97results about How to "Good circular polarization performance" patented technology

The invention relates to an LTCC lamination double-fed circularly polarized micro-strip paster antenna, which belongs to the technical field of antennae and particularly relates to a micro-strip paster antenna with a low section. The antenna comprises two layers of radiation metal pasters, a grounding metal layer and a feed layer, wherein the four functional layers are spaced by three layers of medium LTCC ceramic dielectric substrates, and the feed layer consists of a Wilkins-layer power divider and a 90-degree phase shift micro-strip line. The geometric centers of the two layers of radiation metal pasters and the grounding metal layer are connected with each other by metal grounding pins, and the double-fed points with 90-degree phase difference on the feed layer are connected with the upper layer of radiation metal paster via metal feed pins. Two edges of each of the two layers of radiation metal pasters are respectively provided with two rectangular frequency modulation electrodes. The invention not only can better give consideration to the performance requirements of low section, broadband and circular polarization of the micro-strip antenna, but also can appropriately regulate the frequency band of the antenna conveniently.

The invention relates to an LTCC laminated coupling feed circularly polarized microstrip patch antenna, which belongs to the technical field of antennas. Including the feeding layer and the radiation layer dielectric substrate; the upper surface of the feeding layer dielectric substrate is a grounding metal layer with a "cross" shaped hollow area, and the lower surface has a feeding circuit and a shielding metal layer insulated from the feeding circuit; the feeding circuit Divide and phase-shift the incoming excitation signal into four branch excitation signals with equal amplitude and 90° phase difference, and couple to the radiation metal layer through the "cross" hollow area; the ground metal layer and the shielding metal layer pass through The evenly distributed metallized through holes are connected to each other; the radiation metal layer on the upper surface of the radiation layer dielectric substrate is a fractal pattern structure. The patches are formed iteratively in this way. The invention has the advantages of low profile, wide frequency band, circular polarization and miniaturization.

The invention relates to a dual-polarized oblique beam waveguide slot array antenna. The dual-polarized oblique beam waveguide slot array antenna comprises more than one unit array antenna; the unit array antenna is formed by a horizontally polarized linear array and a vertically polarized linear array; the horizontally polarized linear array and the vertically polarized linear array are arranged in a horizontal staggered mode; the horizontally polarized linear array is arranged on the upper layer; the vertically polarized linear array is arranged on the lower layer; a horizontally polarized single ridge waveguide is provided with a broadside V-shaped radiation slot; a vertically polarized single ridge waveguide is provided with a broadside U-shaped radiation slot; a feed portion is in a ridge waveguide form and accordingly the integral bandwidth of the antenna is effectively guaranteed, the antenna achieves beam inclination, meanwhile the matching bandwidth of the antenna and the radiation efficiency are guaranteed. The integral antenna can achieve a good circular polarization axial ratio characteristic and meanwhile achieve a 45-degree fixed beam inclination angle due to appropriate phase compensation of a feed network. Compared with the waveguide slot antenna at the same frequency band, the dual-polarized oblique beam waveguide slot array antenna is small in size, low in profile and effectively reduces costs due to a bolt fastening installation mode.

The invention discloses a double-frequency and double-polarization antenna capable of operating in a compass satellite navigation system and a mobile third-generation (3G) network and is implemented in a form of a laminated micro-strip circuit. The double-frequency and double-polarization antenna capable of operating in the compass satellite navigation system and the mobile 3G network comprises an upper-layer micro-strip antenna, a lower-layer micro-strip antenna and a metal floor layer, wherein the upper-layer micro-strip antenna has an upper-layer patch; the lower-layer micro-strip antenna has a lower-layer patch; the metal floor layer is arranged on a bottom layer; the upper-layer micro-strip antenna and the lower-layer micro-strip antenna share one metal floor layer; and the antenna is provided with six short-circuit metal columns which pass through the upper-layer micro-strip antenna and the lower-layer micro-strip antenna from the upper-layer patch and then are connected with the metal floor layer which is arranged on the bottom layer. The antenna adopts a feeding mode of dual-port coaxial feeding and has the advantages of simple and compact structure, miniaturization, convenience for processing and industrialized application, and the like.

The invention aims at overcoming the defects of an existing micro-strip patch antenna in the aspects of the high gain, the wide band and the circular polarization and providing a laminated circular polarization micro-strip patch antenna based on the LTCC technology. The antenna comprises an upper radiation metal patch antenna array layer, a lower radiation metal patch antenna array layer, an upper dielectric substrate layer, a lower dielectric substrate layer, a feed network, a grounding metal layer and a coaxial connector probe. The antenna is characterized in that the upper radiation metal patch antenna array layer and the lower radiation metal patch antenna array layer are the same in shape and size, each antenna array is composed of four small antenna arrays, each small antenna array is composed of four sub-arrays, each sub-array is composed of four radiation metal patches, each radiation metal patch is a square with a chamfer, and a set of opposite sides of each radiation metal patch are provided with rectangular gaps. The antenna can better meet the requirements for performance of the high gain, the wide band and the circular polarization of the micro-strip patch antenna, and the structure is simple.

The invention discloses a multi-mode satellite positioning navigation terminal antenna. The multi-mode satellite positioning navigation terminal antenna is characterized in that the antenna comprises a laminated microstrip patch antenna, a broadband orthogonal feed network and a connecting probe; the structure of the laminated microstrip patch antenna comprises a capacitor plate, an upper-layer patch, a lower-layer patch and ground from top to bottom; medium substrates are respectively arranged among the capacitor plate, the upper-layer patch, the lower-layer patch and the ground; simultaneously, air compensating layers are arranged among the medium substrate fixed with the capacitor plate, the medium substrate fixed with the upper-layer patch and the medium substrate fixed with the lower-layer patch; and the broadband orthogonal feed network consists of a Wilkinson power splitter and a 90-degree broadband phase shifter and is fixed on the medium substrate under the ground. The antenna has the characteristics of low cost, wide antenna beam, low elevation, high gain, and the like and is quite suitable for application to a high-precision satellite positioning navigation and time service system.

The invention discloses a liquid metal spiral antenna. The liquid metal spiral antenna is characterized by comprising a medium support body, a spiral radiation body, a feed matching body, a grounded panel and a radio frequency coaxial connector, wherein the medium support body is of a conical frustum structure arranged on the grounded panel, the feed matching body is attached to the lower portion of the outer wall of the medium support body, the radio frequency coaxial connector comprises an outer conductor and an inner conductor, the outer conductor and the inner conductor are arranged coaxially, the outer conductor is connected with the grounded panel, the inner conductor is connected with the feed matching body, the spiral radiation body comprises a lead-angle-variable spiral tube and liquid metal contained in the spiral tube, and the initial end of the spiral tube is attached to the feed matching body and wound spirally along the outer wall of the medium support body to form a cone. The spiral antenna is made reconfigurable, and the bandwidth of the liquid metal spiral antenna is larger than that of a solid metal antenna of the same structure and size.

The invention belongs to the technical field of antennas, provides an ultra-wideband low-profile circularly-polarized two-arm spiral antenna, and aims at solving the contradiction of consideration of ultra-wideband, low profile, circular polarization and high gain development of an existing spiral antenna. The spiral antenna comprises a back cavity, a radiator dielectric substrate, an antenna spiral arm, a balun and a coaxial joint, wherein a feeding port is formed in the center of the radiator dielectric substrate; the antenna spiral arm is located on the upper surface of the radiator dielectric substrate and is connected with the upper end of the balun through the feeding port; the balun is located in the back cavity; the lower end of the balun is connected with the coaxial joint; the back cavity comprises a cylinder and a slope; the cylinder is arranged at the center of the back cavity; the slope is connected with the cylinder; the cylinder and the slope jointly form a circular truncated cone; an annular groove and a window are formed in the cylinder; and the window is used for arranging the balun. By the spiral antenna provided by the invention, the performance requirements of the wide band, low profile, circular polarization and high gain of the spiral antenna are well considered; and meanwhile, the frequency band bandwidth of the antenna is greatly improved.

The invention provides a dual-band stacking medium loading spiral antenna, comprising two coaxial cylinder bodies with the upper part and the lower part stacked together; the sections of the bottom surface and the bottom part of the two cylinder bodies are provided with metal layers respectively, and the top ends thereof are respectively provided with four metal sheets with different lengths; one end of each metal sheet respectively extends radially from the center of the cylinder body to the circumference of the top surface and then to the metal layer axially in the spiral path from the surface of the metal sheet; the opposite surfaces of two adjacent metal sheets of the upper cylinder bodies are connected as two groups of antennas; the four metal sheets of the upper cylinder body and the lower cylinder body are respectively connected on the top end surface of the lower cylinder body; the dual-band stacking medium loading spiral antenna also comprises a cable which is embedded inside the through hole of the axle center and comprises an insulation body; the surface of the insulation body is covered by a conductive shield layer and the center thereof is provided with a feed-in needle; two ends of the feed-in needle extend out of the through hole; the top end of the conductive shield layer is connected with a group of the antennas of the upper cylinder body; the top end of the feed-in needle is connected with the other group of antennas of the upper cylinder body; the metal layers of the bottom surfaces of the upper cylinder body and the lower cylinder body respectively contact with the horizontal corresponding sections of the conductive shield layer. The antenna of the invention has small dimension and good performance.

A microstrip antenna using parasitical feed metal columns. The microstrip antenna includes four layers of dielectric plates, a radiating patch, metal floors, an SMP RF connector, a one-to-two power divider of a strip line form, a first feed metal column, a second feed metal column, a first parasitical feed metal column, and a second parasitical feed metal column. The antenna is additionally provided with the parasitical feed metal columns on the basis of a double-feed point circular polarization microstrip antenna, through electromagnetic coupling induction, the parasitical feed metal columns have electromagnetic field energy of a certain amplitude and phase, thereby changing surface current distribution of the microstrip antenna and electromagnetic field distribution between the microstrip antenna and the floors, so as to obtain a radiation pattern in rotational symmetry approximate to a ''four-feed point'' microstrip antenna, and at the same time, low elevation gain is improved, a feed network is simplified, feed loss is reduced, and the envelope size is diminished. The microstrip antenna using the parasitical feed metal columns in the invention is particularly suitable for occasions which have high requirements for miniaturization, rotational symmetry of a pattern and low elevation gain, and has popularization and application value.

The invention discloses a frequency / polarization / pattern-independent reconfigurable patch antenna by adopting a liquid crystal material to enhance polarization reconfigurable capability, which comprises a first dielectric plate, a second dielectric plate, an octagonal metal patch, an octagonal metal ring, diamond parasitic metal patches, a metal plate and a reconfigurable power division phase shifter with the liquid crystal material, wherein the second dielectric plate is located below the first dielectric plate, and the upper surface of the second dielectric plate coincides with the lower surface of the first dielectric plate; and the reconfigurable power division phase shifter with the liquid crystal material in the second dielectric plate is used for enhancing the polarization adjustment capability of the antenna under a different reconfigurable frequency. Independence and reconfigurability of the antenna frequency, the polarization and the pattern can be realized, the dielectric constant of the liquid crystal material is adjusted through controlling bias voltage, the polarization characteristics of the antenna under a different reconfigurable frequency can be adjusted, the circular polarization performance is improved, the polarization reconfigurable capability, of the antenna is further enhanced, and the antenna can be switched flexibly among different frequency bands, different polarization modes and different radiation points.

The invention discloses a high-performance multi-mode active satellite navigation antenna. The high-performance multi-mode active satellite navigation antenna comprises a surface-wave-restraining antenna, a dual-frequency-band orthogonal feed network, feed probes, short-circuit probes, a broadband low-noise amplifier and plastic screws, wherein the surface-wave-restraining antenna structurally comprises a capacitance board, a first dielectric substrate, a surface-wave-restraining patch, a second dielectric substrate and a base plate in sequence from top to bottom, a compensation air layer is arranged between the second dielectric substrate and the base plate, the surface-wave-restraining patch carries out coupling feed through the capacitance board, and is composed of a round patch and an annular patch, the broadband low-noise amplifier is arranged at below the dielectric substrates, an input port of the broadband low-noise amplifier is connected with an output port of the dual-frequency-band orthogonal feed network through a coaxial cable, and the surface-wave-restraining antenna and the dual-frequency-band orthogonal feed network are fixed through the plastic screws. The high-performance multi-mode active satellite navigation antenna has the advantages of being good in multi-path interference resistance capacity, high in gain, good in circular polarization performance and particularly applicable to a high-precision satellite positioning navigation and timing system.

The invention discloses a low-profile two-dimensional wide-angle scanning circular polarization phased-array antenna, and aims to provide an antenna structure which is easy to integrate and has good wide-angle scanning gain characteristics and circular polarization characteristics. According to the technical scheme, each 3D structure antenna unit forms an array unit of the two-dimensional wide-angle scanning circular polarization phased-array antenna through metal columns which are arranged between an annular radiator and a circular polarization patch slotting radiator in a circumferential circular array mode; each 3D structure antenna unit is fixed on the two-dimensional layer surface of the upper dielectric plate through a feed column fixedly connected to the lower surface of the circularly polarized slotted patch radiator; the feed column penetrates through the lower dielectric plate, the four 3D structure antenna units are connected with the annular radiator upwards and are connected with the feed base disc downwards, the four adjacent 3D structure antenna units form a 2*2 rectangular arrangement subarray in a touch type feed and 90-degree sequential rotation arrangement mode,and the four feed base discs are delayed by 90 degrees clockwise in sequence for feeding, so that the optimal right-handed circular polarization performance is obtained.

The invention relates to a satellite-borne K-band phased array antenna circularly-polarized waveguide radiation array, which can radiate microwave signals to the space, and can receive microwave signals from the space. The satellite-borne K-band phased array antenna circularly-polarized waveguide radiation array is composed of a plurality of antenna units, wherein each antenna unit comprises a matching diaphragm, an SMP coaxial feed socket, a square waveguide radiator, a waveguide-to-coaxial adapter, an SMP feed socket feed end, an impedance matching device and a circular polarizer, and adopts an integral design; and the matching diaphragms are adopted among the antenna units for deploying coupling characteristics among radiating units, so as to achieve more ideal standing wave performance and radiation characteristics. The satellite-borne K-band phased array antenna circularly-polarized waveguide radiation array is simple and reliable in structure, has the advantages of two-directional plus / minus 40-degree wide angle scanning, low sweep gain drop and excellent circular polarization characteristics, and satisfies the requirements for an phased-array antenna of satellite-borne intersatellite and satellite-to-ground communication. The antenna adopts an aluminum structure, and performances of the antenna are not affected by factors such as elemental oxygen corrosion and ultraviolet radiation of the on-orbit space environment.

The invention discloses a double-frequency dual-polarized antenna capable of working at a GPS (Global Position System) and TD-SCDMA (Time Division-Synchronization Code Division Multiple Access). The antenna comprises an upper layer micro-strip antenna, a lower-layer micro-strip antenna and a metal floor layer, wherein the upper layer micro-strip antenna is provided with an upper layer patch; the lower layer micro-strip antenna is provided with a lower layer patch; the metal floor layer is formed on a bottom layer; and the upper layer micro-strip antenna and the lower layer micro-strip antenna share one metal floor layer. The antenna is provided with two short-circuit metal posts which are connected with the metal floor layer on the bottom layer after being inserted into the upper layer micro-strip antenna and lower layer micro-strip antenna from the upper layer patch. In the invention, a laminated structure and a dual-port coaxial feeding mode are adopted for the antenna, so that the antenna has the advantages of simple and compact structure, small size, easiness for processing, and the like.

The invention belongs to the technical field of antennas, and discloses a ridge gap waveguide based circularly polarized antenna. The circularly polarized antenna is sequentially provided with a feed network layer and a radiation layer from bottom to top, and is characterized in that the feed network layer comprises a lower metal floor, periodically arranged metal pins, a power distribution metal ridge transmission structure and four through holes; the power distribution metal ridge transmission structure provides phase output with pairwise phase difference being 180 degrees according to the arrangement of four slot antennas; the slot radiation layer comprises an upper cover metal plate, four ring-shaped slots with braches and four through holes; and the four ring-shaped slotted slots with branches are distributed in a central symmetry manner, and the four slot antenna units radiate circularly polarized waves respectively and form a 2*2 circularly polarized antenna array. The impedance bandwidth of the antenna reaches up to 24.5%, the axis ratio bandwidth reaches up to 11.4%, and the gain in the frequency band can also meet requirements of practical applications. The ridge gap bandwidth based circularly polarized antenna stays at a high level in antennas of the same kind, and meets requirements of simple structure, small size and easy processing for antennas in practical applications.

The invention belongs to the technical field of antennas and provides an LTCC technology-based genome unit compact conformal array antenna. The invention mainly aims to solve the problem that the conventional circularly-polarized micro-strip patch array antennas fail to realize low profile, circular polarization, high gain and wide band at the same time. The antenna comprises a grounding metal layer, a lower layer dielectric substrate, a lower layer metal patch antenna, an upper dielectric substrate and an upper layer metal patch antenna, which are successively stacked from bottom to top; the lower layer metal patch antennal is formed from lower layer metal patch units in array arrangement; the upper layer metal patch antenna is formed from upper layer metal patch subarrays corresponding to the lower layer metal patch units; each upper layer metal patch subarray and the corresponding lower layer metal patch unit have coinciding centers and form a genome unit together. Under the limit of the same number of array numbers, the antenna is smaller in size, higher in gain, better in circular polarization performance and greater in frequency bandwidth, and is simple in structure and easy to process.

The invention belongs to the technical field of antennas, and particularly relates to a novel LTCC broadband circularly-polarized micro-strip patch array antenna which is used for overcoming the disadvantages of an existing circularly-polarized micro-strip patch array antenna in the aspect of giving consideration to low profile, circular polarization, high gain and broad band. The antenna comprises a grounding metal layer, a lower dielectric substrate, a lower metal patch antenna, an upper dielectric substrate and an upper metal patch antenna which are laminated in sequence from bottom to top, wherein the upper metal patch antenna is composed of a plurality of upper metal patch units in array arrangement; the lower metal patch antenna is composed of a plurality of lower metal patch units in array arrangement; the upper metal patch units and the lower metal patch units adopt chamfered square metal patches with the same dimensions, and rectangular grooves are formed in chamfers; rectangular gaps are formed in four sides of each upper metal patch unit; and rectangular gaps are also formed in other three sides, except the feed side, of each upper metal patch unit. The antenna is smaller in dimensions, higher in gain, better in circular polarization performance and wider in frequency bandwidth under the restriction of same array element number.

The invention relates to a small circularly-polarized antenna comprising a feeding plate and four radiation oscillators mounted on one side face of the feeding plate. The feeding plate is provided with a feeding network, and the feeding network has four output ends which are respectively connected with the four radiation oscillators and used for generating four equal-power signals, of which the phase difference is 90 degrees, and respectively outputting the four signals to the four radiation oscillators. The radiation oscillators are PIFA oscillators, and low-loss insulating medium or gas of which the dielectric constant is greater than 2 is filled between horizontal portions of the radiation oscillators and the surface of the feeding plate. According to the small circularly-polarized antenna provided by the embodiment of the invention, by filling high-dielectric-constant low-loss insulating medium between the PIFA radiation oscillators and the feeding plate, the size of the antenna is greatly reduced, circular polarization is realized, and meanwhile, the cost of production is lowered. Compared with the prior art, the small circularly-polarized antenna of the invention has the advantages of small size, low profile, good circular polarization performance, high gain and the like.

The invention discloses a novel RFID circularly polarized antenna, and belongs to the technical field of antennas. The antenna comprises a dielectric substrate, a metal ground plate, a square ring radiation patch and a Wilkinson power divider, wherein the metal ground plate is arranged on the lower surface of the substrate; and the square ring radiation patch is arranged on the upper surface of the substrate. The antenna disclosed by the invention is in a planar structure, and applicable to application in a plurality of environments; the radiation of the antenna is a bidirectional circularly-polarized radiation; and compared with a unidirectional radiation, the bidirectional circularly-polarized radiation has higher practicability on an RFID system and meets the requirements of the occasions, such as automatic fare collection systems for expressways and partial production lines, employing the RFID system.

The invention relates to a Ka frequency range miniaturization broadband multimode auto-tracking feed source network. Two polarization degenerate modes of TE21 mode transmitted by center circular waveguide are coupled to four rectangular waveguide by adopting a four-arm circular polarization TE21 coupler. Two four-way polarization degenerate modes of the TE21 mode is combined into two two-way polarization degenerate modes of the TE21 mode by two broadband magic Ts. A left-handed or right-handed circular polarization difference mode is output by a broadband 90-degree electrical bridge. The TE21 coupler center circular waveguide is capable of simultaneously transmitting a TE11 mode. Due to the fact that the TE21 coupler is connected with a broadband circular polarization machine, and two polarization modes of a signal are respectively output from two ports of the broadband circular polarization machine, the Ka frequency range miniaturization broadband multimode auto-tracking feed source network is capable of simultaneously receiving a signal of double-circular polarization and a difference signal, and thereby the auto-tracking function is realized. The Ka frequency range miniaturization broadband multimode auto-tracking feed source network has the advantages of not only simplifying composition of the feed source network, reducing the volume and the weight of the whole device, but also reducing network construction, saving feed source cost and broadening working band of the feed source network.

The invention discloses a broadband circular polarizer. The broadband circular polarizer comprises a plurality of substrate layers, and a plurality of artificial microstructures periodically arranged between adjacent substrate layers to form a plurality of artificial microstructure layers, wherein the artificial microstructure is a rectangular metal sheet; the single artificial microstructure layer is identical in topological structure and size of the artificial microstructure; the size of the rectangular metal sheet of different artificial microstructure layers increases gradually to a maximum value and then decreases gradually. The broadband circular polarizer provided by the invention is designed based on the metamaterial principle, is simple in structure and can realize good circular polarization effect in 30 to 40GHz. In addition, the broadband circular polarizer can meet the requirement for impedance matching of electromagnetic wave propagation by gradually increasing and then gradually decreasing the size of the artificial microstructures along the electromagnetic wave propagation direction, thereby reducing the electromagnetic wave reflection and improving the gain.

The invention discloses a magnetic coupling feeding based circularly polarized antenna. The circularly polarized antenna comprises an antenna shell, a feeding part and a polarized metal sheet, wherein the feeding part is arranged at the feeding end of the antenna shell; the polarized metal sheet is arranged at the radiating end of the antenna shell; a rectangular waveguide cavity and a circular waveguide cavity are formed in the radiating end of the antenna shell; the polarized metal sheet is arranged on the axial line of the circular waveguide cavity; a signal fed by a signal feeding probe of the feeding part is transmitted to the rectangular waveguide cavity through a magnetic coupling curved needle for converting a TEM mode into a TE10 mode of the rectangular waveguide; then the signal passes through the circular waveguide cavity for converting the TE10 mode into a TE11 mode; and finally, the TE11 mode is subjected to polarization adjustment by the polarized metal sheet to radiate circularly polarized electromagnetic wave. Therefore, the feeding point can be set on the geometric axial line of the antenna; and meanwhile, the antenna has a relatively small size and relatively high circularly polarized performance.

The invention belongs to the field of satellite mobile communication, and particularly provides a low-profile circularly polarized microstrip antenna for satellite communication, which is used for overcoming the problems of narrow beam width, higher profile, narrower working bandwidth, larger transverse size and the like of the existing satellite communication antenna. According to the invention,the microstrip four-element array design that the microstrip four-element arrays are arranged around the center of the upper dielectric substrate at equal intervals in sequence is adopted, so the antenna has good circular polarization performance; meanwhile, by adjusting the distance between the array elements, the current distribution of the diagonal array elements can be controlled, so the antenna realizes wide-beam radiation; moreover, an air layer is introduced between the radiator and the metal reflecting layer, and the bandwidth of the antenna can be broadened by adjusting the thicknessof the air layer. Most importantly, compared with an antenna with the same performance, the antenna has an extremely low profile, 0.068lambda0 can be achieved, and the antenna is more suitable for high-speed moving aerial or ground carriers with large wind resistance in satellite communication.

The invention discloses a wide wave beam circular polarization micro-strip antenna, and belongs to the field of micro-strip antennas. The wide wave beam circular polarization micro-strip antenna comprises a micro-strip antenna body and an insulation drum (2). The wall of the insulation drum (2) is solid, and the micro-strip antenna body is arranged at the bottom of the insulation drum (2). The center of the insulation drum (2) and the center of the micro-strip antenna body are located on the same vertical line. The wide wave beam circular polarization micro-strip antenna has the advantages of being wide in wave beam, good in circular polarization performance, symmetric in directional diagram, simple in structure, easy to process, and suitable for being applied to the fields of satellite navigation and communication.

The invention discloses a planar microstrip patch antenna with broadband end-fire circular polarization characteristics. The antenna comprises a single-layer dielectric substrate, an upper metal patchand a lower metal patch, wherein the single-layer dielectric substrate comprises a bent metal wall, a coaxial feed probe and a loading metal probe which are arranged sequentially; the coaxial feed probe is used to feed the energy of the antenna; the bent metal wall is used as a reflection cavity; the loading metal probe is used for adjusting the impedance matching performance of the antenna; theupper metal patch and the lower metal patch sequentially comprise rectangular patches, arc-shaped gradient slot apertures, feed strips and fan-shaped dipole patches from one side to the other side; the arc-shaped gradient slot aperture is used for exciting a vertical polarization component; the feed strip is used for transferring the energy to the fan-shaped dipole patch; and a horizontal polarization component is excited by the fan-shaped dipole patch. The broadband circular polarization radiation function of the planar microstrip patch antenna is realized, and the planar microstrip patch antenna has the advantages of simple structure and wide common bandwidth of impedance and axial ratio.

The invention provides an X-band circularly polarized array antenna, which comprises a dielectric substrate, a plurality of radiation unit patches, a feed network, impedance converters, a metal groundplate and an input connector, wherein the plurality of radiation unit patches are arranged at the front of the dielectric substrate, the impedance converters connect the radiation unit patches and the feed network, the metal ground plate and the input connector are arranged at the back of the dielectric substrate, and the input connector is connected with a feed point of the feed network throughthe metal ground plate and the dielectric substrate; and the radiation unit patches are of a corner feeding mode, and the radiation unit patches are arranged at two sides of the feed network in a staggered mode. According to the invention, The X-band circularly polarized array antenna feeds the radiation unit patches in a corner feeding mode, so that the circular polarization performance can be better met compared with a linearly polarized array, and thus the anti-interference ability is high. In addition, the radiation unit patches are arranged at two sides of the feed network in a staggeredmode, so that the size in the transverse direction is small compared with a linear array antenna. Furthermore, the invention further provides ship radar containing the antenna, which has the effects mentioned above.

An RFID circularly polarized air microstrip antenna provided by the invention is characterized in that a lower-layer metal radiation patch is arranged above a metal grounding plate, and an upper-layermetal radiation patch is arranged above the lower-layer metal radiation patch; a metal pillar is fixedly installed in the center of the metal grounding plate, and the upper metal radiation patch andthe lower metal radiation patch are fixedly installed on the metal pillar through the installation holes respectively; a feed network is L-shaped and is connected with the lower radiation patch, a metal tuning sheet is arranged between the feed network and the metal grounding plate, a metal screw is arranged between the metal tuning sheet and the feed network, and a feed probe is welded at the bottom of the metal tuning sheet. The antenna has the advantages of being small in size, low in profile, large in gain, wider in 3dB axial ratio and impedance bandwidth and the like, the impedance bandwidth of the antenna can be increased, the standing-wave ratio of the antenna can be reduced, the axial ratio of the antenna can be effectively reduced, and the ideal axial ratio bandwidth can be obtained.

The invention discloses an array antenna and a method for improving the circular polarization performance thereof, the array antenna comprises a first unit, a second unit, a third unit and a fourth unit distributed in a rectangular array, wherein the first unit, the second unit, The third unit and the fourth unit have the same structure, and the first unit, the second unit, the third unit and thefourth unit are provided with feeding striplines, wherein the second unit is deflected by 90 degrees with respect to the first unit, the third unit is deflected by 180 degrees with respect to the first unit, and the fourth unit is deflected by 270 degrees with respect to the first unit. By changing the structure of the array antenna unit and then rotating the antenna element regularly, the instantaneous components of the instantaneous electric field vector of the array antenna element on the x-axis and y-axis in the two-dimensional coordinate system are nearly equal, so that the circularly polarized trajectory of the array antenna electromagnetic wave is nearly circular, and the circularly polarized performance of the array antenna is further improved.