric field on the receiving / transmitting unit (1) into a guided wave, and the phase modulation function is realized by the phase modulation circuit (3). Each part of the phase modulation circuit (3) consists of two varactor diodes and a microstrip line. The two varactor diodes are connected in parallel through a microstrip line with a wavelength of quartile. This is used to adjust the equivalent capacitance of the varactor diode by adjusting the reverse bias voltage applied to the varactor diode by the DC bias line, thereby adjusting the additional phase of the phase modulation circuit (3). The active device of the phase modulation circuit (3) is parallel to the direction of the guided wave, while the electric field of the guided wave is confined in the dielectric between the microstrip line and the dielectric substrate. Part of the electric field passes through the active device and forms a potential difference across the active device through induction. The guided wave propagating on the microstrip line is similar to a transverse electromagnetic wave. The electric and magnetic fields of the guided wave are approximately perpendicular to the direction of propagation, while the active device is parallel to the direction of propagation of the guided wave. When a guided wave propagates along a microstrip line, most of the electric field is confined in the medium between the microstrip line and the ground plane, while a small portion of the electric field is parallel to the propagation direction. When an active device propagates along the direction of the guided wave, a small portion of the electric field induces a potential difference across the active device.

2. The high-power phase-reconfigurable smart reflective surface according to claim 1, characterized in that, The coupling structure (2) is in the form of a via, probe, or slit.

3. The high-power phase-reconfigurable smart reflective surface according to claim 1, characterized in that, The receiving / transmitting unit (1) includes a top-layer patch and dielectric, and a ground plane, which are arranged in sequence to form a microstrip antenna.

4. A high-power phase-reconfigurable smart reflective surface according to claim 1, characterized in that, The array elements are arranged in a pre-designed shape, which can be a uniformly distributed rectangular array, circular array, hexagonal array, octagonal array, or a randomly distributed array.

5. The high-power phase-reconfigurable smart reflective surface according to claim 1, characterized in that, The active device acts as a pure reactance, and its guided wave propagates along the microstrip line, interacting with the active device to achieve phase modulation.

6. A high-power phase-reconfigurable smart reflective surface according to claim 1, characterized in that, The active device of the phase modulation circuit (3) is electrically connected by a metal wire and is used to apply a DC bias voltage. The phase modulation circuit (3) is used to change the terminal impedance to add different additional phases to the reflected wave of the guided wave when a DC voltage is applied.

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