48 results about "Feed horn" patented technology

The invention discloses a 2-bit multi-polarization reconfigurable electric control metasurface antenna which comprises a linear polarization feed source horn and a reflection type metasurface. The reflective metasurface comprises a plurality of metasurface units arranged periodically, and each metasurface unit comprises a first metal layer, a first dielectric plate, a second metal layer, a prepreg layer, a third metal layer, a second dielectric plate and a fourth metal layer which are sequentially and coaxially stacked from top to bottom. And two pairs of p-i-n diodes are integrated on each metasurface unit and are used for regulating and controlling linearly polarized waves from the feed source. According to the metasurface antenna, the radiation capacity of dual linear polarization and dual circular polarization is achieved through the single linear polarization feed source and the single reflection type metasurface at the same time, the beam scanning capacity of + / -60 degrees is achieved, and the aperture efficiency is high. In addition, a direct-current control circuit for controlling a p-i-n diode switch is designed on the back surface of the reflective metasurface, so that the integration level of the metasurface system is greatly improved. The metasurface antenna has the advantages of being simple in structure, large in polarization number, low in structural complexity and high in integration degree.

The invention relates to a dual-channel broadband millimeter wave circularly polarized folded array antenna for generating a Bessel OAM wave beam. The dual-channel broadband millimeter wave circularly polarized folded array antenna comprises a plane transmission array, a plane reflection array, a first feed horn and a second feed horn, the plane reflection array is provided with two hollow areas which are respectively used for placing the two feed horns, and the two feed horns are symmetrically placed at an equivalent focal plane of the plane reflection array, rotate for 17.2 degrees along an X axis and are used for radiating x-polarized waves; the plane reflection array is arranged right below the plane transmission array; the plane reflection array is composed of polarization conversion units arranged in an m * m array. The plane transmission array is composed of linear polarization-to-circular polarization units arranged in an n * n array. The polarization conversion unit is used for receiving the x-polarized wave, converting the x-polarized wave into a y-polarized wave and reflecting the y-polarized wave back to the plane transmission array; and the linear polarization to circular pole is used for converting the y polarization wave into a left-hand circular polarization wave and providing required phase compensation for the realization of an OAM vortex wave beam. The method has the advantages of wide bandwidth, low profile, dual-channel multiplexing, non-divergence of OAM beams and the like.

The invention particularly relates to an antenna for realizing quasi-diffraction-free beamforming and scanning, which comprises a phase shift metasurface and a feed horn antenna, and is characterized in that the feed horn antenna directly faces the center of the phase shift metasurface; the phase shift metasurface is of a double-layer dielectric substrate structure with an electromagnetic wave phase shift function, the whole phase shift metasurface is composed of a plurality of phase shift units arranged periodically, and the structure of each phase shift unit comprises an upper layer metal patch, a middle layer metal patch, a lower layer metal patch, an upper layer dielectric substrate and a lower layer dielectric substrate; the phase shift unit is equivalent to a low-pass filtering phase shifter with a phase shift effect, insertion phase shift at different angles can be realized at any position of the phase shift metasurface by setting the sizes of the three layers of metal patches in each phase shift unit on the phase shift metasurface, and then the insertion phase shift at different angles can be realized under the irradiation of the feed horn antenna. And generating phase distribution meeting the ideal phasor shift quantity of the quasi-non-diffraction beam on the outlet surface of the phase shift metasurface so as to generate the quasi-non-diffraction beam. According to the invention, the problem that the starting point of the non-diffraction region of the quasi-non-diffraction wave beam is uncontrollable is solved.

The present invention discloses a single-layer broadband reflectarray antenna with independent control of dual-linear polarization. The present invention realizes the x-polarization working state and the y-polarization working state of the reflectarray antenna by rotating the horn antenna 0° and 90° relative to the planar reflectarray; the planar reflectarray includes a plurality of reflective units, each of which includes a dielectric layer, a metal reflective layer and a metal backplane layer; the metal reflective layer includes a metal ring and a cross-shaped metal patch. The present invention realizes independent reflection responses in two directions of the reflective unit through a single degree of freedom, and relies on rotating the feed horn antenna to change the polarization working state of the array antenna. The present invention adopts a single-layer structure without air gaps, achieving low profile, lightweight, simple manufacturing and low cost, and adopts a continuous phase adjustable method. It is the first time to propose a single-layer broadband reflectarray antenna with independent dual-linear polarization and continuous phase adjustment, realizing a lightweight single-layer design while ensuring high aperture efficiency and broadband.

The application relates to a large-diameter high-power pseudo-Bessel beam generation method and a generation device, and belongs to the technical field of communication. The method comprises the following steps: S100, an electromagnetic beam output by a feed horn is propagated to a first reflecting surface, and a target pseudo-Bessel beam is reversely propagated to a second reflecting surface; S200, the electromagnetic beam is propagated to the second reflecting surface through the first reflecting surface, a phase difference on the second reflecting surface is obtained, and a deformation variable of the second reflecting surface is updated; S300, the target pseudo-Bessel beam is propagated to the first reflecting surface through the second reflecting surface, a phase difference on the first reflecting surface is obtained, and a deformation variable of the first reflecting surface is updated; and S400, steps S100 to S300 are repeated until the relative field distribution of the output electromagnetic beam and the target pseudo-Bessel beam reaches a stable state, and a large-diameter high-power pseudo-Bessel beam is obtained. The application can solve the technical problems of existing media loss and limited power capacity.

The present invention relates to the technical field of satellite antennas, and discloses a foldable satellite antenna structure, wherein a piston seat is disposed in a storage cylinder and is movable along the axial direction of the storage cylinder. A driving device is connected to the piston seat and drives the piston seat to move along the axial direction of the storage cylinder. A feed horn is disposed on top of the piston seat, a secondary reflector platform is slidably mounted on the feed horn, the secondary reflector is located above the feed horn, and is connected to the secondary reflector platform via a connecting bracket. The top end of a spring is connected to the bottom of the secondary reflector platform, and the bottom end of the spring is connected to the top of the piston seat. A plurality of foldable ribs are provided, the foldable ribs including a root rib and a top rib. The first end of the root rib is hinged to the side of the piston seat via a first hinge, and the second end of the root rib is hinged to the first end of the top rib via a second hinge. The first hinge and the second hinge are respectively provided with elastic components. The present invention has the characteristics of a small folded size, a large unfolded size, and a lightweight structure.

The invention provides a near-field feed low-complexity reconfigurable antenna system, which belongs to the technical field of millimeter wave communication antennas and comprises a 1-bit phased array, a waveguide feed horn array and an air gap between the 1-bit phased array and the waveguide feed horn array. The 1-bit unit is composed of two magnetoelectric dipoles, and two diodes are integrated in the receiving unit to achieve 1-bit phase control. According to the 1-bit reconfigurable magnetoelectric dipole phased array disclosed by the invention, one horn mouth surface is used as a near-field feed source of the 2 * 2 magnetoelectric dipole sub-array, so that not only is the uniformity of aperture irradiation ensured through near-field coupling, but also the number of required phase shifters is reduced, and the excitation of the 1-bit reconfigurable magnetoelectric dipole phased array is conveniently realized. The waveguide phase shifter is directly integrated in the horn array antenna, by means of the working phase range wide enough, the phase shifter can effectively achieve phase distribution needed by array near-field feed, and mirror lobes in scanning beams are successfully suppressed. The reconfigurable array antenna is high in aperture efficiency, low in profile and simple in structure, and has the broadband scanning capability.

The invention provides an integrated reconfigurable filtering honeycomb super-medium reflective array, which belongs to the field of antennae and comprises a multi-feed horn, a reflective array ground plane and a first transmission network arranged on the surface of one side of the reflective array ground plane in a matrix mode. Reconfigurable filters corresponding to the positions of the first transmission networks are arranged on the surface of the other side of the reflection ground plane, and each first transmission network comprises a honeycomb-shaped transmitting unit T and a honeycomb-shaped receiving unit R. The multi-feed-source horn transmits electromagnetic wave signals to the air. Each receiving unit R receives a signal and transmits the signal to the transmitting unit T through the corresponding reconfigurable filter, each transmitting unit T transmits wave beams outwards, the transmitting unit T can receive the wave beams transmitted by different receiving units R, and performance parameters are set and reflected frequency characteristics are adjusted by adjusting the reconfigurable filters; the invention further provides a honeycomb super-medium transmission array integrated with reconfigurable filtering. The invention also provides a transflective array. And the frequency selectivity and the out-of-band rejection capability of the antenna are improved.

The application discloses a kind of phase electromagnetic metasurface design methods based on two-phase method, mainly solve the problem of electromagnetic metasurface structure complexity when existing technology electromagnetic metasurface is simultaneously regulated in amplitude phase.It is implementation scheme: initialization electromagnetic metasurface parameter;Electromagnetic metasurface unit required by two-phase method is calculated phase matrix;Design the electromagnetic metasurface unit including metal grating layer, two layers of dielectric layer and metal patch, and draw the phase table of the electromagnetic metasurface unit;According to the required phase of each unit of electromagnetic metasurface and the phase table of electromagnetic metasurface unit, the state of each unit of electromagnetic metasurface is adjusted to obtain adjusted electromagnetic metasurface;Feed horn is placed above adjusted electromagnetic metasurface, and radio frequency signal is added to feed horn, to generate required beam, complete phase electromagnetic metasurface design.The application can reduce the complexity of electromagnetic metasurface structure, improve the beam design capability of electromagnetic metasurface, and can be used for wireless transmission, communication system.

The utility model discloses a kind of microwave communication is used to feed source horn prevents bird device, including feed source horn, the top end of the feed source horn is integrally connected with drive box, the drive box is circular ring structure, drive box inside is fixedly connected with sliding block, sliding block top is provided with slide rail, the slide rail is circular ring structure, slide rail bottom is inserted with sliding block, sliding block and slide rail structure are matched, slide rail top is fixedly connected with driving rack, drive box top is provided with annular opening, the annular opening inside is slidably connected with mounting seat, mounting seat top is threadedly connected with prevent main spine, prevent main spine outer wall is fixedly connected with prevent small spine, mounting seat bottom is connected with second motor, second motor bottom is fixedly connected with driving rack, driving rack one side is engagedly connected with driving gear. The device can realize the automatic driving of bird, avoid the habitat of bird on feed source horn, thereby avoid feed source horn to be damaged by bird, prolong the service life of feed source horn.

The invention discloses an SIW transmission array antenna fusing multiple phase modulation modes, and belongs to the technical field of transmission array antennas. According to the antenna, antenna units form an array according to a period, and a feed source horn is arranged at the bottom of the antenna unit array. The antenna unit comprises two layers of linear polarization metasurfaces which are arranged up and down and three layers of SIW phase delay lines in the middle. According to the multiple phase modulation modes, the transmission characteristics of the SIW are utilized, the positions of metal through holes corresponding to SIW delay lines are changed, and then the length or the width of the SIW structure is changed, or the length and the width of the SIW structure are changed at the same time, so that the transmission phase of the SIW is changed, and finally the transmission phase of the transmission array unit is changed. Simulation proves that the SIW transmission array antenna provided by the invention can realize high gain and wide bandwidth.

The application discloses a feed horn for radio astronomy, which comprises a first ridge and a second ridge, the first ridge and the second ridge are cross arranged; a reflection plate is arranged at the bottom of the first ridge and the second ridge, used for positioning the first ridge and the second ridge, and reflecting back radiation; a loading medium rod is arranged at the center upper part of the cross of the first ridge and the second ridge; a support plate is arranged at the top of the first ridge and the second ridge, used for mounting the loading medium rod, and further fixing the first ridge and the second ridge. The matching structure of the specially designed ridge, the reflection plate, the loading medium rod and the support plate makes the feed horn realize higher performance in a wider frequency band. The coaxial feed is adopted, which has the advantages of simple structure, low cost, small size, light weight and easy impedance matching, and meets the needs of wide frequency band radio astronomy scientific observation of 2-16GHz.

The application provides a kind of transmission RIS transceiver downlink multi-stream communication system and method, comprising: transmission RIS transceiver module: including intelligent controller and transmission RIS panel;Intelligent controller generates corresponding control signal, changes the phase of transmission wave in RIS unit by control line, sends to user module;Loudspeaker antenna module: the information of intelligent controller module is loaded into the carrier of emission and sent to user module, and the information of transmission RIS transceiver module is loaded into the carrier of emission and radiated;User module: after receiving the signal sent by loudspeaker antenna module, harmonic extraction, symbol recovery and demodulation operation are carried out.The architecture proposed in the application can realize multi-stream communication only by equipping a radio frequency chain of feed horn antenna, and is a more low-power and low-cost solution.The architecture proposed in the application considers that each transmission unit is limited by its transmission capacity, and is more novel.

The application discloses a broadband polarization-insensitive 1-bit electrically-controlled programmable metasurface antenna, which comprises an electrically-controlled programmable metasurface and a feed horn, and the electrically-controlled programmable metasurface comprises M*N periodically arranged metasurface units, the unit comprises, from top to bottom, a metal layer one, a high-frequency dielectric substrate one, a metal layer two, a prepreg layer, a metal layer three, a high-frequency dielectric substrate two and a metal layer four, which are coaxially stacked in sequence; a metalized through hole is arranged at the center of the metasurface unit, the metalized through hole vertically penetrates through the high-frequency dielectric substrates and the prepreg layer and is connected with all the metal layers except the metal layer two; metalized blind holes are arranged around the metasurface unit, the metalized blind holes vertically penetrate through the high-frequency dielectric substrate one and are connected with the metal layer one and the metal layer two; four parallel PIN diodes are arranged on the metal layer one; the metasurface antenna has the characteristics of wide frequency band, full polarization compatibility, high polarization isolation and simple structure, and is suitable for satellite communication and 5 / 6G mobile communication.

A dual feed slot-based circularly polarized wideband ultra high frequency (UHF) antenna for a cubic shaped satellite (Cube-Sat) is described. The UHF antenna includes a circuit board, a metallic layer, a hexagonal meandered slot, a capacitor, a first feed horn, and a second feed horn. The circuit board has a front side and a back side separated by a dielectric material. The metallic layer covers the back side of the circuit board. The hexagonal meandered slot symmetrically includes six legs of equal length and six vertexes. The capacitor is switchably connected to the metallic layer. The first feed horn is connected by a first feed line to a first edge of the front side of the circuit board. The second feed horn is connected by a second feed line to a second edge of the front side of the circuit board.

The application discloses a multi-band reconfigurable reflectarray antenna, which comprises a feed horn and a reflectarray surface, and the reflectarray surface comprises a plurality of periodically and equidistantly arranged reflectarray units; the reflectarray unit comprises a dielectric plate, a radiation structure, a phase-shifting device and a control network; the radiation structure is a ring-shaped slot structure; two phase-shifting devices are mirror-installed on the radiation structure, and the on-off state of the phase-shifting devices is controlled by the control network to realize polarization conversion function and 1-bit phase control. The unit can work in multiple modes, thereby realizing multi-band reconfiguration. In particular, the unit can work in a first mode, a second mode and a third mode, and the corresponding frequencies are approximately one frequency, two frequencies and three frequencies. The application can realize dynamic scanning of multiple frequency bands by using the same aperture, and has wide application prospects in many fields such as satellite communication and mobile communication.

A dual feed slot-based circularly polarized wideband ultra high frequency (UHF) antenna for a cubic shaped satellite (Cube-Sat) is described. The UHF antenna includes a circuit board, a metallic layer, a hexagonal meandered slot, a capacitor, a first feed horn, and a second feed horn. The circuit board has a front side and a back side separated by a dielectric material. The metallic layer covers the back side of the circuit board. The hexagonal meandered slot symmetrically includes six legs of equal length and six vertexes. The capacitor is switchably connected to the metallic layer. The first feed horn is connected by a first feed line to a first edge of the front side of the circuit board. The second feed horn is connected by a second feed line to a second edge of the front side of the circuit board.

The utility model relates to a microstrip feed horn antenna, belongs to the technical field of antennas, and solves the technical problem that the gain and directivity of a conventional microstrip feed antenna are difficult to optimize and adjust according to actual requirements. The microstrip feed horn antenna comprises a horn cavity, a feed waveguide cavity and a feed printed board, the horn cavity is arranged on the feed waveguide cavity, the feed waveguide cavity bears the feed printed board, the distance between the feed printed board and the bottom of the feed waveguide cavity can be adjusted, the feed printed board comprises a first patch and a second patch which are connected with each other, and the first patch and the second patch are connected with each other. The first patch is connected to the feed network to realize feed, and the second patch is used for realizing impedance matching of the antenna; by adopting the technical scheme that the distance between the feed printed board and the bottom of the feed waveguide cavity can be adjusted, the distance between the first patch and the bottom of the feed waveguide cavity is also adjusted, so that the gain and directivity of the antenna can be optimized and adjusted according to actual requirements in the actual operation process.

The present application relates to a reflector antenna repointing device and a reflector antenna, the reflector antenna repointing device comprising: a microwave lens receiving an input field and providing an output field; a mounting structure connecting the microwave lens to the reflector antenna and mounting the microwave lens above a feed horn; and an alignment feature at the mounting structure, the alignment feature being configured for setting a position and orientation of the microwave lens relative to the reflector antenna, the alignment feature defining a lateral shift of the output field relative to the input field perpendicular to an axis of the reflector; the reflector antenna repointing device being configured to repoint the input field from an old satellite to a new target satellite without manual fine tuning.

The invention discloses a wide-angle scanning transmission array antenna based on an inclined beam unit. The wide-angle scanning transmission array antenna comprises a transmission array plane and a feed source horn which is arranged opposite to the transmission array plane and is adjustable in position. The transmission array surface comprises a plurality of array surface units, each array surface unit comprises a transmitting unit and a receiving unit, the transmitting units and the receiving units are connected through connecting metal through holes and share the same metal floor, and two rows of metal through holes which are arranged in a staggered mode are formed between the transmitting units and the metal floor so that the transmitting units can emit inclined wave beams. Phase regulation and control are carried out on the transmission array plane through a bifocus phase compensation method, and the bifocus phase compensation method comprises the steps that phase compensation values are calculated at the two virtual focuses respectively, and the average value is taken to serve as a compensation phase needed by an array plane unit. According to the invention, the emission unit with the inclined wave beam is adopted to regulate and control the amplitude of the emitted wave, and a bifocus phase compensation method is adopted, so that the phase error in the scanning process can be greatly reduced, and the scanning angle range is further expanded.

A dual feed slot-based circularly polarized wideband ultra high frequency (UHF) antenna for a cubic shaped satellite (Cube-Sat) is described. The UHF antenna includes a circuit board, a metallic layer, a hexagonal meandered slot, a capacitor, a first feed horn, and a second feed horn. The circuit board has a front side and a back side separated by a dielectric material. The metallic layer covers the back side of the circuit board. The hexagonal meandered slot symmetrically includes six legs of equal length and six vertexes. The capacitor is switchably connected to the metallic layer. The first feed horn is connected by a first feed line to a first edge of the front side of the circuit board. The second feed horn is connected by a second feed line to a second edge of the front side of the circuit board.

The application relates to the field of communication technology and discloses a high-gain medium vortex antenna, which comprises a feed horn antenna and a medium vortex lens; the feed horn antenna is used for generating a spherical wave; the hyperboloid of the feed horn antenna and the medium vortex lens is connected through an optical principle; the feed horn antenna is arranged at the focal point of the hyperboloid of the medium lens; the medium lens converges and collimates the spherical wave generated by the feed horn antenna to form a plane wave; the medium vortex lens transmits a stepped spiral structure to form a vortex electromagnetic wave; the vortex electromagnetic wave is designed according to a mode calculation formula of the vortex electromagnetic wave; theoretically, any required mode can be obtained; the vortex electromagnetic wave generated in this way has the characteristics of high power and is helpful to long-distance transmission in a wireless communication system. The high-gain medium vortex antenna has the advantages of high gain, high isolation and light weight.

Corrective meta surface lens is used to reduce the illumination and spill-over losses and improve the overall efficiency of a parabolic antenna when is horn-mounted, and / or top-mounted, and / or deposited directly on the frontal reflector surface of the parabolic antenna. For the horn-mounted model, a meta surface lens is placed in front of or in the aperture of the feed horn to reduce side lobe level, which results in lower parabolic antenna spill-over losses and overall efficiency improvement by more than 40% (1.5 dB). For the top-mounted model, the meta surface lens is mounted on top of (or above) the parabolic reflector, which results in reduction in illumination losses, and greater than 70% (2.5 dB) efficiency. The meta surface lens has a wideband response, is lightweight and has a lattice structure which makes it a great candidate for withstanding wind forces.

The invention discloses a broadband polarization insensitive 1-bit electrically-controlled programmable metasurface antenna, which comprises an electrically-controlled programmable metasurface and a feed horn, and is characterized in that the electrically-controlled programmable metasurface comprises M * N periodically arranged metasurface units, the unit comprises a first metal layer, a first high-frequency dielectric substrate, a second metal layer, a prepreg layer, a third metal layer, a second high-frequency dielectric substrate and a fourth metal layer which are sequentially and coaxially stacked from top to bottom. A metalized through hole is formed in the center of the metasurface unit; the metalized through hole vertically penetrates through each high-frequency dielectric substrate and the prepreg layer and is connected with all metal layers except the metal layer II; metalized blind holes are formed in the periphery of the metasurface unit, vertically penetrate through the first high-frequency dielectric substrate and are connected with the first metal layer and the second metal layer; four PIN diodes which are connected in parallel are arranged on the metal layer I; the metasurface antenna provided by the invention has the characteristics of wide frequency band, complete polarization compatibility, high polarization isolation and simple structure, and is suitable for satellite communication and 5 / 6G mobile communication.

The application discloses a kind of ultra-low profile high-gain circularly polarized folded transmission array antennas with low radar scattering cross section, including the chessboard type arrangement of PCM array, transmission array, reflecting array and feed horn;The chessboard type arrangement of PCM array is placed on transmission array, and the two are separated by air layer 1;The transmission array is placed on reflecting array, and the two are separated by air layer 2;The reflecting array center opens a rectangular hole, and the feed horn is placed in the rectangular hole and embedded.The folded transmission array antenna of the application has the wideband high-gain circularly polarized radiation performance, and the radar scattering cross section reduction of out-of-band double frequency.

The application discloses a hole bottom processing structure of a feed horn, and relates to the technical field of deep space exploration, weather measurement and satellite remote sensing.The hole bottom processing structure comprises a horn body and a ring-shaped assembly part, and a plurality of corrugated grooves with different diameters are formed in the horn body; a mounting block is arranged on one side of the horn body close to the hole bottom, a mounting cavity is formed in the mounting block, and one side of the mounting cavity is connected with the inside of the horn body. The ring-shaped assembly part is mounted in the mounting cavity, and the ring-shaped assembly part comprises first circular blocks and second circular blocks; five first circular blocks are arranged, the edges of adjacent first circular blocks are attached to each other, and the first circular blocks and the second circular blocks are fixed between the inside of the mounting cavity and the side wall of the mounting cavity through laser welding. The application avoids the problem that a tool cannot be deeply inserted into the hole bottom for processing due to the narrow hole in the horn by designing a split ring-shaped assembly part, and the effect of impedance mutation caused by uneven groove depth is eliminated by using a central hole with different diameters to form a continuous and uniform corrugated groove.

A microwave beam-forming antenna may include: a main reflector installed on one surface of an antenna body; an array feed horn installed on a center portion of the main reflector; a sub-reflector disposed to be spaced apart from the array feed horn on the main reflector; and a plurality of waveguide feeds respectively connected to a plurality of horn antennas arranged in the array feed horn.

The application discloses an optically transparent reflective array antenna and a preparation method thereof. The optically transparent reflective array antenna comprises, from top to bottom, a conductive unit array, a dielectric substrate and a conductive ground plate. The conductive unit array comprises a plurality of reflective array units. Each reflective array unit comprises three concentric circular metal thin wires, namely a first circle, a second circle and a third circle from outside to inside. The second circle and the third circle are connected by four center-symmetrical metal thin wires to form a circular ring structure. The length of the metal thin wire is fixed, and the radius of the first circle and the second circle is adjusted to realize the adjustment of the reflection phase. The finally assembled antenna array is excited by a feed horn to realize good performance of high gain, high efficiency and large bandwidth, while good visible light transparency is maintained. The technical problems of small phase shift range, large loss, narrow antenna operating bandwidth and low efficiency of the traditional optically transparent reflective array antenna unit are solved.

A system for counteracting antenna movement in a directional antenna, including a feed horn for providing an electromagnetic signal, a sub-reflector for controlling a direction of reflection of the electromagnetic signal provided by the feed horn, and a main reflector for reflecting the electromagnetic signal arriving from the sub-reflector and transmitting the electromagnetic signal reflected from the main reflector, wherein the sub-reflector includes a metasurface controllable to alter the direction of reflection of the electromagnetic signal by coordinated changes of phase over the sub-reflector surface. A sub-reflector for an antenna, the sub-reflector including a metasurface, wherein the metasurface is controllable to alter a direction of reflection of an electromagnetic signal by coordinated changes of phase over the sub-reflector surface. Related apparatus and methods are also described.

The invention discloses a monopulse feed source structure for a radar. The feed source structure comprises a monopulse horn, a coupler waveguide section and a comparator section from one end to the other end, the monopulse horn, the coupling waveguide section and the comparator section are all of a tailor-welded structure, every two adjacent sections are connected through a connecting flange plate, the flange plates are connected through pin positioning and screw connection, and a sealing rope is installed between the two flange plates. The production process of the parts is simple, so that the parts are easy to process and produce, and the processing precision of the feed source horn can be effectively ensured.