antenna

Abstract

Antenna and method for manufacturing the antenna According to one aspect of the present invention, there is provided an antenna including a magnetostrictive layer configured to convert a magnetic field of a detected electromagnetic wave into mechanical strain in a reception mode, and a piezoelectric layer configured to receive the strain from the magnetostrictive layer and generate a voltage output based thereon in the reception mode, wherein the piezoelectric layer includes a memristive material.

Description

Technical Field

[0001] The present invention generally relates to antennas, and more particularly to antennas that include memristive materials. Related antenna arrays and methods are also provided.

Background Art

[0002] Wireless communication systems operating in the radio frequency range require antennas for converting electromagnetic waves into currents indicative of received signals and vice versa. Typically, an antenna is driven by an analog circuit connected to a signal processing unit. In most systems, the signals received by the antenna do not move directly to the logic elements responsible for decoding the signals and extracting the transmitted information. Instead, the signals usually have to pass through modules such as an analog-to-digital (ADC) converter, memory, and / or a digital signal processor (DSP). Each of these modules has associated noise sources, thereby degrading the signal-to-noise ratio (SNR) of the system.

[0003] Furthermore, such modules include parasitic elements that introduce propagation delays, increasing the time interval between the signals received by the antenna and the information contained in the extracted signals. Therefore, different approaches are needed to provide a device that can extract the information contained in the received signal more quickly.

[0004] An exemplary object of an exemplary embodiment of the present invention is to at least partially avoid or overcome one or more drawbacks of the prior art, whether specified herein or elsewhere, or at least provide a viable alternative to existing devices and methods.

Summary of the Invention

[0005] According to one aspect of the present invention, an antenna is provided comprising a magnetostrictive layer configured to convert the magnetic field of a detected electromagnetic wave into mechanical strain in a receiving mode, and a piezoelectric layer configured to receive strain from the magnetostrictive layer and generate a voltage output thereon, wherein the piezoelectric layer comprises a memristic material. Thus, an antenna with intrinsic memory and signal processing capabilities can be provided, thereby enabling faster extraction of information contained in the received signal. The calculations can be performed directly in the memory element, which also performs sensing operations to detect and process the received signal.

[0006] In transmission mode, the piezoelectric layer may be configured to receive a voltage input and generate mechanical strain based on it, and the magnetostrictive layer may be configured to receive the mechanical strain generated by the piezoelectric layer and generate and output electromagnetic waves based on it. Thus, the antenna can use a piezoelectric layer containing memristic material in both receiving and transmitting signals.

[0007] The piezoelectric layer may be arranged so as to be set to a specified condition by the application of voltage and / or charge. Therefore, due to the inherent properties of the memristic material contained therein, the piezoelectric layer can be set to the desired condition in an easy manner.

[0008] The piezoelectric layer may be configured to be set to specified conditions before the antenna's receiving and / or transmitting operations are performed. Thus, the antenna can be preset (in other words, pre-programmed) before normal use and can therefore be considered a programmable system.

[0009] Setting a piezoelectric layer to specific conditions may involve changing its conductance by applying a voltage. The conductance of a memristic material is closely related to the synaptic load, i.e., the strength of the synaptic connection. Therefore, by applying a voltage, the conductance can be decreased and / or increased to realize the forgetting and learning behaviors of the piezoelectric layer, respectively, thereby exhibiting synaptic behavior similar to that of a biological system.

[0010] The conductance of the piezoelectric layer can be changed based on at least one of the frequency and polarity of the applied voltage. Since the conductance of the memristic material depends on the shape and frequency of the stimulated pulse, the properties of the piezoelectric layer can be easily altered.

[0011] The piezoelectric layer may be configured to retain a set condition after the application of a voltage. Therefore, the piezoelectric layer can function as a non-volatile memory due to the presence of the memristic material.

[0012] The piezoelectric layer can be configured to generate a voltage output based on the strain it receives and the charge resulting from the set conditions. This allows the antenna to generate an output based not only on the detection signal but also on the set state of the piezoelectric layer.

[0013] The piezoelectric layer may be configured to generate a voltage output when the charge resulting from the strain it receives equals a threshold defined based on the set conditions of the piezoelectric layer. Thus, the antenna can ignore signals that do not possess the desired characteristics as noise and generate an output only when a pre-programmed signal pattern is acquired. This is done by the antenna without interaction with additional processing units, thereby reducing the signal propagation delay and thus the time it takes for the antenna to extract information from the desired signal.

[0014] The memristic material may contain annealed aluminum nitride (AlN). Therefore, the antenna can be manufactured using readily available materials, thereby improving manufacturability and reducing costs.

[0015] According to another aspect of the present invention, an antenna array comprising a plurality of antennas described herein is provided. Thus, an antenna having unique signal processing capabilities can be provided, thereby enabling faster extraction of information contained in the received signal. The calculations can be performed directly in the memory element, which also performs sensing operations, thereby detecting and processing the received signal.

[0016] Each of the multiple antennas in an antenna array can be arranged to be individually set to conditions defined by the application of voltage. Therefore, since each individual antenna can be set to conditions that enable the identification of a specific signal, greater programmability can be achieved.

[0017] According to another aspect of the present invention, a method for manufacturing an antenna is provided, which includes the steps of providing a piezoelectric layer containing a memristive material and providing a magnetostrictive layer disposed on the piezoelectric layer. Thus, an antenna having inherent signal processing capabilities can be provided, thereby enabling faster extraction of information contained in the received signal. The calculations can be performed directly in the memory element, which also performs sensing operations to detect and process the received signal.

[0018] This method may include the step of providing annealed aluminum nitride (AlN) as the memristic material. Therefore, the antenna can be manufactured using readily available materials, thereby reducing costs. [Brief explanation of the drawing]

[0019] Next, embodiments of the present invention will be described merely as examples with reference to the accompanying drawings. [Figure 1]Figure 1 schematically shows an antenna according to an exemplary embodiment. [Figure 2] Figure 2 schematically illustrates a thin-film bulk acoustic resonator (FBAR) with a piezoelectric layer according to an exemplary embodiment. [Figure 3] Figure 3 schematically illustrates an antenna array comprising multiple antennas according to an exemplary embodiment. [Figure 4] Figure 4 schematically illustrates a method for manufacturing an antenna according to an exemplary embodiment. [Modes for carrying out the invention]

[0020] As mentioned above, existing antennas have many drawbacks. These range from the considerable cost associated with existing antennas due to the amount of circuitry required, to the delay in extracting information from the signal received by the antenna, or the amount of noise that is mistakenly picked up instead of the desired signal. In general, there is no relatively inexpensive, flexible, and simple design that allows the antenna to process the received signal in an element that also performs sensing operations.

[0021] This disclosure recognizes that problems associated with existing methods can be overcome in an inexpensive and effective manner. In particular, this disclosure provides a magnetoelectric antenna comprising a memristive material.

[0022] Figure 1 schematically depicts an antenna according to an exemplary embodiment. In this example, the antenna 100 comprises a magnetostrictive layer 102 and a pressure transmission layer 104. Importantly, the piezoelectric layer 104 contains a memristive material.

[0023] Antenna 100 may be a thin-film bulk acoustic resonator (FBAR) antenna. Since antenna 100 operates at the acoustic resonant frequency rather than the EM wave resonant frequency, the antenna size can be significantly reduced to a size comparable to the electromagnetic wavelength without performance degradation. Therefore, antenna 100 may be particularly suitable for applications where high resonant frequency, small size, and low weight are desirable.

[0024] Antenna 100 transmits and receives electromagnetic waves by means of the magnetoelectric effect at its acoustic resonance frequency. During the reception operation of Antenna 100, the magnetostrictive layer 102 is configured to convert the magnetic field of the detected electromagnetic wave into mechanical strain to be received by the piezoelectric layer 104. The piezoelectric layer 104 generates a voltage output based on the strain received from the magnetostrictive layer 102. Specifically, in the reception mode, the magnetostrictive layer 102 senses the H component of the electromagnetic wave and induces vibrational deformation transmitted to the piezoelectric layer 104. The piezoelectric layer 104 can then generate a voltage output.

[0025] Conversely, during the transmission operation of Antenna 100, the piezoelectric layer 104 is configured to receive a voltage input and generate mechanical strain based thereon. Such a voltage input can originate from Antenna 100 itself or from external components of the antenna system. The magnetostrictive layer 102 receives the mechanical strain generated by the piezoelectric layer 104 and is configured to generate and output an electromagnetic wave based thereon. Specifically, the piezoelectric layer 104 can receive an input of an alternating voltage and generate a mechanical deformation that vibrates. In response to the mechanical excitation, the magnetostrictive layer 102 can then induce magnetization vibrations or magnetic currents that radiate an electromagnetic wave and thus transmit a signal.

[0026] As described above, the piezoelectric layer 104 includes a memristive material. In particular, the memristive material exhibits non-volatile memory characteristics and continuous conductance change characteristics, thus making it suitable for use in neuromorphic systems. The memristive material can be compared to synapses in the brain.

[0027] The cellular mechanism underlying learning and memory in the human and animal brains is called long-term potentiation (LTP). LTP is the sustained strengthening of synapses based on recent activity patterns. These are patterns of synaptic activity that result in a long-lasting increase in signal transmission between two neurons. Short-term potentiation (STP) refers to the process in which synaptic transmission is temporarily enhanced. Thus, STP can be thought of as short-term memory. STP can be transformed into LTP through a process of repetition, which involves many biological changes.

[0028] Generally, a memristor (i.e., a memristic device) is a two-terminal resistive switching device that can maintain its internal resistance state according to the history of applied voltage / current. The two terminals behave similarly to the axon and dendrite connecting the presynaptic and postsynaptic neurons, and the conductance of the switching layer is comparable to the weight of the synapse. By changing the conductance of the memristor to a set state, the device can be used to replicate the memory function of the human brain by simulating the transition from an unmemorized state to STP and LTP states.

[0029] The piezoelectric layer 104 may be set to a specified condition by applying a voltage. Setting the piezoelectric layer 104 to a specified condition may include changing the conductance of the piezoelectric layer 104 by applying a voltage or charge. In particular, by applying a voltage to the piezoelectric layer 104, the conductance of the memristic material contained in the piezoelectric layer 104 can be changed, thereby realizing the memory function described above. The voltage applied to the piezoelectric layer 104 may be an external bias voltage / charge, or an internal charge generated by the antenna 100 due to the piezoelectric effect.

[0030] Similarly, since the two quantities are essentially related, the electrical resistance of the piezoelectric layer 104 can also be modified through the application of a voltage. In particular, the resistance of the memristic material contained in the piezoelectric layer 104 can be altered in this way.

[0031] The condition (or state) of the piezoelectric layer 104 may depend on the previous state, the amplitude of the applied voltage, and the voltage / signal acquisition time. For example, after the application of a first voltage, the condition of the piezoelectric layer 104 may change from the initial state to the first state. If a second voltage is applied to the piezoelectric layer 104 after the first voltage has been applied, the condition of the piezoelectric layer 104 will change from the first state to the second state.

[0032] The conductance of the piezoelectric layer 104 can be changed based on at least one of the frequency and polarity of the applied voltage. For example, by applying a continuous positive voltage pulse, the conductance of the memristic material contained in the piezoelectric layer 104 can be changed from an initial state to a higher state. Conversely, by applying a negative voltage pulse, the conductance of the memristic material 104 can be changed from an initial state to a lower state. The conductance of the memristic material can also be changed by modifying the duration of the applied voltage.

[0033] The piezoelectric layer 104 may be configured to maintain a set condition after a voltage is applied. As described above, a voltage can be applied to change the conductance of the memristic material contained in the piezoelectric layer 104, changing it from an initial state to a higher state. This change in the conductance of the memristic material is retained for a period of time after the voltage application is stopped, thereby enabling the non-volatile memory operation of the memristic material. In other words, it is not necessary to apply a constant voltage to change the conductance of the memristic material in the piezoelectric layer 104. By changing the conductance / resistance of the memristic material contained in the piezoelectric layer 104, the resonant frequency of the antenna 100 can be changed.

[0034] The holding time can be defined as the amount of time the piezoelectric layer 104 maintains its set state, for example, the amount of time the memristic material contained in the piezoelectric layer 104 maintains a state with changed conductance. The holding time can be increased by increasing at least one of the number of voltage pulses, pulse width, and / or pulse amplitude.

[0035] The piezoelectric layer 104 may be positioned to be set to a defined condition before the antenna's receiving and / or transmitting operation is performed. In this way, the antenna 100 may be pre-programmed or pre-set to a defined condition.

[0036] As described above, distortion is generated by the magnetostrictive layer 102 by converting the magnetic field of the detected electromagnetic wave, i.e., the signal detected by the antenna 100. The piezoelectric layer 104 can be configured to generate a voltage output based on the distortion received by the piezoelectric layer 104 and the charge resulting from the set conditions. Therefore, the voltage output generated by the piezoelectric layer 104 may depend not only on the detected electromagnetic wave but also on the set conditions of the piezoelectric layer 104. For example, the voltage output may depend on the received distortion resulting from the detected electromagnetic wave and the modified conductance of the memristic material contained in the piezoelectric layer 104.

[0037] The piezoelectric layer 104 may be configured to generate a voltage output when the charge resulting from the strain it receives is equal to a threshold defined based on the settings of the piezoelectric layer. In other words, the piezoelectric layer 104 may be configured to generate a voltage output only when a pre-programmed signal pattern is acquired. The piezoelectric layer 104 may also be pre-programmed to respond to a specific signal pattern by utilizing the memory capability of the memristic material contained therein. This can be achieved by setting the piezoelectric layer 104 to predefined conditions corresponding to the signal pattern that the user wants to detect.

[0038] In detail, the signal recognition process by the memristive material contained in the piezoelectric layer 104 can utilize the switching characteristics of the memristor. As described above, the conductance and resistance of the memristive material can be changed by applying a voltage.

[0039] Figure 2 schematically illustrates a thin-film bulk acoustic wave resonator (FBAR) 200 comprising a piezoelectric layer according to an exemplary embodiment. The piezoelectric layer can be considered equivalent to the piezoelectric layer 104 shown in Figure 1. The piezoelectric layer is sandwiched between a first electrode 210 (e.g., upper electrode) and a second electrode 216 (e.g., lower electrode) to form the thin-film bulk acoustic wave resonator (FBAR) 200.

[0040] The piezoelectric layer may comprise multiple layers. These multiple layers may include a switchable resistive layer 212. The resistance of the switchable resistive layer 212 may be variable between a high-resistance state and a low-resistance state. The multiple layers may also comprise a capacitive layer 214.

[0041] The charge generated by the piezoelectric layer, caused by the detected electromagnetic wave, can modulate the voltage across the capacitive layer 214 of the memristive material contained in the piezoelectric layer. The overall resistance / impedance of the antenna 100 can be controlled by a switchable resistive layer 212. The resulting change in at least one of the conductance, resistance, impedance, and capacitance of the memristive material contained in the piezoelectric layer can modulate the resonant frequency of the FBAR 200, thereby changing the resonant frequency of the antenna 100.

[0042] As described above, the antenna 100 operates by converting electromagnetic signals into mechanical strain generated in the magnetostrictive layer 102. The mechanical strain transmitted to the piezoelectric layer 104 is converted into a voltage. Specifically, this induces a potential difference in the capacitive layer 214. When the voltage across the capacitive layer 214 reaches a switching threshold, switching can occur in the memristive material. The switching threshold may be pre-programmed in the memristive material. The switching threshold can be correlated with known signal patterns that are expected to trigger switching in the memristive material, so that switching occurs only when a desired signal pattern is detected by the antenna 100.

[0043] Signals that do not correspond to the desired signal pattern may be treated as noise by antenna 100 and dropped during reception. In other words, such signals do not need to trigger the switching of the memristic material.

[0044] The memristic material may contain annealed aluminum nitride (AlN). However, those skilled in the art will understand that other piezoelectric materials exhibiting memristic properties may also be used.

[0045] Annealing may include O2 annealing. O2 annealing can reduce the number of oxygen vacancies at the interface between the aluminum nitride layer and the upper electrode of the FBAR. A high dielectric thin film can be formed through a heat treatment process. This high dielectric constant layer allows the memristive material to exhibit synaptic behavior.

[0046] Importantly, the above configuration of antenna 100 is particularly useful when it is necessary to rapidly detect and identify signals with specific characteristics. The piezoelectric layer 104 uses the memristic material contained within it to trigger a response only when a desired signal pattern is detected, thus significantly reducing or eliminating the need for interaction with a processing unit (such as a digital signal processor). This allows calculations to be performed in the piezoelectric layer 110 without changing the mechanical stiffness of the piezoelectric layer 104, which reduces its compliance and decreases the efficiency of electromagnetic wave signal conversion. Therefore, improvements can be achieved over existing systems by enabling signal processing in the piezoelectric layer 110 without changing the mechanical state of the piezoelectric layer 104.

[0047] Furthermore, by enabling direct signal processing within the antenna 100, the signal path can be shortened, and therefore the speed at which information can be extracted from the detected signal can be accelerated. Thus, the antenna 100 may be suitable for applications requiring minimal delay, such as detecting radio frequency (RF) signal patterns reflected from fast-moving objects.

[0048] Figure 3 schematically illustrates an antenna array comprising multiple antennas according to an exemplary embodiment. The antenna array 1000 comprises multiple antennas 100. The resonant frequencies of the multiple antennas 100 may be identical. Alternatively or additionally, the resonant frequencies of each of the multiple antennas 100 may be different so that multiple different resonant frequencies can be sensed independently. That is, each of the multiple antennas 100 may be arranged to be individually set to conditions defined by the application of a voltage in order to enable multi-channel operation. Detected electromagnetic waves can be processed in parallel by each antenna 100 of the antenna array 1000. This can be achieved by individually addressing each antenna 100 of the antenna array 1000 using a network of row multiplexers 302 and column multiplexers 304.

[0049] Figure 4 schematically illustrates a method for manufacturing an antenna according to an exemplary embodiment. The antenna may be, for example, antenna 100 as described herein. The method includes, in step 402, providing a piezoelectric layer containing a memristive material. As described above in relation to Figure 1, the piezoelectric layer uses the memristive material contained therein to trigger a response only when a desired signal pattern is detected, so the need for interaction with a processing unit (such as a digital signal processor) is significantly reduced or eliminated. Furthermore, by enabling signal processing directly within the antenna, the signal path can be shortened, and therefore the speed at which information can be extracted from the detected signal can be accelerated.

[0050] In step 404, the method includes providing a magnetostrictive layer disposed on a piezoelectric layer. In another embodiment, the method may first include providing a magnetostrictive layer, the piezoelectric layer comprising a memristive material disposed on the magnetostrictive layer. By alternating the order of the layers, the performance of the antenna for a particular application can be improved depending on the particular design. The method may also include providing multiple vertical stacks of piezoelectric-magnetostrictive layer pairs.

[0051] The method may further include the step of providing annealed aluminum nitride (AlN) as a memristive material. However, those skilled in the art will understand that other piezoelectric materials exhibiting memristive properties may also be used. The following is a direct reproduction of the claims as originally filed. [C1] It is an antenna, In receiving mode, a magnetostrictive layer configured to convert the magnetic field of the detected electromagnetic wave into mechanical strain, In receiving mode, the system includes a piezoelectric layer configured to receive strain from the magnetostrictive layer and generate a voltage output based on it. Here, the piezoelectric layer comprises a memristic material, and the antenna is provided. [C2] The antenna according to C1, wherein in transmission mode, the piezoelectric layer is configured to receive a voltage input and generate mechanical strain thereon, and the magnetostrictive layer is configured to receive the mechanical strain generated by the piezoelectric layer and generate and output electromagnetic waves thereon. [C3] The antenna according to C1 or C2, wherein the piezoelectric layer is arranged to be set to a specified state by the application of voltage and / or charge. [C4] The antenna according to C3, wherein the piezoelectric layer is arranged to be set to the specified conditions before the receiving and / or transmitting operations of the antenna are performed. [C5] The antenna according to C3 or C4, wherein setting the piezoelectric layer to the specified conditions is performed by changing the conductance of the piezoelectric layer by applying the voltage. [C6] The antenna according to C5, wherein the conductance of the piezoelectric layer changes based on at least one of the frequency of the applied voltage and the polarity of the applied voltage. [C7] The antenna according to any one of C3 to 6, wherein the piezoelectric layer is configured to maintain the set conditions after the voltage is applied. [C8] The antenna according to any one of C3 to 7, wherein the piezoelectric layer is configured to generate the voltage output based on the received strain of the piezoelectric layer and the charge resulting from the set conditions. [C9] The antenna according to C8, wherein the piezoelectric layer is configured to generate the voltage output when the charge resulting from the received strain is equal to a threshold defined based on the set conditions of the piezoelectric layer. [C10] The aforementioned memristive material comprises annealed aluminum nitride (AlN), as described in any one of C1 to C9, for the antenna. [C11] An antenna array comprising multiple antennas as described in any one of items C1 to C10. [C12] The antenna array according to C11, wherein each of the plurality of antennas is arranged to be individually set to conditions defined by the application of voltage. [C13] A method for manufacturing an antenna, To provide a piezoelectric layer containing a memristic material, A method comprising providing a magnetostrictive layer disposed on the piezoelectric layer. [C14] The method according to C13, comprising the step of providing annealed aluminum nitride (AlN) as the memristive material.

Claims

1. It is an antenna, In receiving mode, a magnetostrictive layer configured to convert the magnetic field of the detected electromagnetic wave into mechanical strain, In receiving mode, the system includes a piezoelectric layer configured to receive strain from the magnetostrictive layer and generate a voltage output based on it. Here, the piezoelectric layer comprises a memristic material, Here, the piezoelectric layer is arranged to be set to a specified condition by the application of voltage and / or charge, and the specified condition is set based on the intrinsic properties of the memristic material. antenna.

2. The antenna according to claim 1, wherein in transmission mode, the piezoelectric layer is configured to receive a voltage input and generate mechanical strain thereon, and the magnetostrictive layer is configured to receive the mechanical strain generated by the piezoelectric layer and generate and output electromagnetic waves thereon.

3. The antenna according to claim 1, wherein the piezoelectric layer is arranged to be set to the specified conditions before the receiving and / or transmitting operations of the antenna are performed.

4. The antenna according to claim 1, wherein setting the piezoelectric layer to the specified conditions is further comprising changing the conductance of the piezoelectric layer by applying the voltage.

5. The antenna according to claim 4, wherein the conductance of the piezoelectric layer changes based on at least one of the frequency of the applied voltage and the polarity of the applied voltage.

6. The antenna according to claim 1, wherein the piezoelectric layer is configured to maintain the set specified conditions after the voltage is applied.

7. The antenna according to claim 1, wherein the piezoelectric layer is configured to generate the voltage output based on the received strain of the piezoelectric layer and the charge resulting from the set specified conditions.

8. The antenna according to claim 7, wherein the piezoelectric layer is configured to generate the voltage output when the charge resulting from the received strain is equal to a threshold defined based on the set specified conditions of the piezoelectric layer.

9. The antenna according to claim 1, wherein the memristic material comprises annealed aluminum nitride (AlN).

10. An antenna array comprising a plurality of antennas as described in claim 1.

11. The antenna array according to claim 10, wherein each of the plurality of antennas is arranged to be individually set to the specified conditions by the application of a voltage.

12. A method for manufacturing an antenna, To provide a piezoelectric layer containing a memristic material, The invention provides a magnetostrictive layer disposed on the piezoelectric layer, Here, the piezoelectric layer is arranged to be set to a specified condition by the application of voltage and / or charge, and the specified condition is set based on the intrinsic properties of the memristic material. method.

13. The method according to claim 12, further comprising the step of providing annealed aluminum nitride (AlN) as the memristive material.

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