Reflective plasma antenna

Abstract

FIELD: antenna technology.SUBSTANCE: invention can be used for transmitting and receiving electromagnetic signals in a wide range of wavelengths, including in satellite communication systems. In a reflective plasma antenna, an optimal reflector shape for transmitting radio signals of the required spectral range is created by illuminating a specially manufactured reflector based on a layered structure of dielectric surfaces comprising isolated semiconductor sections with a laser source. The electrical resistance of semiconductor sections under laser irradiation decreases by more than an order of magnitude, whereas the reflectivity in the operating range of the radio transmitter, on the contrary, increases, which makes it possible to form the required geometry of the reflective surface of the reflector.EFFECT: increased reliability, improved electromagnetic compatibility parameters, the ability to quickly control the characteristics of the antenna device, simplified design and the addition of new functional capabilities (in particular, the addition of the ability to optically control the antenna parameters).1 cl, 2 dwg

Description

[0001] Technical field

[0002] The invention relates to the field of antenna technology and can be used for emitting electromagnetic radiation in the radio and microwave ranges.

[0003] Technology Level

[0004] A plasma antenna (analog) is known in the art, in which the radiating element is an ionized air column created by a laser beam and similar to a radiating metal rod. The laser antenna consists of a laser, which is designed to generate the laser beam, a focusing device, and a circuit for connecting the signal source to the base of the ionized air column (US Patent No. 3,404,403, 343-700, 1968).

[0005] The disadvantage of the analogue is the high level of energy consumption for the formation and maintenance of a plasma channel with high conductivity in the air, the low functionality of the device, due to the known difficulties of obtaining plasma channels with high conductivity in atmospheric air, as well as the impossibility of quickly adjusting the resistance of this plasma formation.

[0006] A plasma antenna is known, which is a radiating element in the form of a plasma formation, which is located inside a dielectric tube containing a plasma-forming gas at reduced pressure. (RU Patent No. 2014106756, H01Q 13 / 00, 2015).

[0007] The disadvantage of the analogue is the high level of energy costs for the creation and maintenance of gas-discharge plasma, the impossibility of significantly increasing the plasma concentration under conditions of low gas pressure, and the low overall functionality of the device, which contains a gas-discharge tube and a high-voltage power supply for obtaining gas-discharge plasma.

[0008] A plasma transmitting and receiving antenna (analog) is known, in which the radiating element is a gas-discharge plasma generated by a plasma generator. The plasma transmitting and receiving antenna consists of a plasma generator with an electrode system, which is designed to create plasma formations, a control system, decoupling and switching of information signals, and a power supply system (RU Patent No. 2255394, H01Q 1 / 00, 2005).

[0009] The disadvantage of the analogue is the high level of energy consumption for the creation of a plasma formation, the low functionality of the device, due to the known difficulties in obtaining plasma formations with stable properties, as well as the need to use high-voltage power systems, which worsens the electromagnetic compatibility of such a device.

[0010] A photoconductive antenna is known (patent DE 102006010297 B3, published on 19.07.2007), equipped with a laser element "Photoconductive antenna for laser pulses or for high-frequency electromagnetic radiation with a laser pulse"), in which, by irradiating semiconductor elements with a laser, frequency tuning was achieved in a certain, fairly narrow frequency range corresponding to the terahertz range of the spectrum.

[0011] A disadvantage of this analog is the narrow spectral range for which the antenna is designed. The semiconductors irradiated by the laser pulse are widely used in many other photoconductive laser antennas for the terahertz frequency range. However, the designs described therein are not scalable to frequencies below 100 MHz. As follows from the description of such antennas, the short wavelength and high operating frequencies determine the significant influence of capacitive coupling, as well as the ability of the photoplasma in the semiconductor to act as an antenna. At operating frequencies below 100 MHz or even 10 GHz, terahertz antenna designs become inoperable.

[0012] A prior art LASER PLASMA ANTENNA [RU 2742380, published 05.02.2021] is known, comprising a radiating element in the form of a plasma formation formed in a set of solid-state waveguide semiconductor structures having electrical contact with an electromagnetic signal transceiver, and additionally connected via fiber-optic channels through an optical distribution device to a light source, the quantum energy of which is sufficient to create photoplasma due to the internal photoelectric effect in the semiconductor structure. The technical result of the invention is to improve the parameters of electromagnetic compatibility, simplify the design, and add new functionality.The technical result is achieved due to the fact that in the laser plasma antenna, instead of gas-discharge plasma, a semiconductor plasma is used, formed in a special waveguide semiconductor structure using a laser or LED radiation source, by adjusting the power of which the resistance of the semiconductor structure can be reduced by several orders of magnitude and, conversely, when the light source is turned off, it will go into a weakly conducting state (kOhm and higher), and by connecting the light source to the waveguide structures through an optical distribution device, it is possible to switch between waveguide semiconductor antennas with different configurations.

[0013] The disadvantage of the analog is the limited ability to reconfigure the antenna in conditions where it is necessary to increase the antenna radiation power, since to ensure operation in different frequency ranges, a whole set of corresponding lengths of sections of semiconductor structures is required, which will heat up strongly during antenna operation, which leads to an increase in the inertia in changing the conductivity of the semiconductor structure and does not allow dynamic control of changes in antenna parameters.

[0014] A PLASMA ANTENNA is known from the prior art [RU 2736811, published 20.11.2020], comprising a tube, a metal contact element for connecting the end of the tube to a receiving and transmitting device, as well as a radiation source located at the end of the tube with the possibility of directional transmission of light radiation into the tube, which is made in cross-section -shaped in the form of a dielectric capillary, the inner walls of which are coated with a semiconductor, wherein the radiation source is configured to generate radiation with a quantum energy exceeding the band gap energy of the semiconductor. The radiation source is a laser or LED source or an optical waveguide connected to such an external source, and the metal contact element is configured to connect to the ends of additional tubes arranged to provide directed radiation transmission from the radiation source into these tubes. The technical result consists in expanding the arsenal of technical means used as transmitting and receiving antennas.

[0015] The disadvantage of the analogue is the impossibility in the current antenna configuration of irradiating different sections of the semiconductor with a radiation source, that is, the impossibility of dynamically changing the antenna parameters.

[0016] A reconfigurable antenna [US 2002039083, published 04.04.2002] is known, comprising a plurality of surface PIN devices arranged in a grid, each of the SPIN devices can be individually activated or deactivated. When the SPIN device is activated, carriers are introduced onto its surface in such a way that plasma is formed within the internal region of the device. The plasma can have sufficient conductivity to create conductive or metallic characteristics on the surface of the device. Various SPIN devices can be activated for electronically drawing a conductive pattern on a substrate supporting the PIN devices. The technical result: due to selective activation of the SPIN devices on the substrate, it is possible to create various radiation patterns of surface antennas, including dipoles, crossed dipoles, loop antennas, Yagi-Uda antennas, log-periodic antennas, etc.Additionally, the SPIN device's grid can be selectively activated to create holographic antennas.

[0017] The main technical problems of the analog are: low antenna surface efficiency due to the small area of ​​the plasma regions created on it compared to laser LEDs; low maintainability due to the increased complexity of manufacturing the circuit connecting the printed circuit board, substrate, and bias pins, which also reduces the reliability of the design; the lack of a self-diagnostic system for the bias pins and lead electrodes, which does not allow for the timely detection of emerging faults and, thus, reduces the reliability of the antenna design.

[0018] The closest in technical essence and achievable technical result (prototype) is known as a PLASMA ANTENNA WITH CONTROLLED PARAMETERS [RU 2786762 C1, publ. 26.12.2022] comprising a housing formed by side walls, a base and a cover, inside the antenna housing along its length parallel to the base a reflector is mounted, made in the form of a plate of magnetically permeable material with a deposited layer of semiconductor, a light source is mounted to the base behind the reflector, made in the form of a matrix of LEDs of a narrowly directed light beam, each of the LEDs is connected to a microcontroller, the microcontrollers are connected to individual Ethernet modules united by a common bus, on one of the side walls of the antenna housing differential pressure pipes equipped with pressure sensors are mounted, a slot emitter made in the form of a waveguide is mounted to the side wall of the housing opposite the cover of the housing using a bracket,wherein the said bracket is provided with drives for changing the angle of inclination of the slot radiator relative to the plane of the reflector, the slot radiator contains a matrix of LEDs of a narrowly directed light beam, each of the LEDs is connected to a microcontroller mounted inside the waveguide in a shielded box, the microcontrollers are connected to individual Ethernet modules united by a common bus, at the end of the slot radiator facing the antenna body, a reflector of the slot radiator is mounted, made in the form of a plate of semiconductor.

[0019] The disadvantage of the prototype is the complexity of the design, which requires multiple light sources and special control of each individual LED. Illumination of a solid semiconductor does not allow the formation of a dense plasma structure with a high plasma concentration due to the diffusion of charge carriers in the semiconductor material and rapid spreading, which requires colossal light power.

[0020] Essence of the invention

[0021] The technical objective of this invention is to implement the possibility of optical control of the antenna radiation pattern with a high power of the radio-emitting source, which results in low power consumption of the radiation pattern control systems and high resistance of the antenna device to electromagnetic interference, which makes it promising for use on space communication satellites.

[0022] The technical result is achieved by using a plasma reflector to control the antenna's radiation pattern. This reflector is formed on a dielectric surface by creating a semiconductor plasma that reflects radio waves from the emitter at precisely defined locations on the dielectric surface. The ability to create a custom-shaped reflective structure is achieved by using a special four-layer dielectric surface containing dielectric-insulated sections of a semiconductor material with high electrical resistance in its initial state, which decreases when irradiated with laser radiation with photon energies exceeding the bandgap energy. Irradiating the semiconductor with laser radiation generates an electron-hole plasma whose concentration exceeds the critical value for the emitter's frequency.The main feature of the arrangement of semiconductor sections on a dielectric surface is that any section can be exposed to laser radiation, forming a semiconductor plasma in it independently of neighboring sections, i.e., the semiconductor sections in the layers closest to the laser element do not shield other semiconductor sections from laser radiation, and dielectric insulation of the semiconductor sections is necessary to prevent the spread of charge carriers.

[0023] List of figures

[0024] The essence of the invention is explained by the figures: Fig. 1 and Fig. 2, which show the general diagram of a reflective plasma antenna and schematically an example of the arrangement of semiconductor sections on 4 dielectric surfaces located strictly one after another, which make it possible, when exposed to laser radiation on the semiconductor sections, to form a plasma mirror of arbitrary shape with a spatial resolution determined by the transverse size of the semiconductor section.

[0025] In Fig. 1 the following is indicated: 1 - radio transmitting device, 2 - laser distribution device, 3 - reflector on which a plasma mirror is formed.

[0026] In Fig. 2 the following are indicated: 4, 5, 6, 7 - four dielectric layers of the reflector containing semiconductor sections are schematically shown, 8 - the shaded pixels show the location of the semiconductor section, the conductivity of which increases with increasing intensity of laser irradiation, 9 - the dielectric surface which contains semiconductor sections (8).

[0027] Implementation of the invention

[0028] The device consists of a radio emitter 1 and a plasma reflector 3, which forms the antenna's radiation pattern (Fig. 1). The reflective surface shape, necessary for controlling the antenna's radiation pattern, is formed by a semiconductor plasma with a concentration above the critical value for the antenna's operating range. This plasma is generated by illuminating semiconductor sections deposited on the reflector's dielectric surface with laser radiation. Laser radiation is delivered to the reflector, which is formed on a dielectric surface consisting of at least four layers containing isolated semiconductor sections, directly in the free space of the laser distribution device, which includes the laser element and the light beam shaping system.The laser distributor projects a light pattern onto the reflector that matches the shape of the plasma mirror required to create the required antenna pattern.

[0029] The device operates as follows: a control signal arriving at the laser distribution device generates laser pulses and a spatial structure of the light beam, which is projected onto a reflector, forming a plasma mirror of the required geometry. The shape of this plasma mirror can be quickly changed by selectively irradiating semiconductor regions on the reflector's surface. To optimize the working space and enable optical control of the reflective plasma antenna's radiation pattern over a wide range of angles, the dielectric surface with the semiconductor regions can be located not on a flat surface, but on a radio-transparent spherical, parabolic, or cylindrical surface. In this case, the radiation source and other equipment will be housed within the dielectric sphere or cylinder.The reflector's reflective surface is reshaped electronically without mechanical movement of the antenna components, significantly increasing the overall reliability and service life of the proposed antenna device. The reflector's materials and weight are low, and its manufacturing technology is well-established. Currently, creating a laser distribution device capable of quickly projecting beams of arbitrary shape onto a reflector is straightforward.

Claims

A reflective plasma antenna equipped with a laser element with a light beam forming system, characterized in that the formation of the antenna radiation pattern from the radio emission source is carried out by a reflector, which is formed on a dielectric surface having a layered structure and consisting of at least 4 dielectric layers, each of which contains sections of a semiconductor material that do not have a common boundary with each other, and in projection onto a plane parallel to this dielectric surface, the sections of the semiconductor material create a continuous surface without breaks, while the laser element, with the help of the beam forming system, has the ability to illuminate any section of the semiconductor material with radiation, creating a sufficiently dense electron-hole plasma in the volume of the semiconductor section, due to which the illuminated sections of the semiconductor form a reflective structure in the region of the radio frequency spectrum,which is directed from the radio source.,

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