173 results about "Leaky wave antenna" patented technology

The invention discloses an SSPP leaky-wave antenna and a design method thereof, and belongs to the technical field of wireless communication, and the antenna comprises a dielectric substrate, and a positive microstrip line and a negative microstrip line which are correspondingly arranged on the upper surface and the lower surface of the dielectric substrate; the positive microstrip line and the negative microstrip line are respectively symmetrical about two current transmission ends; and the SSPP structure of the middle section of the positive microstrip line and the SSPP structure of the middle section of the negative microstrip line are arranged in a way that the groove openings are opposite to each other. According to the invention, high-gain signal radiation and multi-angle beam scanning can be realized.

The invention relates to a reconfigurable dual-mode leaky-wave antenna with global scanning capability and a reconfiguration method, the leaky-wave antenna comprises a double-layer slow-wave waveguide structure formed by an upper metal conductor and a lower metal conductor, and the upper metal conductor and the lower metal conductor are separated by a dielectric substrate; the double-layer slow-wave waveguide structure comprises a plurality of periodic units, and a plurality of T-shaped structures with opposite directions are processed on upper and lower layers of metal conductors of each periodic unit to form a plurality of grooves; a variable capacitance diode is embedded into the tail end of a slot arm of the upper-layer metal conductor and is electrically connected with the lower-layer metal conductor through a metal via hole, and a closed loop is formed between the upper-layer metal conductor and the lower-layer metal conductor; a plurality of elliptical radiation patches are arranged at the top of a slot arm of the lower metal conductor at intervals and used for radiation leakage of the slow wave waveguide, and continuous frequency scanning covering 180 degrees is achieved; according to the invention, two modes of frequency scanning and fixed-frequency scanning are fused, 180-degree global scanning can be realized in any frequency reconfigurable interval, and beams can be flexibly reconstructed through multiple control strategies under a fixed-frequency condition.

The invention relates to the technical field of wireless communication and sensing, and particularly discloses a holographic amplitude weighting-based two-dimensional antenna array multi-beam scanning method, which comprises the following steps of: determining the position information of each radiation unit in a two-dimensional antenna array, including calculating the interval and the arrangement mode of the units; an amplitude weighted value of each radiation unit is generated according to the target wave direction, a two-dimensional multi-beam holographic amplitude weighting technology is used, and the radiation unit amplitude weighted values are determined through the two-dimensional multi-beam holographic amplitude weighting technology; generating a corresponding binary discretization coding sequence based on the amplitude weighted value so as to control the excitation amplitude of each radiation unit; and designing a liquid crystal-based Ka-band two-dimensional holographic beam scanning leaky-wave antenna square array, and regulating and controlling a radiation pattern of a two-dimensional antenna array through the coding sequence to realize multi-beam scanning.

The technology described herein is directed towards a transceiver with beam scanning capability based on leaky wave antenna technology and substrate integrated waveguide technology, along with a metallic covering that determines which direction the antenna radiates signals. The leaky wave antenna can include different respective groups of slot pairs having different respective periodicities, corresponding to different respective beam steering directions. One or more metallic covers can be used to cover some of the slot pair sections, such that the sections under cover behave like a conventional substrate integrated waveguide and the exposed section(s) behave like conventional leaky wave antennas. The metallic covers can be moved as desired, such as attached via magnets. The transceiver can thus steer signals to a wearable or portable device that includes a passive metasurface while mitigating null regions. The slot pairs can be asymmetrical reflection-canceling slot pairs, to achieve broadside radiation while avoiding band-stop effects.

The invention provides an electric control beam scanning leaky-wave antenna and communication equipment, and the leaky-wave antenna comprises a gap waveguide which comprises a strip-shaped ridge, the gap waveguide is used for transmitting electromagnetic waves in a traveling wave manner, and the strip-shaped ridge extends in the transmission direction of the electromagnetic waves and is arranged in the gap waveguide; the plurality of radiation units are arranged on the side wall of the gap waveguide, each radiation unit comprises a radiation slot and an electric control switch, and the radiation slots are used for leaking electromagnetic waves in the gap waveguide to a free space to form wave beams; and the electric control switch is used for controlling the working state of the radiation slot so as to realize beam scanning. According to the leaky-wave antenna provided by the invention, the beam tilt characteristic of the antenna can be improved, and the communication quality of the antenna is improved.

The invention discloses a multi-mode circularly polarized OAM (orbital angular momentum) filtering antenna based on an artificial surface plasmon. According to the antenna, the SSPP leaky-wave antenna and the HMSIPW filter are integrated, so that efficient emission of multi-mode OAM beams is realized, and the antenna has low axial ratio, high gain and good directional diagram matching performance; the SSPP leaky-wave antenna is composed of an Archimedes spiral line type SSPP waveguide and annularly distributed patches, wherein the SSPP waveguide realizes accurate regulation and control of dispersion characteristics through the combination of periodic sawtooth comb lines and uniform spiral lines; the HMSIPW filter is composed of a dielectric substrate layer, a metalized through hole and a gradient rectangular structure, impedance matching of a micro-strip and double lines is achieved, insertion loss is reduced, and radiation performance is improved. Compared with a traditional design, a filtering function is integrated, higher harmonic radiation and low-purity high-mode OAM are inhibited through the overall design, and selectivity and radiation energy uniformity are improved.

The invention relates to the technical field of antenna control, and discloses a control method for a leaky-wave antenna and a communication device. The method comprises the following steps: measuring the dispersion characteristic of the leaky-wave antenna, establishing a second-order nonlinear mapping relation between a propagation constant and a control voltage, and obtaining a dispersion control parameter group; reversely deducing the target beam directional angle to obtain a target propagation constant, and calculating an initial voltage value of each control unit in combination with the parameter group to form a voltage gradient control sequence; correcting the propagation constant of each unit by adopting a distance compensation algorithm, and recalculating to obtain distance self-adaptive voltage distribution data; and detecting a beam quality factor in real time, updating voltage distribution data through a gradient descent algorithm when the beam quality factor deviates from a target value, and outputting a control voltage sequence to drive each control unit. The leaky-wave antenna control method and device solve the problems that in an existing leaky-wave antenna control technology, the beam quality is reduced and the data rate is sharply attenuated during long-distance transmission, and the beam control precision and the long-distance transmission performance of the leaky-wave antenna in the terahertz frequency band are improved.

The invention provides a fixed-frequency beam scanning leaky-wave antenna and electronic equipment. The leaky-wave antenna comprises a first microstrip line and a second microstrip line, wherein the first microstrip line and the second microstrip line are used for transmitting radio frequency signals and are arranged at an interval; the N antenna units are connected to the first microstrip line and the second microstrip line, and each antenna unit comprises a first switch and a second switch; a first stub and a second stub, and an antenna. According to the technical scheme, the leaky-wave antenna is simple in structure, easy to process, high in expansibility and capable of reducing parasitism, transmission loss, element loss and the like.

The invention discloses a variable capacitance diode-based element grating leaky-wave antenna adjustable beam control method. The method comprises the following steps of S1, researching and analyzing a super grating beam conversion mechanism; a plane super grating mechanism under anisotropic, uniform and continuous periodic boundary conditions is researched; s2, carrying out the transmission mode and optimization design of the Floquet-Blocch theorem according to the super grating; the FB mode is researched, and a tool used for super grating parameters is designed to eliminate the bad FB mode; s3, analyzing and designing the super grating leaky-wave antenna; the analytic field and current of the synthetic super grating are researched in the leaky-wave antenna frame to customize the performance in the aspects of phase, beam shape and polarization; s4, designing and analyzing the electric tuning wave beam control super grating leaky-wave antenna; according to the variable capacitance diode-based element grating leaky-wave antenna adjustable wave beam control method, a high-efficiency structure platform which is tuned by a tunable material with a simple structure is adopted, and a road is laid for a new generation of high-efficiency special grating.

The invention discloses a three-unit leaky-wave antenna array structure based on a dielectric ridge parallel plate waveguide, which comprises the following steps: S1, designing a three-unit array structure based on the coupling characteristic of the dielectric ridge parallel plate waveguide, and feeding a two-port array antenna in parallel by a probe; and S2, according to the product theorem of a directional diagram, determining the gap design of the three units according to the relationship between the gap size and the leakage amount, so as to design a scanning beam meeting the requirements of narrow lobe and high gain. The leaky-wave antenna array structure with the narrow beam and high gain characteristics is provided for the requirements of high signal strength and strong anti-interference performance in a long-distance point-to-point communication system, the antenna can provide better directivity and higher communication quality, and meanwhile it is guaranteed that the antenna has the advantages of being compact in structure and small in size; therefore, the method can be applied to wireless energy transmission systems such as a satellite communication system, a radar system and the Internet of Things.

The invention belongs to the technical field of antennas, and discloses a dual circularly polarized leaky-wave antenna based on a substrate integrated waveguide, which comprises a feed structure and a radiation structure, the feed structures are symmetrically arranged at the two ends of the radiation structure, and the feed structures and the radiation structure are substrate integrated waveguides; the feed structure is used for converting received external electromagnetic energy into guided electromagnetic waves and has the characteristic of widening impedance; wherein a gradient coplanar waveguide transmission line is designed in the feed structure; the radiation structure is used for converting the guided electromagnetic waves transmitted by the feed structure into circularly polarized electromagnetic waves in a free space; wherein a grid window leaky wave structure is designed in the radiation structure; by combining the leaky-wave antenna and the substrate integrated waveguide technology, the gradient coplanar waveguide transmission line is designed on the feed structure, and the grid window leaky-wave structure is designed on the radiation structure, so that the millimeter wave working frequency band requirement is met, and the antenna has the characteristics of wide axial ratio bandwidth, low side lobe, large scanning range, low profile and low cost.

The present application provides an electronically controlled beam scanning leaky-wave antenna and a communication device. The leaky-wave antenna comprises: a gap waveguide, comprising a strip-shaped ridge, wherein the gap waveguide is used for transmitting electromagnetic waves in the form of traveling waves, and the strip-shaped ridge extends in the gap waveguide in the transmission direction of the electromagnetic waves; and a plurality of radiation units, arranged on the side wall of the gap waveguide, wherein each radiation unit comprises a radiation slot and an electrically controlled switch, the radiation slot is used for leaking electromagnetic waves in the gap waveguide into a free space to form a beam, and the electrically controlled switch is used for controlling a working state of the radiation slot so as to realize beam scanning. The leaky-wave antenna provided by the present application can improve the beam tilt characteristic of the antenna, and improve the communication quality of the antenna.

The invention provides an arrival wave angle estimation method based on a zero scanning leaky-wave antenna. A rectangular waveguide is selected as a basic structure to design a periodic leaky-wave antenna only working in a-1 harmonic state; designing necessary antenna simulation parameters; a first leaky-wave antenna is designed; adjusting the gap interval p, and designing a second leaky-wave antenna; obtaining pattern functions of the first leaky-wave antenna and the second leaky-wave antenna; proper amplitude and phase parameters are selected for directional diagram synthesis, and a new directional diagram function is obtained; constructing an array guiding matrix suitable for the MUSIC algorithm; signal sources are arranged at different positions, simulation testing is carried out through MATLAB, and the incoming wave angle estimation capability of the zero-point scanning leaky-wave antenna is verified. According to the invention, a feasible technical path is provided for high-precision positioning and tracking application in future 6G mobile communication. The antenna is especially suitable for application in millimeter wave and terahertz frequency bands, such as vehicle-mounted communication, unmanned aerial vehicle platforms, military electronic countermeasures and the like.

The invention belongs to the field of millimeter wave point-to-point communication, and particularly relates to a broadband fixed-beam leaky-wave antenna with a filtering characteristic. The substrate integrated coaxial line transmission structure is adopted to feed the two ends of the leaky-wave structure, and the substrate integrated coaxial line transmits quasi-TEM waves and has a very weak dispersion characteristic, and the phase constant beta of the quasi-TEM waves changes slightly in a wide frequency band range, so that a fixed radiation wave beam can be obtained in a certain frequency band range; inversion signals are fed at the two ends of the leaky-wave structure so that the two wave beams can form a main wave beam, when the two wave beams deviate from the broadside to radiate by a certain angle, a wave beam with good radiation can still be formed, and therefore the bandwidth corresponding to the fixed radiation wave beam is further widened. On the basis, a plurality of radiation matching units are sequentially arranged on the metal strip in the length direction of the metal strip, so that the fixed-beam leaky-wave antenna has the characteristics that the angle of a radiation beam is kept unchanged in a relatively wide bandwidth, the gain is high, the efficiency is high and the side lobe is low.

The invention provides a leaky-wave antenna and a frequency-modulated continuous wave generation method based on the leaky-wave antenna, and relates to the field of millimeter-wave radar, and the method comprises the steps: constructing a space-time coding matrix, configuring a radiation unit state regulation and control beam direction in a space domain, modulating a radiation unit state switching rule in a time domain to generate a frequency-modulated continuous wave, and achieving space-time dual-domain regulation and control. And frequency-modulated continuous waves with controllable bandwidth are generated. The space-time coding leaky-wave antenna is formed by alternately arranging 1-bit radiation units in an upper row and a lower row, switching of radiation / non-radiation states is achieved by loading a synchronous bias PIN diode across an annular gap, a space-time coding matrix is constructed, the states of the radiation units are configured in a space domain to regulate and control the wave beam direction, and the space-time coding leaky-wave antenna is formed. Modulating the switching rule of the radiation unit in a time domain, and generating a frequency-modulated continuous wave; the radiation efficiency is improved by the alternative arrangement of the radiation units, the control difficulty and the hardware cost are reduced, multiple functions are integrated into a single device, and the problem of low integration level of the traditional separation architecture is solved.

The application provides an electrically-controlled beam scanning leaky-wave antenna and a communication device. The leaky-wave antenna comprises a gap waveguide including a strip-shaped ridge, the gap waveguide being used for transmitting electromagnetic waves in the form of a traveling wave, the strip-shaped ridge being arranged in the gap waveguide along a transmission direction of the electromagnetic waves; and a plurality of radiation units arranged on a side wall of the gap waveguide, each of the radiation units comprising a radiation slot and an electrically-controlled switch, the radiation slot being used for leaking electromagnetic waves in the gap waveguide to a free space to form a beam, and the electrically-controlled switch being used for controlling an operating state of the radiation slot to realize beam scanning. The leaky-wave antenna provided by the application can improve the beam tilting characteristics of the antenna and improve the communication quality of the antenna.

The application provides a leaky-wave antenna array based on a multimode substrate integrated waveguide coupler, relates to the technical fields of wireless communication and radar, and comprises a dielectric substrate, a multimode substrate integrated waveguide coupler and two leaky-wave antenna units. The multimode substrate integrated waveguide coupler is integrated on the dielectric substrate and is configured to excite modes and modes of the substrate integrated waveguide respectively in the same frequency range, generate even-mode signals with equal amplitude and in-phase and odd-mode signals with equal amplitude and opposite phase. The two leaky-wave antenna units are symmetrically arranged on the two sides of the upper surface metal layer of the dielectric substrate and are connected with two output ports of the multimode substrate integrated waveguide coupler respectively. The two leaky-wave antenna units are configured to radiate a wave beam and a difference wave beam in response to the even-mode signals and the odd-mode signals. The application solves the problem of low measurement accuracy of a traditional single-pulse antenna, has the technical effects of simplifying the design of a feed network, improving radiation performance and thus improving measurement accuracy.

The invention discloses an ultrahigh-scanning-rate leaky-wave antenna based on double-layer offset quasi-complementary SSPP. The antenna comprises a dielectric substrate, double-layer single-side offset quasi-complementary SSPP structures on the upper surface and the lower surface of the dielectric substrate, a double-layer mode conversion structure and a dielectric substrate top layer periodic modulation branch knot. Wherein the longitudinal symmetry axis of the dielectric substrate top layer single-side strip SSPP unit and the longitudinal symmetry axis of the dielectric substrate bottom layer single-side slot SSPP unit are relatively offset, and a double-layer single-side offset quasi-complementary SSPP unit is jointly formed; the double-layer mode conversion structure is composed of a trapezoidal gradual change structure on the top layer of the dielectric substrate and a periodic gradual change slotting structure on the bottom layer of the dielectric substrate; and the dielectric substrate top layer periodic modulation branch knot is formed by compounding a rectangular structure and a semicircular structure loaded at the tail end of the rectangular structure, and is positioned on the opposite side of the top layer single-side strip SSPP structure. The wide-angle scanning ultra-narrow band-pass filter has the advantages of wide-angle scanning, ultra-narrow working bandwidth, ultra-high beam scanning rate and open stop-band suppression, and has very high practical potential in the fields of radar, imaging and the like.

The present disclosure relates to the technical field of communications, and provides a leaky-wave antenna and an antenna system. The leaky-wave antenna comprises: a first dielectric substrate, a first metal layer, a dielectric functional layer, a second metal layer, and a second dielectric substrate. The first metal layer comprises a first transmission line and first radiation units; multiple first notches distributed at intervals are provided on a side edge, parallel to a length direction, on a first plasmon section of the first transmission line; and the multiple first radiation units and the first notches are located on the same side of the first transmission line. In the embodiments of the present disclosure, on the basis of the first plasmon section comprised in the first transmission line, the confinement capability of electromagnetic signals can be enhanced, and the radiation of the electromagnetic signals can be reduced, thereby ensuring the transmission efficiency of the electromagnetic signals, and achieving compact design of leaky-wave antennas. In addition, by radiating antenna signals outward from the first radiation units, high gain of the antenna signals can be ensured while maintaining high transmission efficiency in the first transmission line.

The invention discloses an electrically-controlled beam scanning leaky-wave antenna and communication equipment, belongs to the technical field of antennas, and is used for solving the problems that an existing antenna is complex in structure and the beam scanning angle is limited under a fixed frequency. The electrically controlled beam scanning leaky-wave antenna comprises a gap waveguide and a plurality of radiation units. The gap waveguide comprises a cover plate and a metal bottom plate which are oppositely arranged, and a ridge structure arranged on the upper surface of the metal bottom plate in the transmission direction of the electromagnetic waves, and the gap waveguide is used for transmitting the electromagnetic waves in a traveling wave mode; the plurality of radiation units are sequentially arranged on the cover plate along the extension direction of the ridge structure; each radiation unit comprises a radiation patch, two radiation slots and two electric control switches which are sequentially arranged from top to bottom, and the radiation slots and the electric control switches are distributed in a central symmetry manner relative to the radiation patch; and each electric control switch is used for controlling the working state of the corresponding radiation slot so as to regulate and control the radiation phase of the radiation unit and realize beam scanning.

The invention belongs to the field of antennas, and particularly relates to a topological leaky-wave antenna based on gyromagnetic photonic crystals. A single gyromagnetic YIG column is adopted to construct square primitive cells, an upper magnet layer and a lower magnet layer are assisted to provide a magnetic field, the primitive cells are adaptively and closely arranged into the array antenna, boundaries in all directions of a rated area are perfect electric conductor boundaries, and a slot array of a leaky wave area is formed in the boundary of an excitation source. According to the topological leaky-wave antenna, leaky-wave scanning regulation and control of the antenna can be carried out through adjustment of parameters such as a magnetic field, an antenna structure and frequency, and the topological leaky-wave antenna has the characteristic of multi-degree-of-freedom adjustment; the waveguide has the advantages that the structure is simple, the transverse emergent effect is good, the open-stop band phenomenon is overcome, impedance matching is overcome, no reflection signal exists, and waves in the waveguide can only be transmitted in a one-way mode. The problem that an existing leaky-wave antenna needs impedance matching and has an open stop band is effectively solved.

The invention discloses a full-airspace scanning terahertz leaky-wave antenna and a terahertz radio frequency system, the full-airspace scanning terahertz leaky-wave antenna comprises a feed part, an antenna main body part and an absorption part, and the feed part and the absorption part are connected with two ends of the antenna main body part; the back surface of the feed part is provided with a rectangular waveguide port, the antenna main body part comprises a top radiation layer, a middle transmission line layer and a bottom series feed network layer, the bottom series feed network layer is used for distributing energy among different antenna units, each of the feed part, the antenna main body part and the absorption part comprises ten layers, and each layer is made of copper. The top radiation layer comprises a ninth layer and a tenth layer, and the tenth layer is provided with a leaky-wave antenna array; the middle transmission line layer comprises a third layer to an eighth layer, and the seventh layer and the eighth layer are provided with SSPP transmission lines; the antenna can realize two-dimensional beam scanning of + / -30 degrees within the frequency band of 0.26-0.33 THz, and has high efficiency and a compact structure.

The invention belongs to the technical field of terahertz communication physical layer security, and particularly relates to a terahertz physical layer key generation method based on leaky-wave antenna space-spectrum coupling characteristics. According to the invention, the sensitivity of the effective antenna gain of the leaky-wave antenna to the frequency and the spatial propagation direction is utilized to make up for the defect of low eavesdropping channel doubtful degree caused by lack of small-scale fading in terahertz communication, and the conditional generative adversarial network is designed to accurately speculate the equivalent channel power gain. A physical layer key is generated based on the estimated channel power gain. According to the method, the channel power gain can be accurately estimated from the received signal strength with noise and auxiliary information, the reciprocity of an equivalent channel is enhanced, and the method has a lower key mismatch rate and a higher key generation rate; under the condition of different signal-to-noise ratios, good key generation performance can be kept.

This invention discloses a three-element leaky wave antenna array structure based on a dielectric ridge parallel plate waveguide, comprising: S1, designing a three-element array structure based on the coupling characteristics of the dielectric ridge parallel plate waveguide, wherein the two-port array antenna is fed by probes in parallel; S2, determining the slot design of the three elements according to the pattern product theorem and the relationship between slot size and leakage, thereby designing a scanning beam that meets the requirements of narrow beamwidth and high gain. This invention is a leaky wave antenna array structure with narrow beamwidth and high gain characteristics proposed to meet the requirements of high signal strength and strong anti-interference in long-distance point-to-point communication systems. This antenna can provide better directivity and higher communication quality, while ensuring that the antenna has the advantages of compact structure and small size, thus it can be applied to wireless power transmission systems such as satellite communication systems, radar systems, and the Internet of Things.

The invention discloses a leaky-wave antenna unit and a leaky-wave antenna array. The leaky-wave antenna unit comprises a driving patch, a microstrip feeder, a plurality of low-frequency leaky-wave patches, a plurality of high-frequency leaky-wave patches, a first dielectric plate, a second dielectric plate, a third dielectric plate, a metal reflection floor and a fourth dielectric plate, the multiple low-frequency leaky-wave patches and the multiple high-frequency leaky-wave patches are arranged on the upper surface of the first dielectric plate, the multiple high-frequency leaky-wave patches surround the outer sides of the multiple low-frequency leaky-wave patches, and the distance between every two adjacent high-frequency leaky-wave patches is equal; the driving patch is located between the first dielectric plate and the second dielectric plate, a through hole is formed in the metal reflection floor, the microstrip feeder line is arranged below the fourth dielectric plate, the connecting end of the microstrip feeder line is connected with the feed interface, and the projection of the through hole in the direction perpendicular to the metal reflection floor intersects with the microstrip feeder line. According to the scheme, the use efficiency of the leaky-wave antenna can be improved.

The application discloses a variable-beam control method of a variable capacitance diode-based element grating leaky-wave antenna, and comprises the following steps: S1, researching and analyzing an ultra-grating beam conversion mechanism; researching the mechanism of a planar ultra-grating under anisotropic, uniform and continuous periodic boundary conditions; S2, according to the ultra-grating, researching a transmission mode and optimization design of a Floquet-Bloch theorem; researching an FB mode, and eliminating the bad FB mode by designing a tool for ultra-grating parameters; S3, analyzing and designing the ultra-grating leaky-wave antenna; researching the analytical field and current of the synthesized ultra-grating in the framework of the leaky-wave antenna, so as to customize the performance of phase, beam shape and polarization; S4, designing and analyzing an electrically-tuned beam control ultra-grating leaky-wave antenna; the application adopts the variable-beam control method of the variable capacitance diode-based element grating leaky-wave antenna, adopts a simple structure of a tunable material to tune an efficient structure platform, and lays a road for a new generation of efficient special gratings.

This invention provides an artificial surface plasmon full-space beam scanning leaky antenna, comprising a dielectric substrate. The upper and lower surfaces of the dielectric substrate form a top layer and a bottom layer, respectively. The top layer of the dielectric substrate has a balun structure, an artificial surface plasmon strip group, and several metal stubs. Balun structures are symmetrically arranged at both ends of the artificial surface plasmon strip group. Several metal stubs are periodically arranged and symmetrically arranged on the upper and lower sides of the artificial surface plasmon strip group. The artificial surface plasmon strip group includes a pair of slidingly symmetrical artificial surface plasmon strips. This invention enables continuous scanning of the main beam from back-firing to front-firing, possessing full-space beam scanning capability. It has advantages such as small bandwidth occupation, high radiation efficiency, high directivity, high gain, low profile, and relatively small overall size, and can be applied in wireless communication fields such as automotive radar.

To provide an irreversible transmission line having a two-dimensional structure and capable of uniformly distributing an electromagnetic field in a two-dimensional plane.SOLUTION: An irreversible transmission line includes first and second transmission lines that are orthogonal to each other by configuring basic cells having two transmission line portions that are orthogonal to each other and have parallel branch circuits so as to be juxtaposed and cascaded in orthogonal first and second directions. The transmission line part at a position other than an intersection point of the first and second transmission lines is formed of a material magnetized by spontaneous magnetization or the like so as to have gyro anisotropy by being magnetized in a different direction with respect to a propagation direction of a microwave. In a dispersion curve indicating a relationship between an operating frequency of a microwave signal input to each transmission line and a propagation constant of each transmission line, at least one of the parallel branch circuits of each transmission line is configured such that a wave component propagating along each of the parallel branch circuits in a longitudinal direction of each transmission line has an irreversible characteristic and is asymmetrical with respect to the transmission line portion.SELECTED DRAWING: Figure 5

The application relates to the field of wireless communication and sensing technology, and particularly discloses a two-dimensional antenna array multi-beam scanning method based on holographic amplitude weighting, which comprises the following steps: determining the position information of each radiation unit in the two-dimensional antenna array, including calculating the unit spacing and arrangement mode; generating the amplitude weighting value of each radiation unit according to the target wave direction; using the two-dimensional multi-beam holographic amplitude weighting technology, the amplitude weighting value of the radiation unit is determined through the two-dimensional multi-beam holographic amplitude weighting technology; generating the corresponding binary discretization coding sequence based on the amplitude weighting value to control the excitation amplitude of each radiation unit; designing a Ka-band two-dimensional holographic beam scanning leaky-wave antenna square array based on liquid crystals, and the radiation pattern of the two-dimensional antenna array is regulated and controlled through the coding sequence to realize multi-beam scanning.

This invention provides an indoor positioning system and method. A WiFi signal is generated via a WiFi access point. A first leaky-wave antenna converts the received WiFi signal into a first circularly polarized signal and propagates it to a target receiver. A second leaky-wave antenna converts the received WiFi signal into a second circularly polarized signal and propagates it to the target receiver. The second circularly polarized signal is orthogonal to the first circularly polarized signal. The target receiver obtains the target's indoor location information based on the first and second circularly polarized signals. This method eliminates the need for the target to switch between multiple WiFi access points, is less affected by WiFi signal quality, has strong applicability, and provides more accurate positioning.