Multi-bit terahertz phased array antenna with zero direct current power consumption

Abstract

The application provides a multi-bit terahertz phased array antenna with zero DC power consumption, and relates to the technical field of phased array antennas.The antenna comprises a dielectric substrate, basic radiation units, memory metal units and a control unit.The basic radiation units are arranged on a radiation layer of the dielectric substrate, and each basic radiation unit is associated with a plurality of memory metal units based on the number of bits.The control unit is arranged in the dielectric substrate or above the memory metal units, and is used for applying a transient excitation to one or more memory metal units associated with the basic radiation units when the basic radiation units need to switch the phase state.The memory metal units are deformed after being subjected to the transient excitation, and maintain the deformed state until the next transient excitation is applied.The application adopts the memory metal units as phase state storage elements, and only needs to apply a transient excitation when the phase state is switched.The memory metal units are uniformly controlled by the control unit, and the control design complexity is reduced.

Description

Technical Field

[0001] This invention relates to the field of phased array antenna technology, and in particular to a multi-bit terahertz phased array antenna with zero DC power consumption. Background Technology

[0002] Terahertz phased array antennas are core modules for realizing high-speed wireless communication, high-resolution imaging, and precision sensing. Currently, there are two main types of terahertz phased arrays: one is a chip-based active phased array based on compound semiconductor or silicon-based processes, and the other is a phased array based on programmable metasurfaces or reflective smart surfaces.

[0003] Chip-based active phased arrays primarily employ gallium arsenide, gallium nitride, or silicon-based processes to integrate the transmit / receive modules and phase shifters within a single chip. By integrating multiple digital phase shifters on the chip, the phase of the radio frequency signal is precisely controlled. Each antenna element or subarray is connected to active circuitry at its rear end, typically requiring a high DC bias voltage and a large quiescent current to drive the amplifiers and phase shifters.

[0004] Metasurface or smart surface phased arrays alter the phase of reflected or transmitted waves by adjusting the electromagnetic properties of the unit surface. Specifically, PIN diodes or HEMT switches are integrated into the resonant structure of the unit using micro-nano technology, and the state of the switches is controlled by a DC feeder, causing the unit to exhibit different phase responses, thus decoupling the RF front-end from the phase control. Compared to chip-based active phased arrays, this reduces costs; however, as the number of bits increases, the complexity of the DC control design also increases, resulting in higher control complexity.

[0005] Therefore, it is necessary to provide a phased array antenna that can reduce DC power consumption and multi-bit DC control complexity. Summary of the Invention

[0006] This invention provides a zero-DC power consumption multi-bit terahertz phased array antenna, which can reduce DC power consumption and multi-bit DC control complexity.

[0007] This invention provides a zero-DC-power multi-bit terahertz phased array antenna, comprising a dielectric substrate, a basic radiating element, a memory metal element, and a control unit. The basic radiating element is disposed on the radiating layer of the dielectric substrate, and each basic radiating element is associated with multiple memory metal elements based on the number of bits. The control unit is disposed within the dielectric substrate or above the memory metal elements and is used to apply instantaneous excitation to one or more memory metal elements associated with the basic radiating element when the basic radiating element needs to switch phase states. The memory metal elements deform after being instantaneously excited and maintain the deformed state until they are subjected to the next instantaneous excitation.

[0008] According to the present invention, a zero-DC power consumption multi-bit terahertz phased array antenna is provided, wherein the basic radiating element includes a circular radiator, and a plurality of memory metal units are integrated at the opening of the circular radiator, the coupling gap or the feed point. The circular radiator has a plurality of preset contact points distributed at 45° intervals along the circumference of the circular radiator. The anchor end of each memory metal unit is disposed on the dielectric substrate. The free end of each memory metal unit is initially connected to the contact point, and disconnected from the contact point after being subjected to instantaneous excitation.

[0009] According to the present invention, a zero DC power consumption multi-bit terahertz phased array antenna is provided, wherein the number of bits is two, and four memory metal units are integrated at the opening of the ring, the coupling gap or the feed point of the ring radiator. The ring radiator has four preset contact points distributed at 45° intervals along the circumference of the ring. When the free end of any memory metal unit is connected to the contact point, it is in a conducting state; otherwise, it is in a cut-off state.

[0010] According to the present invention, a zero-DC power consumption multi-bit terahertz phased array antenna is provided, wherein the four memory metal elements are sequentially designated as a first memory metal element, a second memory metal element, a third memory metal element, and a fourth memory metal element. When only the first memory metal element is in the conducting state, the response phase of the ring radiator is 0°; when only the second memory metal element is in the conducting state, the response phase of the ring radiator is 90°; when only the third memory metal element is in the conducting state, the response phase of the ring radiator is 180°; and when only the fourth memory metal element is in the conducting state, the response phase of the ring radiator is 270°.

[0011] According to the present invention, a zero DC power consumption multi-bit terahertz phased array antenna is provided, wherein the geometric dimensions of the ring radiator are determined based on the terahertz frequency band.

[0012] According to the present invention, a zero DC power consumption multi-bit terahertz phased array antenna is provided, wherein the free end of the memory metal element forms a metal-metal direct contact with the contact point in the conducting state.

[0013] According to the present invention, a zero-DC power consumption multi-bit terahertz phased array antenna is provided, wherein the dielectric substrate includes a radiating layer, an isolation layer and a control layer disposed from top to bottom. The radiating layer is used to radiate electromagnetic waves, the control layer is used to control the realization of photothermal conversion, and the isolation layer is used to isolate thermal coupling between different basic radiating units. The control layer is provided with a micro heater to form a thermal control path, or the radiating layer is provided with a wave-transparent photothermal conversion film to form a thermal control path.

[0014] According to the present invention, a zero DC power consumption multi-bit terahertz phased array antenna is provided, wherein the isolation layer includes a thermal resistance groove, which is an air gap etched on the isolation layer of a dielectric substrate, the depth of which penetrates the isolation layer, and the width is less than 1 / 10 of the unit spacing.

[0015] According to the present invention, a zero DC power consumption multi-bit terahertz phased array antenna is provided, wherein the radiating layer is further used to form a radio frequency signal transmission path with the basic radiating element, and the radio frequency signal transmission path and the thermal control path are independent of each other in physical structure and spatial layout.

[0016] According to the present invention, a zero DC power consumption multi-bit terahertz phased array antenna is provided, wherein the control unit is disposed above the memory metal unit and includes a laser array, the surface of the memory metal unit is provided with a photothermal conversion layer, the control unit emits laser to one or more memory metal units associated with the basic radiating unit, and the photothermal conversion layer on the surface of the memory metal unit converts the laser into heat.

[0017] The present invention provides a zero-DC-power multi-bit terahertz phased array antenna, comprising a dielectric substrate, basic radiating elements, shape memory metal elements, and a control unit. The basic radiating elements are disposed on the radiating layer of the dielectric substrate, and each basic radiating element is associated with multiple shape memory metal elements based on the number of bits. The control unit is disposed within the dielectric substrate or above the shape memory metal elements and is used to apply instantaneous excitation to one or more shape memory metal elements associated with the basic radiating element when the basic radiating element needs to switch phase states. The shape memory element deforms upon receiving the instantaneous excitation and maintains the deformed state until it receives the next instantaneous excitation. Since shape memory metals have a shape memory effect after phase transitions, the present invention uses shape memory metal elements as phase state sealing elements. After the state switch is completed, it can maintain the on or off state without continuous power supply. Therefore, only instantaneous excitation needs to be applied during phase state switching. The phased array antenna does not consume DC power during beam pointing lock, achieving zero DC-power consumption. As the number of bits increases, the present invention only needs to add shape memory metal elements associated with the basic radiating elements. The shape memory metal elements can be uniformly controlled by the control unit, reducing the complexity of DC control design. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1This is a schematic diagram of the structure of the zero DC power consumption multi-bit terahertz phased array antenna provided by the present invention.

[0020] Figure 2 This is a schematic cross-sectional view of the dielectric substrate provided by the present invention.

[0021] Figure 3 This is one of the flowcharts illustrating the zero DC power consumption multi-bit terahertz phased array antenna control method provided by the present invention.

[0022] Figure 4 This is the second flowchart illustrating the zero DC power consumption multi-bit terahertz phased array antenna control method provided by the present invention.

[0023] Figure 5 This is a schematic diagram of the unit reflection coefficient when the incident wave is left-handed circularly polarized, provided by the present invention.

[0024] Figure 6 This is a schematic diagram of the compensation phase distribution required for the array when the scanning angle is 0°, provided by the present invention.

[0025] Figure 7 This is a schematic diagram of the antenna radiation characteristics when the incident wave is left-handed circularly polarized and the scanning angle is 0°.

[0026] In the figure, 1-dielectric substrate, 2-basic radiating unit, 3-radiating layer, 4-isolation layer, 5-control layer, 6-thermal resistance trench. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0028] Figure 1 This is a schematic diagram of the zero DC power consumption multi-bit terahertz phased array antenna provided by the present invention, as shown below. Figure 1As shown, the present invention provides a zero DC power consumption multi-bit terahertz phased array antenna, including a dielectric substrate 1, a basic radiating element 2, a memory metal element, and a control unit. The basic radiating element 2 is disposed on the radiating layer 3 of the dielectric substrate 1, and each basic radiating element 2 is associated with multiple memory metal elements based on the number of bits. The control unit is disposed within the dielectric substrate 1 or above the memory metal elements, and is used to apply instantaneous excitation to one or more memory metal elements associated with the basic radiating element 2 when the basic radiating element 2 needs to switch phase states. The memory metal elements deform after being subjected to instantaneous excitation and maintain the deformed state until they are subjected to the next instantaneous excitation.

[0029] Multiple basic radiating units 2 are provided on the dielectric substrate 1. These basic radiating units 2 are arranged periodically to form a two-dimensional phased array. The spacing between the basic radiating units 2 is determined according to the operating frequency and is set to 0.6 operating wavelengths. Thermal resistance control is achieved through the gaps between the basic radiating units 2. The number of memory metal units associated with each basic radiating unit 2 is related to the number of bits. For example, two bits correspond to 4 memory metal units, and three bits correspond to 8 memory metal units.

[0030] In its initial state, the shape memory metal cell is connected to the basic radiating unit 2 and is in a conductive state. Upon instantaneous excitation, the shape memory metal cell deforms, disconnecting from the basic radiating unit 2 and entering a cutoff state. The combination of cutoff / conduction states of the shape memory metal cells associated with the basic radiating unit 2 corresponds to the phase response of the basic radiating unit 2.

[0031] Phase state switching in a terahertz phased array antenna refers to the process of changing the direction or shape of the synthesized beam in space by altering the phase difference of the excitation signals of each basic radiating element 2. In traditional electronic control schemes, phase state switching is achieved by the phase shifter at the back end of each element loading different control signals in real time according to the beam control algorithm, reconfiguring the relative phase between elements according to a preset step, thereby satisfying the coherent constructive condition in a specific direction in the far field and causing destructive phases in other directions, realizing rapid beam transitions or continuous scanning without mechanical rotation. However, the phase shifter continuously consumes DC power. Even when there is no RF signal output or it is in standby mode, the active devices inside the phase shifter must still be biased in the on state to maintain rapid phase state switching, resulting in high static power consumption. As the array size increases, the heat flux density inside the phase shifter increases dramatically. In the terahertz band, due to the sub-millimeter spacing between elements, the heat dissipation space is extremely limited. The temperature rise caused by high power consumption not only deteriorates the noise figure of the device but may also lead to phase shift drift and array performance failure, limiting the integration scale and practical application scenarios of terahertz phased array antennas. To address this, this invention utilizes the property of shape memory metals to deform above the phase transition temperature and retain that deformation after cooling. The shape memory metal elements are used as non-volatile latching elements for the phase state. By applying a short-term thermal excitation to the shape memory metal sheet, mechanical displacement is generated, thereby changing the connection state of the radio frequency path.

[0032] It is understood that this invention uses memory metal units as phase state sealing elements. After the state switching is completed, it can maintain the on or off state without continuous power supply. Therefore, only a momentary excitation is applied during phase state switching. The phased array antenna does not consume DC power during beam pointing lock, achieving zero DC power consumption. As the number of bits increases, this invention only requires adding memory metal units associated with the basic radiating unit 2. The memory metal units can be uniformly controlled by the control unit, reducing the complexity of DC control design. This invention eliminates the static power consumption of traditional active phased arrays and PIN diode metasurfaces, making standby power consumption close to zero, improving energy utilization efficiency, and is especially suitable for energy-constrained portable devices, satellite payloads, and long-endurance unmanned platforms.

[0033] As an optional embodiment, the basic radiating unit 2 includes a circular radiator. The circular radiator integrates multiple memory metal units at the opening of the circular ring, the coupling gap, or the feed point. The circular radiator has multiple preset contact points distributed at 45° intervals along the circumference of the ring. The anchor end of each memory metal unit is located on the dielectric substrate 1. The free end of each memory metal unit is initially connected to the contact point, and disconnected from the contact point after being subjected to instantaneous excitation.

[0034] Optionally, the number of bits is two, and the annular radiator integrates four memory metal units at the opening of the annular ring, the coupling gap, or the feed point. The annular radiator has four preset contact points distributed every 45° along the circumference of the annular ring. When the free end of any memory metal unit is connected to the contact point, it is in a conducting state; otherwise, it is in a cut-off state.

[0035] Optionally, the geometry of the annular radiator is determined based on the terahertz frequency band.

[0036] Optionally, the dielectric substrate 1 is made of low-loss quartz terahertz dielectric material, and the dielectric substrate 1 can be divided into a radiation layer 3, an isolation layer 4 and a control layer 5 from top to bottom.

[0037] A ring-shaped radiator is disposed on the radiating layer 3 of the dielectric substrate 1 and is made of metal, preferably gold. The ring-shaped radiator is open and its geometric dimensions are determined according to the operating terahertz frequency band. The average circumference of the ring-shaped radiator is approximately one operating wavelength.

[0038] The annular radiator has four preset contact points for forming an electrical connection with the memory metal unit. The four contact points are spaced 45 degrees apart along the circumference of the annular ring.

[0039] The shape memory metal unit is made of an alloy material with a unidirectional shape memory effect. Each shape memory metal unit has a fixed anchor end and a free end. The anchor end is fixed on the dielectric substrate 1, and the free end is in contact with the contact point on the annular radiator at room temperature. After being heated to the phase transition temperature, it deforms and moves to the position where it separates from the contact point. The phase transition temperature can be 60-100℃. After cooling, the shape memory metal unit retains the deformed state until the next heating excitation.

[0040] The four shape memory metal units correspond to the four contact points on the annular radiator, and each is controlled independently. By controlling the conduction or cutoff of each shape memory metal unit, the equivalent boundary conditions and current path distribution of the annular radiator can be changed.

[0041] The shape memory metal unit is made of bidirectional shape memory alloy and has two stable mechanical states: a room temperature state and a phase transition state. In the room temperature state, the free end is connected to the contact point, and the shape memory metal unit is in a conductive state. In the phase transition state, the free end deforms under excitation and separates from the contact point, and the shape memory metal unit is in a cut-off state. When it is necessary to restore the conduction of the shape memory metal unit in the cut-off state, the control unit applies a short-term thermal excitation again, causing the shape memory metal unit to undergo a reverse phase transition, and the free end returns to the position in contact with the contact point. Both the room temperature state and the phase transition state can be maintained for a long time without continuous power supply.

[0042] When the free end of the shape memory metal unit is in the conductive state, it forms a direct metal-metal contact with the contact point.

[0043] The control layer 5 only operates during state switching and stops excitation immediately after the switching is completed. The entire array is in a zero DC power consumption state during the beam hold phase.

[0044] It is understood that this invention uses a circular ring antenna as the basic radiating unit 2, and integrates four memory metal units in each unit as non-volatile latching elements for the phase state; by controlling the contact and separation of the memory metal units and the radio frequency structure through thermal deformation, four different current path distributions are achieved, thereby obtaining a 2-bit phase quantization state; after the state switching is completed, the memory metal units maintain the current shape by relying on their shape memory effect, and can lock the phase state without any continuous power supply, achieving zero DC power consumption operation; at the same time, the radio frequency path and the thermal control path are physically separated, avoiding the parasitic influence of the traditional DC bias network on the terahertz radiation performance, and ensuring high-efficiency electromagnetic radiation.

[0045] As an optional embodiment, the four memory metal units are sequentially designated as a first memory metal unit, a second memory metal unit, a third memory metal unit, and a fourth memory metal unit. When only the first memory metal unit is in the conducting state, the response phase of the annular radiator is 0°; when only the second memory metal unit is in the conducting state, the response phase of the annular radiator is 90°; when only the third memory metal unit is in the conducting state, the response phase of the annular radiator is 180°; and when only the fourth memory metal unit is in the conducting state, the response phase of the annular radiator is 270°.

[0046] The on / off states of the four memory metal plates constitute a 4-bit binary code, but through the symmetrical design of the circular ring cell, only four states correspond to four different phase responses. The encoding is shown in the table below:

[0047] In the table above, metal sheet 1 is the first memory metal unit, metal sheet 2 is the second memory metal unit, metal sheet 3 is the third memory metal unit, and metal sheet 4 is the fourth memory metal unit. By combining these four states, 2-bit phase quantization is achieved with a phase step of 90°. In practical designs, the four phase states can be optimized by adjusting the contact position of the memory metal sheets, the size of the ring, and the position of the power supply point, so that the phase difference is precisely matched to 90°.

[0048] Understandably, this invention employs a circular ring cell structure, integrating four memory metal sheets into the key radiating gaps or coupling structures of the cell. The on / off control of the RF signal is achieved through the physical contact of the memory metal sheets, rather than through the junction capacitance or channel conduction of semiconductor devices. This pure metal contact method provides extremely low contact resistance in the on-state and excellent physical isolation in the off-state, thus avoiding the parasitic parameters and insertion losses present in PIN diodes or FET switches in the terahertz band. Simultaneously, since a complex DC bias line network is unnecessary, parasitic coupling between the bias line and the radiating structure is eliminated, further reducing system losses and achieving high-efficiency terahertz radiation. Furthermore, this invention achieves four distinguishable phase states on the circular ring cell through the symmetrical combination of the four memory metal sheets, completing 2-bit phase quantization. Compared to a 1-bit phased array, this effectively suppresses quantization sidelobes, improving beam pointing accuracy and gain; compared to active phase shifters with higher bit counts, it avoids the cumulative insertion loss caused by multiple series-connected phase shifting units, achieving an excellent balance between efficiency and accuracy.

[0049] Figure 2 This is a schematic cross-sectional view of the dielectric substrate 1 provided by the invention, as shown in the figure. Figure 2 As shown, in an optional embodiment, the dielectric substrate 1 includes a radiation layer 3, an isolation layer 4, and a control layer 5 disposed from top to bottom. The radiation layer 3 is used to radiate electromagnetic waves, the control layer 5 is used to control and realize photothermal conversion, and the isolation layer 4 is used to isolate thermal coupling between different basic radiation units 2. The control layer 5 is provided with a micro heater to form a thermal control path, or the radiation layer 3 is provided with a wave-transparent photothermal conversion film to form a thermal control path control layer 5 radiation layer 3.

[0050] Optionally, the isolation layer 4 includes a thermal resistance groove 6, which is an air gap etched on the isolation layer 4 of the dielectric substrate 1. The depth of the thermal resistance groove 6 penetrates the isolation layer 4, and the width is less than 1 / 10 of the cell spacing. The thermal resistance groove 6 can effectively block the heat conduction path between adjacent cells, reduce the probability of thermal crosstalk to below 5%, and ensure that the phase stability of surrounding cells is not affected when a single cell switches states.

[0051] Optionally, the radiating layer 3 is also used to form a radio frequency signal transmission path with the basic radiating unit 2, and the radio frequency signal transmission path is independent of the thermal control path in terms of physical structure and spatial layout.

[0052] In another alternative embodiment, the control unit is disposed above the memory metal unit and includes a laser array. The surface of the memory metal unit is provided with a photothermal conversion layer. The control unit emits lasers to one or more memory metal units associated with the basic radiation unit 2, and the photothermal conversion layer on the surface of the memory metal unit converts the lasers into heat.

[0053] Optionally, to prevent thermal crosstalk between adjacent units, a thermal isolation structure is provided at the unit boundary. The thermal isolation structure can be formed by etching thermal resistance grooves 6 on the dielectric substrate 1 to create an air gap.

[0054] In this embodiment of the invention, instead of an integrated heater, a light-absorbing material is coated onto the surface of the shape memory metal sheet. An infrared laser diode array is positioned above the array, and the irradiation position of the laser beam is controlled by a spatial light modulator. When a state switch is required for a particular unit, the laser beam irradiates the shape memory metal sheet area of ​​that unit, converting light energy into heat energy, causing the shape memory metal sheet to heat up and deform. This solution achieves completely non-contact phase control, further simplifying the electrical connections of the array, and is particularly suitable for applications requiring completely metal-free control lines.

[0055] It is understood that the embodiments of the present invention employ thermal excitation methods such as integrated microheaters, photothermal conversion, or external infrared radiation to drive the memory metal sheet. The thermal control path and the RF signal transmission path are independent of each other in physical structure and spatial layout, avoiding the parasitic influence of the DC bias network on RF performance in traditional phased arrays, while ensuring the reliability of state switching. In the conducting state, the memory metal sheet directly forms a metal-metal contact with the RF structure, replacing the PN junction or channel of traditional semiconductor switches, achieving extremely low insertion loss and high linearity in the terahertz band. To ensure that no thermal crosstalk occurs between adjacent basic radiating units 2 during state switching, the unit structure design employs thermal isolation structures such as thermal resistance grooves 6 and low thermal conductivity dielectric filling. After switching, the microstructure is used for rapid heat dissipation, allowing the memory metal sheet to quickly return to ambient temperature and ensuring state stability.

[0056] In summary, this invention achieves phase state locking and maintenance without consuming any DC power through a non-volatile control mechanism based on thermally induced phase change materials. Excitation is applied only during state switching, thus completely eliminating the static power consumption required to maintain beam pointing and achieving zero DC power consumption operation. This solves the problem of continuous DC power consumption in existing active chip-type phased arrays when maintaining beam pointing. This invention employs a circular ring unit structure and integrates a memory metal sheet as a phase control element within the unit. It directly controls RF on / off via thermal conduction rather than electrical signals, significantly simplifying or eliminating the DC bias network coupled to the RF path, reducing additional losses introduced by the control circuit, improving the overall array efficiency, and solving the problem of mutual coupling between the DC bias network and the RF structure in existing terahertz phased arrays. The invention addresses the issue of introducing additional losses. In the on-state, the RF signal path only passes through the metal contact surface, avoiding the on-resistance and nonlinear losses of the semiconductor junction. This achieves 2-bit phase quantization while maintaining low insertion loss and high radiation efficiency, resolving the contradiction between high efficiency and low quantization sidelobes in existing 2-bit phased arrays. Furthermore, the invention uses a memory metal sheet as the phase control element. State switching relies only on localized, short-term thermal excitation, eliminating the need for continuous power dissipation during state holding. Therefore, the overall heat dissipation of the array is extremely low, reducing the requirements for heat dissipation structures. Simultaneously, the memory metal sheet exhibits purely mechanical contact or detachment during state holding, independent of continuous bias voltage, resulting in high reliability and radiation resistance, making it particularly suitable for space applications and extreme environments.

[0057] The following describes the zero-DC power consumption multi-bit terahertz phased array antenna control method provided by the present invention. The zero-DC power consumption multi-bit terahertz phased array antenna control method described below can be referred to in correspondence with the zero-DC power consumption multi-bit terahertz phased array antenna described above.

[0058] Figure 3 This is one of the flowcharts illustrating the zero-DC-power multi-bit terahertz phased array antenna control method provided by the present invention, such as... Figure 3 As shown, the present invention also provides a zero DC power consumption multi-bit terahertz phased array antenna control method for controlling the zero DC power consumption multi-bit terahertz phased array antenna described in any of the above embodiments. The method includes steps S310-S330.

[0059] Step S310: Based on the target beam direction, determine the target phase state required for each of the basic radiating elements.

[0060] Step S320: Based on the target phase state, determine the excitation signal corresponding to the memory metal unit associated with each of the basic radiating units.

[0061] Step S330: Based on the excitation signal, control unit is controlled to apply instantaneous excitation to one or more memory metal units associated with the basic radiation unit.

[0062] Specifically, based on the target beam direction, the state code required for each basic radiation unit is calculated, the control signal corresponding to the state code is converted into the excitation signal of the thermal control layer of each unit, and the state of each unit is switched sequentially or in parallel to ensure that no thermal interference is generated to adjacent units during the switching process.

[0063] When switching beam states, the control units of the target basic radiating elements are activated sequentially or in groups, and a short thermal pulse is applied to the corresponding memory metal elements to deform them to the target state. After the switching is completed, all control units are powered off, and the entire basic radiating element array enters the zero DC power consumption maintenance mode. When the beam direction changes again, the control units are activated again for reconfiguration.

[0064] Figure 4 This is the second flowchart illustrating the zero-DC power consumption multi-bit terahertz phased array antenna control method provided by this invention, as shown below. Figure 4 As shown, in another embodiment, the zero DC power consumption multi-bit terahertz phased array antenna control method provided by the present invention includes steps S410-S450.

[0065] Step S410, Initialization: Apply uniform thermal excitation to all memory metal sheets to bring them into the initial state. For example, set the initial state to be completely cut off. At this time, the ring radiator is in a complete ring state with a phase of 0°.

[0066] Step S420, State Configuration: Based on the target beam direction, calculate the 2-bit phase state required for each basic radiating unit, generate the corresponding memory metal sheet combination code, activate the control layer of each unit in sequence, and apply a short thermal pulse only to the memory metal sheet that needs to change its state, so that it deforms to the target position.

[0067] Step S430, Zero Power Consistency: After state configuration is complete, power supply to all thermal control layers is stopped. The shape memory metal sheet is mechanically locked in its current state by the shape memory effect, maintaining its phase state without any continuous energy input. During beam pointing maintenance, the entire array does not consume any DC power, except for possible monitoring circuitry.

[0068] Step S440, Beam Reconfiguration: When it is necessary to change the beam direction, repeat the state configuration and re-thermally excite the basic radiating element whose state needs to be changed. During the configuration process, only a short-duration, low-energy thermal pulse is required, and the overall average power consumption is extremely low.

[0069] Step S450, Radiation and Reception: During the state holding period, the radio frequency signal is input through the feeding structure and radiated out through the annular radiator. Because the shape memory metal sheet forms a direct metal-metal contact in the conducting state, the insertion loss is much lower than that of a semiconductor switch; at the same time, without the parasitic losses introduced by the DC bias network, the radiation efficiency is significantly improved.

[0070] As one embodiment, a zero-DC-power multi-bit terahertz phased array antenna includes a dielectric substrate, a basic radiating element, a memory metal element, and a control unit. The basic radiating element is disposed on the radiating layer of the dielectric substrate, and each basic radiating element is associated with multiple memory metal elements based on the number of bits. The control unit is disposed within the dielectric substrate or above the memory metal elements and is used to apply instantaneous excitation to one or more memory metal elements associated with the basic radiating element when the basic radiating element needs to switch phase states. The memory metal elements deform after being instantaneously excited and maintain the deformed state until they are subjected to the next instantaneous excitation.

[0071] As an example, the basic radiating unit includes a circular radiator. Multiple memory metal units are integrated in the circular radiator at the opening of the ring, the coupling gap, or the feed point. Multiple preset contact points are distributed at 45° intervals along the circumference of the ring. The anchor end of each memory metal unit is located on the dielectric substrate. The free end of each memory metal unit is initially connected to the contact point, and disconnected from the contact point after being subjected to instantaneous excitation.

[0072] As an example, the number of bits is two. The annular radiator integrates four memory metal units at the opening of the annular ring, the coupling gap, or the feed point. The annular radiator has four preset contact points distributed every 45° along the circumference of the annular ring. When the free end of any memory metal unit is connected to the contact point, it is in a conductive state; otherwise, it is in a cut-off state.

[0073] As one embodiment, the four memory metal units are sequentially designated as a first memory metal unit, a second memory metal unit, a third memory metal unit, and a fourth memory metal unit. When only the first memory metal unit is in the conducting state, the response phase of the ring radiator is 0°; when only the second memory metal unit is in the conducting state, the response phase of the ring radiator is 90°; when only the third memory metal unit is in the conducting state, the response phase of the ring radiator is 180°; and when only the fourth memory metal unit is in the conducting state, the response phase of the ring radiator is 270°.

[0074] As one example, the geometry of the annular radiator is determined based on the terahertz frequency band.

[0075] As an example, the free end of the shape memory metal unit forms a direct metal-metal contact with the contact point when it is in the conductive state.

[0076] As one embodiment, the dielectric substrate includes a radiation layer, an isolation layer, and a control layer disposed from top to bottom. The radiation layer is used to radiate electromagnetic waves, the control layer is used to control the realization of photothermal conversion, and the isolation layer is used to isolate thermal coupling between different basic radiation units. The control layer is provided with a micro heater to form a thermal control path, or the radiation layer is provided with a wave-transparent photothermal conversion film to form a thermal control path.

[0077] As one embodiment, the isolation layer includes a thermal resistance trench, which is an air gap etched on the isolation layer of the dielectric substrate, with a depth penetrating the isolation layer and a width less than 1 / 10 of the cell pitch.

[0078] As an example, the radiating layer is also used to form a radio frequency signal transmission path with the basic radiating unit, and the radio frequency signal transmission path is independent of the thermal control path in terms of physical structure and spatial layout.

[0079] As one embodiment, the control unit is located above the memory metal unit and includes a laser array. The surface of the memory metal unit is provided with a photothermal conversion layer. The control unit emits laser light to one or more memory metal units associated with the basic radiation unit, and the photothermal conversion layer on the surface of the memory metal unit converts the laser light into heat.

[0080] It should be noted that the zero DC power consumption multi-bit terahertz phased array antenna control method provided by this invention has the same technical effects as the zero DC power consumption multi-bit terahertz phased array antenna, which will not be elaborated further.

[0081] The radio frequency module provided by the present invention is described below. The radio frequency module described below can be referred to in correspondence with the zero DC power consumption multi-bit terahertz phased array antenna described above.

[0082] The present invention also provides a radio frequency module, including any one of the zero DC power consumption multi-bit terahertz phased array antennas described in any one of the claims.

[0083] As one embodiment, a zero-DC-power multi-bit terahertz phased array antenna includes a dielectric substrate, a basic radiating element, a memory metal element, and a control unit. The basic radiating element is disposed on the radiating layer of the dielectric substrate, and each basic radiating element is associated with multiple memory metal elements based on the number of bits. The control unit is disposed within the dielectric substrate or above the memory metal elements and is used to apply instantaneous excitation to one or more memory metal elements associated with the basic radiating element when the basic radiating element needs to switch phase states. The memory metal elements deform after being instantaneously excited and maintain the deformed state until they are subjected to the next instantaneous excitation.

[0084] As an example, the basic radiating unit includes a circular radiator. Multiple memory metal units are integrated in the circular radiator at the opening of the ring, the coupling gap, or the feed point. Multiple preset contact points are distributed at 45° intervals along the circumference of the ring. The anchor end of each memory metal unit is located on the dielectric substrate. The free end of each memory metal unit is initially connected to the contact point, and disconnected from the contact point after being subjected to instantaneous excitation.

[0085] As an example, the number of bits is two. The annular radiator integrates four memory metal units at the opening of the annular ring, the coupling gap, or the feed point. The annular radiator has four preset contact points distributed every 45° along the circumference of the annular ring. When the free end of any memory metal unit is connected to the contact point, it is in a conductive state; otherwise, it is in a cut-off state.

[0086] As one embodiment, the four memory metal units are sequentially designated as a first memory metal unit, a second memory metal unit, a third memory metal unit, and a fourth memory metal unit. When only the first memory metal unit is in the conducting state, the response phase of the ring radiator is 0°; when only the second memory metal unit is in the conducting state, the response phase of the ring radiator is 90°; when only the third memory metal unit is in the conducting state, the response phase of the ring radiator is 180°; and when only the fourth memory metal unit is in the conducting state, the response phase of the ring radiator is 270°.

[0087] As one example, the geometry of the annular radiator is determined based on the terahertz frequency band.

[0088] As an example, the free end of the shape memory metal unit forms a direct metal-to-metal contact with the contact point when it is in a conductive state.

[0089] As one embodiment, the dielectric substrate includes a radiation layer, an isolation layer, and a control layer disposed from top to bottom. The radiation layer is used to radiate electromagnetic waves, the control layer is used to control the realization of photothermal conversion, and the isolation layer is used to isolate thermal coupling between different basic radiation units. The control layer is provided with a micro heater to form a thermal control path, or the radiation layer is provided with a wave-transparent photothermal conversion film to form a thermal control path.

[0090] As one embodiment, the isolation layer includes a thermal resistance trench, which is an air gap etched on the isolation layer of the dielectric substrate, with a depth penetrating the isolation layer and a width less than 1 / 10 of the cell pitch.

[0091] As an example, the radiating layer is also used to form a radio frequency signal transmission path with the basic radiating unit, and the radio frequency signal transmission path is independent of the thermal control path in terms of physical structure and spatial layout.

[0092] As an example, the radio frequency module provided by the present invention further includes a control system, which is used to determine the target phase state required for each of the basic radiating units based on the target beam pointing, determine the excitation signal corresponding to the memory metal unit associated with each of the basic radiating units based on the target phase state, and control the control unit to apply instantaneous excitation to one or more memory metal units associated with the basic radiating units based on the excitation signal.

[0093] Optionally, the control system includes a global controller, a state configuration circuit, and a timing control module.

[0094] A global controller is used to determine the target phase state required for each of the basic radiating elements based on the target beam pointing. A state configuration circuit is used to determine the excitation signal corresponding to the memory metal unit associated with each of the basic radiating units based on the target phase state. A timing control module is used to control the control unit to apply instantaneous excitation to one or more memory metal units associated with the basic radiating unit based on the excitation signal.

[0095] During beam state switching, the global controller sequentially or in groups activates the control units of the target basic radiating element, applying a short-duration thermal pulse to the corresponding shape memory metal element to deform it to the target state. After the switching is complete, all control units are powered off, and the entire basic radiating element array enters a zero DC power consumption hold-up mode. When the beam pointing changes again, the control units are reactivated for reconfiguration.

[0096] The working principle of the radio frequency module provided by this invention includes initialization, state configuration, zero power consumption maintenance, beam reconstruction, radiation and reception.

[0097] Initialization: Apply a uniform thermal excitation to all memory metal sheets to bring them into the initial state. For example, set the initial state to be completely cut off. At this time, the ring radiator is in a complete ring state with a phase of 0°.

[0098] State configuration: Based on the target beam direction, calculate the 2-bit phase state required for each basic radiating element, generate the corresponding memory metal sheet combination code, activate the control layer of each element in sequence, and apply a short thermal pulse only to the memory metal sheet that needs to change state, so that it deforms to the target position.

[0099] Zero-power hold-up: Once the state configuration is complete, power to all thermal control layers is stopped. The shape memory metal sheet is mechanically locked in its current state by the shape memory effect, maintaining its phase state without any continuous energy input. During beam pointing hold-up, the entire array, except for possible monitoring circuitry, consumes no DC power from the RF phase control section.

[0100] Beam reconfiguration: When the beam direction needs to be changed, the state configuration is repeated, and the basic radiating elements that need to be changed are re-thermally excited and configured. During the configuration process, only short-duration, low-energy thermal pulses are required, and the overall average power consumption is extremely low.

[0101] Radiation and reception: During the state holding period, the radio frequency signal is input through the feed structure and radiated out through the annular radiator. Because the shape memory metal sheet forms a direct metal-metal contact in the conducting state, the insertion loss is much lower than that of a semiconductor switch; at the same time, the absence of parasitic losses introduced by the DC bias network significantly improves the radiation efficiency.

[0102] Figure 5 This is a schematic diagram of the unit reflection coefficient when the incident wave is left-handed circularly polarized, provided by the present invention. Figure 5 In the figure, (a) represents the reflection amplitude of the four main polarization states, (b) represents the reflection phase of the four main polarization states, (c) represents the reflection amplitude of the four cross-polarization states, and (d) represents the reflection phase of the four cross-polarization states. When the incident wave is set to left-hand circular polarization for element simulation, the main polarization refers to the reflection component with the same rotation direction as the incident wave. The smaller the reflection amplitude within the working frequency band, the better the element matching. The corresponding reflection phase reflects the time delay of the reflected wave relative to the incident wave, and usually a 180° jump occurs near the resonance point. Cross-polarization refers to the reflection component with the opposite rotation direction to the incident wave. The closer the reflection amplitude is to 1, the stronger the ability of the surface to reflect the circularly polarized wave in the opposite rotation direction. Conversely, the smaller the reflection amplitude, the higher the polarization purity. The reflection phase, in addition to including the path delay, also naturally includes the ±90° inherent phase difference brought by the orthogonal basis of circular polarization.

[0103] Figure 6 This is a schematic diagram of the compensation phase distribution required by the array when the scanning angle is 0°, as provided by the present invention. Figure 6As shown, when the scanning angle θ = 0°, the required compensation phase distribution is all zero, and the phase of the excitation current of each unit should be exactly the same. This is because the spatial phase delay caused by the plane wave incident or radiated from the normal direction reaching each unit is equal, and there is no path difference caused by oblique projection. Therefore, there is no need to apply any linear phase gradient for beam tilt compensation.

[0104] Figure 7 This is a schematic diagram of the antenna radiation characteristics when the incident wave is left-hand circularly polarized and the scanning angle is 0°. In the figure, (a) is the three-dimensional far-field radiation pattern at 220 GHz, and (b) is the two-dimensional far-field radiation pattern at 220 GHz. At the 220 GHz frequency point, since the array scanning angle is 0°, each basic radiating element only needs to provide equal-phase excitation, so that the radiated energy is superimposed in phase in the main radiation direction. The LHCP component represented by the red line has a significant radiation main lobe in the 0° direction, and the gain reaches its maximum, while the radiation of the right-hand circularly polarized (RHCP) component represented by the blue line is extremely low in this direction, indicating that the antenna has excellent circular polarization axial ratio characteristics at this frequency point, realizing efficient and pure left-hand circularly polarized wave radiation.

[0105] It should be noted that the RF module provided in this embodiment of the invention has the same technical effect as the zero DC power consumption multi-bit terahertz phased array antenna described above, and will not be repeated here.

[0106] It should be noted that in the description of the embodiments of the present invention, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. The terms "upper," "lower," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly, for example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A zero-DC-power multi-bit terahertz phased array antenna, characterized in that, The device includes a dielectric substrate, a basic radiating unit, a memory metal unit, and a control unit. The basic radiating unit is disposed on the radiating layer of the dielectric substrate, and each basic radiating unit is associated with multiple memory metal units based on the number of bits. The control unit is disposed within the dielectric substrate or above the memory metal units and is used to apply an instantaneous excitation to one or more memory metal units associated with the basic radiating unit when the basic radiating unit needs to switch phase states. The memory metal unit deforms after being subjected to the instantaneous excitation and maintains the deformed state until it is subjected to the next instantaneous excitation.

2. The zero-DC-power multi-bit terahertz phased array antenna according to claim 1, characterized in that, The basic radiating unit includes a circular radiator. Multiple memory metal units are integrated in the circular radiator at the opening of the ring, the coupling gap, or the feed point. Multiple preset contact points are distributed at 45° intervals along the circumference of the ring. The anchor end of each memory metal unit is located on the dielectric substrate. The free end of each memory metal unit is initially connected to the contact point, and disconnected from the contact point after being subjected to instantaneous excitation.

3. The zero-DC-power multi-bit terahertz phased array antenna according to claim 2, characterized in that, The number of bits is two. The annular radiator integrates four memory metal units at the opening of the annular ring, the coupling gap, or the feed point. The annular radiator has four preset contact points distributed every 45° along the circumference of the annular ring. When the free end of any memory metal unit is connected to the contact point, it is in a conductive state; otherwise, it is in a cut-off state.

4. The zero-DC-power multi-bit terahertz phased array antenna according to claim 3, characterized in that, The four memory metal units are sequentially designated as a first memory metal unit, a second memory metal unit, a third memory metal unit, and a fourth memory metal unit. When only the first memory metal unit is in the conducting state, the response phase of the ring radiator is 0°. When only the second memory metal unit is in the conducting state, the response phase of the ring radiator is 90°. When only the third memory metal unit is in the conducting state, the response phase of the ring radiator is 180°. When only the fourth memory metal unit is in the conducting state, the response phase of the ring radiator is 270°.

5. The zero-DC power consumption multi-bit terahertz phased array antenna according to any one of claims 2 to 4, characterized in that, The geometry of the annular radiator is determined based on the terahertz frequency band.

6. The zero-DC power consumption multi-bit terahertz phased array antenna according to any one of claims 2 to 4, characterized in that, When the free end of the shape memory metal unit is in the conductive state, it forms a direct metal-metal contact with the contact point.

7. The zero-DC-power multi-bit terahertz phased array antenna according to claim 1, characterized in that, The dielectric substrate includes a radiation layer, an isolation layer, and a control layer arranged from top to bottom. The radiation layer is used to radiate electromagnetic waves, the control layer is used to control the realization of photothermal conversion, and the isolation layer is used to isolate thermal coupling between different basic radiation units. The control layer is provided with a micro heater to form a thermal control path, or the radiation layer is provided with a wave-transparent photothermal conversion film to form a thermal control path.

8. The zero-DC power consumption multi-bit terahertz phased array antenna according to claim 7, characterized in that, The isolation layer includes a thermal resistance trench, which is an air gap etched on the isolation layer of the dielectric substrate, with a depth penetrating the isolation layer and a width less than 1 / 10 of the cell pitch.

9. The zero-DC-power multi-bit terahertz phased array antenna according to claim 7, characterized in that, The radiating layer is also used to form a radio frequency signal transmission path with the basic radiating unit, and the radio frequency signal transmission path is independent of the thermal control path in terms of physical structure and spatial layout.

10. The zero-DC power consumption multi-bit terahertz phased array antenna according to claim 1, characterized in that, The control unit is located above the memory metal unit and includes a laser array. The surface of the memory metal unit is provided with a photothermal conversion layer. The control unit emits lasers to one or more memory metal units associated with the basic radiation unit, and the photothermal conversion layer on the surface of the memory metal unit converts the lasers into heat.

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