189 results about "Impedance bandwidth" patented technology

The invention provides a wide-angle scanning dual-circularly-polarized phased-array antenna unit, which belongs to the field of dual-circularly-polarized antennas and comprises a first dielectric layer, a second dielectric layer and a third dielectric layer which are sequentially stacked, the antenna radiator is arranged on the side, away from the second dielectric layer, of the first dielectric layer, the antenna radiator comprises four radiation patches, each radiation patch comprises a metal patch and a loading branch knot, and each metal patch is provided with a slotted structure; the first metal ground layer is clamped between the first dielectric layer and the second dielectric layer, and a cross coupling gap and a first coupling gap and a second coupling gap which are perpendicular to each other are formed in the first metal ground layer; the U-shaped feeder line is clamped between the second dielectric layer and the third dielectric layer, and two ends of the U-shaped feeder line are respectively connected with a coaxial feed column penetrating through the third dielectric layer; the second metal ground layer is arranged on the side, away from the second dielectric layer, of the third dielectric layer; an array is also provided; the problem that a traditional circularly polarized antenna is narrow in impedance bandwidth and limited in polarization is solved.

The invention relates to a circularly polarized quasi-absorption filtering phased-array antenna. A unit of the antenna comprises a multi-layer dielectric substrate, a semi-cured layer, a metal floor, a stacked patch and an orthogonal H-shaped gap, the first dielectric substrate is provided with a parasitic square loop, the second dielectric substrate is provided with a cross-shaped strip, and radiation zero points are introduced to the upper and lower edges of a passband respectively; the 3dB orthogonal directional coupler and the L-shaped feeder form a feed network, circularly polarized radiation is realized through slot coupling, and an isolation port of the 3dB orthogonal directional coupler is connected with a 50-ohm resistor, so that the energy of a lower stop band is absorbed, the energy of an upper stop band is reflected, and a quasi-absorption filtering characteristic is presented; the antenna is compact in structure and easy to process, has wide axial ratio bandwidth and good filtering performance, and when array scanning is 0-45 degrees, the overlapping impedance bandwidth is 12%, the axial ratio bandwidth is 15.8%, and the maximum scanning loss is 2.3 dB; the antenna is compact in structure and easy to process, has wide axial ratio bandwidth and good quasi-absorption filtering performance, and has huge potential in millimeter wave satellite communication application.

The invention discloses a Ka-band four-tilt-beam magnetoelectric dipole antenna, and belongs to the technical field of millimeter wave radio frequency front-end devices. Based on a magnetoelectric dipole composite radiation structure, four centrosymmetric radiation units are integrated on a low-loss substrate. The antenna comprises a probe patch of a coaxial gamma-shaped feed probe, a radiation patch, a parasitic patch, an upper dielectric substrate, a lower dielectric substrate, a middle curing layer, a shorter metal through hole of the coaxial gamma-shaped feed probe, a longer metal through hole of the coaxial gamma-shaped feed probe, a metal through hole c of the radiation patch, a metal through hole d of the parasitic patch and a metal ground backboard, a probe patch, a radiation patch and a parasitic patch of the coaxial gamma-shaped feed probe are located on the upper surface of the upper-layer dielectric substrate, and a metal ground backboard is located on the lower surface of the lower-layer dielectric substrate; the antenna has ultra-wide impedance bandwidth, has the characteristics of low cost, miniaturization, low cross polarization and back lobe suppression, and is superior to a traditional inclined beam antenna and an antenna array scheme.

Provided in the present disclosure are a patch antenna, an antenna array and a communication device. The patch antenna comprises: a feed circuit, a slotted ground plane, and a first patch layer, a second patch layer and a third patch layer, which are sequentially stacked in the direction of the slotted ground plane facing away from the feed circuit and are spaced apart from each other, wherein the feed circuit comprises two feed ports and an open-loop annular feed portion connecting the two feed ports; the slotted ground plane is located on one side of the feed circuit; the slotted ground plane is provided with a plurality of slots; the slotted ground plane is spaced apart from the feed circuit; the orthographic projections of the slots on the feed circuit at least partially overlap the open-loop annular feed portion; and the first patch layer comprises a first patch, the second patch layer comprises a second patch, and the third patch layer comprises a first annular patch. The simplification of the structure of a polarization switchable antenna, the reduction of the return loss and the increase of the signal gain and impedance bandwidth are facilitated.

The invention discloses a low-profile and high-integration broadband dual-circularly-polarized transceiving common-aperture phased-array antenna, which adopts a multi-layer PCB (Printed Circuit Board) laminated structure, comprises a radiation patch layer, a quasi-rectangular patch layer, a metal reflection ground layer and a feed layer from top to bottom, and is combined with a metalized blind hole and a buried hole to form a complete coupling path. A U-shaped groove, a U-shaped metal strip and a C-shaped groove are integrated on a metal reflection ground, and a staggered groove is loaded on a quasi-rectangular patch, so that a K / Ka dual-band separated dual-coupled feed structure is realized, and dual circularly polarized radiation is obtained under the same aperture. The antenna is further provided with outer ring and inner ring plated-through hole arrays, the outer ring plated-through hole arrays are used for constructing an isolation area to improve the isolation degree between wavebands, and the inner ring plated-through hole arrays introduce a horizontal electric field component to improve the circular polarization purity and expand the axial ratio bandwidth. Wide impedance bandwidth and wide axial ratio bandwidth are realized in the K wave band and the Ka wave band, the isolation degree is high, the profile is low, the structure is compact, and the broadband phased array antenna is suitable for broadband phased array systems such as satellite communication terminals and mobile platforms.

The present application provides an antenna system and an electronic device. The antenna system includes a first antenna and a metal part. The metal part surrounds the first antenna, and a dielectric is filled between the metal part and the first antenna. The distance between the center line of the metal part and the first antenna is r, where 0.2×n×λ1 < r < 0.8×n×λ1, λ1 is the wavelength of electromagnetic waves propagating in the dielectric, n is a natural number, and 1 ≤ n ≤ 5. The height of the metal part is h, where 0.25λ2 < h < λ2, λ2 is the wavelength of electromagnetic waves propagating in the metal part. By making the distance between the center line of the metal part and the first antenna satisfy the above distance relationship and the height of the metal part satisfy the above height range, the first antenna can self-excite the first resonance mode, and the first antenna can also excite the second resonance mode on the metal part. The metal part does not block the electromagnetic waves radiated by the first antenna, and can also excite new resonance modes on the metal part, thereby significantly broadening both the impedance bandwidth and the efficiency bandwidth.

The invention discloses a broadband dual-circularly-polarized low-cost phased-array antenna array element, which comprises an antenna radiation structure and a slot feed structure which are arranged independently from each other, and is characterized in that the antenna radiation structure comprises a parasitic radiation layer, a first dielectric substrate, an excitation radiation layer and a second dielectric substrate which are arranged in a laminated manner; the slot feed structure comprises a slot layer, a third dielectric substrate, a strip-shaped transmission line and a fourth dielectric substrate; the antenna layer structure and the slot feed structure realize electromagnetic coupling transmission through the slot layer; a hollow symmetrical structure is arranged in the middle of the first dielectric substrate, and the hollow part is used as an air medium to reduce dielectric loss; the gap layer is provided with a multidirectional coupling gap structure; the strip-shaped transmission line is provided with at least two feed ports, and dual circularly polarized radiation is formed in the antenna layer structure through excitation of different feed ports. The antenna radiation layer has no metal through hole or blind hole, can be processed in a layered manner, has the advantages of low processing cost and high yield, and ensures impedance bandwidth while realizing dual circular polarization.

The invention discloses a high-speed peripheral component interconnection bandwidth allocation system, method and device, a medium and a product, and relates to the technical field of computers. The system comprises an adapter card, an impedance circuit and a basic input and output system. The impedance circuit is integrated on the adapter card, when adapter cards of different specifications are inserted, output of different impedance signals can be achieved through the state change of the impedance circuit on the adapter card, and in the power-on self-test stage, the impedance signal output can be achieved. And the basic input and output system determines the bandwidth of each high-speed peripheral component interconnection channel according to the impedance value and a preset impedance bandwidth mapping table. Therefore, when the adapter card is replaced, operations such as circuit redesign and impedance matching element adjustment do not need to be carried out on the mainboard, and the universality of high-speed peripheral component interconnection bandwidth allocation is improved. Besides, the basic input and output system automatically obtains the impedance value and determines the bandwidth through the power-on self-test stage, firmware configuration parameters do not need to be modified manually, and the flexibility of server hardware configuration is enhanced.

The invention relates to a low-profile dual-polarization metasurface filtering antenna applied to Sub-6GHz, which comprises a first dielectric substrate, a metasurface is printed on the upper surface of the first dielectric substrate, a second dielectric substrate is downwards arranged on the upper surface of the first dielectric substrate, a metal floor is clamped between the first dielectric substrate and the second dielectric substrate, a first metalized through hole and a second metalized through hole are formed in the second dielectric substrate, and the first metalized through hole is communicated with the second metalized through hole. A first microstrip feeder line and a second microstrip feeder line are printed on the lower surface of the second dielectric substrate, and the first microstrip feeder line and the second microstrip feeder line intersect vertically. According to the invention, the metasurface structure is introduced, and by means of the metasurface structure, the antenna obtains a relatively wide impedance bandwidth 21.61% and a relatively high gain; under the condition that an extra filter circuit is not introduced, the low-frequency radiation zero point is introduced only by adding the n-shaped branch knot, and the radiation zero point frequency and out-of-band rejection can be adjusted by adjusting related parameters; according to the invention, while high isolation is realized, the cross polarization discrimination rate also exceeds 30dB; the antenna is simple in overall structure, low in manufacturing cost and easy to integrate.

The invention discloses a dual circularly polarized phased-array antenna based on triangular grid arrangement. A phased-array antenna module sub-array is formed by triangular grid arrangement of phased-array antenna units; the radiation unit adopts a cross oscillator with a gradual change structure, the impedance matching is improved, and a feed network of a three-branch linear bridge is matched, so that the impedance bandwidth of the antenna is improved, and the requirements of more communication frequency bands are met; the orthohexagonal antenna unit appearance and the metal partition wall are adopted, so that mutual coupling between the antenna units is reduced, and the isolation degree between the antenna units and the overall performance are improved; triangular grid arrangement is adopted, and the problems that the scanning range of a traditional rectangular array is limited, and grating lobes are prone to occurring during large-angle scanning are solved; the device has higher polarization purity and lower cross polarization level, supports quick splicing of N * N subarrays, and has the advantages of simple structure, low cost and easiness in processing.

The invention relates to a planar end-fire dual-frequency circularly polarized antenna with a small frequency ratio, which comprises a first magnetic dipole unit used for providing a vertical polarization component, and the first magnetic dipole unit comprises a medium, a first patch assembly, a first short circuit assembly and a feed end, the first patch assembly and the first short circuit assembly form a first cavity; the feed end is arranged on the first patch assembly; the second electric dipole unit comprises a first folding structure and a second folding structure, the second folding structure is a reverse folding structure of the first folding structure, and the second folding structure and the first folding structure form a complementary structure at the tail end. According to the invention, the structure is simple, the requirements of circular polarization phases of two frequency bands can be met at the same time, and the design complexity and the processing and manufacturing cost are greatly reduced; the complementary structure of the folded electric dipole tail end structure and the reverse extension branch knot can realize a small frequency ratio of about 1.3, and has the advantages of high gain and wide impedance bandwidth at high frequency.

The invention discloses a broadband wide-beam millimeter wave magnetoelectric dipole antenna, and belongs to the technical field of radio frequency front-end devices. The antenna mainly structurally comprises an upper-layer dielectric plate, a middle-layer dielectric plate, a lower-layer dielectric plate, a metal radiation through hole, a metal radiation patch, a parasitic unit through hole, a parasitic unit patch, a left feed through hole, a right feed through hole, a metal feed patch, a coaxial line and a metal ground. Wide impedance bandwidth in the range of 18.2-40.3 GHz is realized when the antenna works in a millimeter wave frequency band, the relative bandwidth exceeds 75%, and the antenna has wide beam width performance; the structure is simple and manufacturing is convenient.

The present invention discloses a broadband dual-polarized slot hollow waveguide antenna, which includes a radiation slot layer, an H-polarization full-common-feed feeding network, an orthogonal mode separation layer, and a V-polarization full-common-feed feeding network stacked from top to bottom. The V-polarization full-common-feed feeding network adopts a bottom-feed feeding method to excite the radiation slot layer to generate vertically polarized waves. The H-polarization full-common-feed feeding network adopts a side-feed feeding method to cause the radiation slot layer to generate horizontally polarized waves. The orthogonal mode separation layer is designed based on a double-ridge rectangular waveguide cavity. The radiation slot layer is used to generate vertically polarized waves under the excitation of the V-polarization full-common-feed feeding network and horizontally polarized waves under the excitation of the H-polarization full-common-feed feeding network, and synthesize the vertically polarized waves and the horizontally polarized waves into cross-polarized waves and radiate them into free space. The advantages are that while having a relatively wide impedance bandwidth, the grating lobe level will not deteriorate significantly, and it has a high antenna efficiency and a high cross-polarization (XPD).

The invention discloses a dual-port coaxial feed circular polarization magnetoelectric dipole antenna, and belongs to the technical field of millimeter wave satellite communication antennas. The antenna comprises a first metal patch layer, a dielectric substrate a, a second metal patch layer, a dielectric substrate b and a metal ground which are sequentially stacked from top to bottom, the second metal patch layer comprises four radiation patches which are arranged in a rectangular array, and each radiation patch is composed of a square patch and a circular ring patch at an inner corner; a metal through hole is formed in the dielectric substrate and is connected with the radiation patch and the metal ground, so that a magnetoelectric dipole radiation path is formed; the first metal patch layer is provided with a probe patch a, the center of the second metal patch layer is provided with a probe patch b, and the probe patch a and the probe patch b form two space orthogonal inverted L-shaped feed probes through a short column and a long column respectively; and the inner conductors of the two feed ports are respectively connected with the long columns of the two probes. The antenna has the advantages of wide impedance bandwidth, wide beam coverage, low profile and easy integration, and is suitable for a low-orbit satellite communication terminal.

The invention discloses a low-profile broadband circularly polarized antenna for an ultra-wideband positioning system. The low-profile broadband circularly polarized antenna comprises a first dielectric substrate, a grounding plate and a second dielectric substrate, the first dielectric substrate, the grounding plate and the second dielectric substrate are sequentially attached from top to bottom; a plurality of circular metal patches are arranged on the upper surface of the first dielectric substrate to form a metasurface structure; a Z-shaped gap is etched in the grounding plate; the lower surface of the second dielectric substrate is provided with a microstrip feed structure, and the microstrip feed structure comprises a microstrip line, a feed branch with a gradual change structure, and an SMA connector. One end of the microstrip line is connected with the feed branch with the gradual change structure, and the other end is connected with the SMA connector. The circular metal patch is adopted to form the metasurface structure, the rectangular gaps of different sizes are etched in the center of the circular metal patch, the feed branch knot with the gradual change structure is coupled with the Z-shaped gap to excite the metasurface structure to generate circular polarization radiation, and large circular polarization bandwidth and impedance bandwidth are achieved.

The present invention provides a novel squiggly shaped taper for achieving an impedance matching for the larger bandwidth frequency ranging from 3 GHz to 20 GHz. The said squiggly shaped taper has size of 30×35 mm2 and comprises a circular metallic patch 102 with dielectric substrate 101 and Perfect Electrical Conductor 103 placed on one side and other side remains blank as a single sided PCB. all patch, ground, and tapered feed are comprised of 0.035 mm PEC, and the tapered feed comprises two feed widths inner feed P1 and another feed as P2 and the value of other feed varies with the value of S-parameter. The feed provides zig zag arrangement structure 105 where simultaneous increase and decrease of feed is achieved; the said dielectric substrate 101 is comprising of a FR 4 material exhibiting a dielectric constant of 4.4, thickness of 0.16 mm and loss tangent of 0.0024; further the said antenna provides an impedance bandwidth of 144% from 3.3 GHz to 20.3 GHz and a gain of 5.167 dBi at 14.9 GHz frequency and covers whole Ultra-wide band.

A dual-resonant antenna device is provided, exhibiting improved impedance bandwidth, cross-polarization, and isolation, and is less susceptible to spurious surface wave excitation. More specifically, at least one antenna element and a resonant structure are provided on a non-conductive substrate, such that at least one continuous conductive sidewall of the resonant structure surrounds the one or more antenna elements, forming a resonant cavity filled with a dielectric material covering the one or more antenna elements. Each antenna element is used to excite a TM mode, while the dielectric material and size of the resonant cavity are selected such that the resonant structure is used to excite a TE mode. In a preferred embodiment, the TM mode is a TM 01 mode, and the TE mode is a TE 111 mode.

The present invention belongs to the field of radar antenna technology, specifically an ultra-low sidelobe, high-gain metal waveguide slot antenna with a surface modulation structure. The antenna of the present invention consists of a radiating waveguide with a slot on a wide side, plate reflectors installed on both sides of the radiating waveguide at a certain angle, and a feeding waveguide tightly attached to the bottom of the radiating waveguide; wherein, a row of metal cylinders are respectively provided on the upper surface of the radiating waveguide and on both sides of the middle radiating slot, and the metal cylinders are fixed to the PMI foam strips on the narrow side of the waveguide; the arrangement of the reflectors and metal cylinders can be used to correct the E-plane radiation pattern of the metal waveguide antenna, thereby increasing the gain while minimizing the sidelobes. The array impedance bandwidth can reach 2%, the E-plane sidelobes are almost ‑22 dB, and the H-plane sidelobes are almost ‑30 dB. The arrangement is relatively compact and the reliability is extremely high.

The present invention discloses a microstrip line tuning circuit. The tuning circuit is composed of a single-layer PCB circuit board, and the single-layer PCB circuit board consists of three parts: a front copper-clad microstrip line, a dielectric board, and a back copper-clad ground plane. The front copper-clad microstrip line includes: an input pad, an output pad, an input impedance transformation section, an output impedance transformation section, and a resonator composed of a plurality of parallel open stubs. The above resonator eliminates the impedance discontinuity phenomenon caused by electromagnetic mode conversion near the corresponding frequency point of the ultra-wideband radiation unit through "anti-resonance", so as to achieve the purpose of expanding the impedance bandwidth. Considering that the most widely used base station antenna radiation units currently basically operate below the third-order mode, the above microstrip line tuning circuit is optimized to a suitable resonance frequency, and theoretically adapts to almost all radiation units, significantly improving the impedance bandwidth. The present invention also provides a base station antenna.

The utility model discloses a dual-output high-precision vehicle-mounted GNSS (Global Navigation Satellite System) antenna, and relates to the technical field of positioning antennas. The receiving unit comprises a first microstrip patch, a second microstrip patch, an L1 antenna feed network, an L2 antenna feed network, an L1 prefilter, an L2 prefilter, an L1 pre-amplifier, an L2 pre-amplifier, an L1 filter, an L2 filter, a pilot frequency combiner circuit, a final amplifier, a splitter, a power switching circuit, a first switch, a second switch, a first connector and a second connector. The first microstrip patch is arranged above the second microstrip patch, and the L1 antenna feed network and the L2 antenna feed network are connected to the second microstrip patch. The device can realize miniaturization, expand the impedance bandwidth of the antenna, realize the reception of multi-constellation satellites and low-elevation satellites of the antenna, and meet the requirements of a high-precision inertial navigation module on the antenna.

This invention relates to a broadband high-gain radar antenna based on a metasurface and its applications, belonging to the field of antenna design. From top to bottom, it consists of a metasurface layer (Rogers RO3003C substrate + periodic ideal electrical conductor rectangular elements), an air cavity, a radiating layer (ideal electrical conductor patch with rectangular slots), a ground plane with rectangular slots, and a feed layer (microstrip line), operating near 12.4 GHz. The metasurface elements are optimized through characteristic mode analysis, the air cavity improves impedance matching, and the microstrip line is fed through the rectangular slots of the ground plane and the slots of the radiating layer. CST simulations show that the antenna has an impedance bandwidth of 1800 MHz in the 11.6–13.4 GHz range, a peak gain of 8.37 dBi, and a radiation efficiency of nearly 100%, making it suitable for millimeter-wave radar and providing new ideas for its miniaturization and high performance.

The invention provides an antenna unit and an antenna array, belongs to the technical field of antennas, and aims to broaden the impedance bandwidth and the axial ratio bandwidth of the antenna unit, the antenna unit comprises: a feed structure comprising a metal element for feeding; the radiation structure is coupled with the feed structure and comprises a radiation patch, and the radiation patch comprises a target point; wherein the radiation patch comprises at least one circle of slit pattern surrounding the target point, the slit pattern comprises a plurality of slits, and the plurality of slits are arranged at intervals along the perimeter direction of the radiation patch; wherein in the normal direction of the radiation patch, the distance between the metal element and the radiation patch is larger than 0 mm and smaller than or equal to 0.01 mm.

The application discloses a kind of millimeter wave broadband filtering antennas with wide-angle beam scanning function and array, from top to bottom include broadband radiator, metal ground layer and microstrip line feed layer in sequence, the broadband radiator includes first rectangular patch, second rectangular patch and driving patch;By controlling the size of first metal patch, second metal patch and driving patch, the resonant frequency of broadband radiator is regulated;By adjusting the distance between first rectangular patch, second rectangular patch and driving patch, and the spacing of adjacent first metal patch and adjacent second metal patch, the coupling amount of broadband radiator is regulated, and the bandwidth of broadband radiator is further regulated.The application has simple and compact structure, wide impedance bandwidth, and can cover four millimeter wave frequency bands.

This application discloses a wide-beam cavity antenna element and its phased array antenna. The cavity antenna element includes a first radiating patch, a first dielectric layer, a second radiating patch, an adhesive layer, a second dielectric layer, and a metal ground layer arranged sequentially. The first radiating patch has a first chamfer on each diagonal and a first U-shaped slot in its center. The second radiating patch has a second chamfer on each diagonal and a second U-shaped slot in its center. This application adopts a dual-radiating patch structure, with the first and second radiating patches located in different dielectric layers, effectively expanding the antenna bandwidth and improving radiation efficiency. The double-layer square microstrip patch design is compact and facilitates miniaturization and integration. The first radiating patch incorporates the first chamfer and the first U-shaped slot, while the second radiating patch incorporates the second chamfer and the second U-shaped slot, increasing the current path and transforming the original single resonant point into three resonant points within the frequency band, significantly widening the antenna's impedance bandwidth.

The application discloses a circularly polarized logarithmic-periodic antenna based on rotation of radiating oscillators, and belongs to the technical field of antenna engineering, and aims at solving the problem of how to design a circularly polarized logarithmic-periodic antenna with wide bandwidth, low profile and simple structure. The application forms corresponding circularly polarized characteristics by rotating a plurality of groups of radiating oscillators by a certain angle with parallel assembly lines as the shaft. The antenna only has a plurality of radiating oscillators which change according to the logarithmic-periodic antenna rule, and does not have a main oscillator and a sub-oscillator, so that the structure is simpler and easier to realize. Meanwhile, the circularly polarized effect is formed by rotating the radiating oscillators to a certain phase and the phase difference between the electromagnetic waves of each oscillator and the zero point of the antenna, so that the logarithmic-periodic antenna can obtain good impedance bandwidth and 3dB axial ratio bandwidth in the working frequency band.

The application discloses a kind of super surface circularly polarized antennas, belong to wireless communication technical field, including: super surface, super surface includes a plurality of first super surface units and a plurality of second super surface units arranged in array, first super surface unit is located in the periphery of second super surface unit, and second super surface unit is the symmetrical structure formed by cutting first super surface unit;Dielectric substrate, dielectric substrate includes upper layer dielectric substrate and lower layer dielectric substrate;Driving patch, driving patch is located between upper layer dielectric substrate and lower layer dielectric substrate;Metal floor, metal bottom plate is arranged on the lower surface of lower layer dielectric substrate;Microstrip feed structure, through coupling gap and driving patch non-contact coupling;By unit array optimization, phase difference is generated in orthogonal radiation mode, and circularly polarized radiation is realized.50 ohm microstrip line feeding is used, and non-contact coupling excitation is realized by coupling gap and driving patch;Synergistic design realizes 31.5% impedance bandwidth, 20.4% axial ratio bandwidth, and full coverage WBAN5.15-5.825GHz frequency band.

Wideband antenna elements exhibit strong coupling when formed into an array, which normally degrades the impedance bandwidth, radiation pattern, and efficiency of the feed antennas. Various methods are provided herein to mitigate or reduce this coupling. For example, designing an array such that not all antennas support the lower frequency operation mitigates coupling at low frequencies where coupling is most significant. Alternatively, embedding the feeds into a high-refractive-index medium increases the electrical distance between feeds while the physical separation is kept constant.

The application discloses a P-waveband broadband characteristic planar dipole antenna and belongs to the technical field of decimeter wave radio frequency front-end devices. A pair of printed planar dipoles composed of a half-elliptical part and a rectangular part and respectively located on the upper and lower surfaces of a dielectric substrate form the main radiation structure of the antenna. A metal base is composed of a metal side wall and a metal ground back plate, the metal side wall plays a role of supporting the dielectric substrate and also plays a role of a parasitic element, the current of the dipole is coupled to the parasitic element metal side wall, the current is avoided from being concentrated in the center of the dipole patch, and therefore the impedance bandwidth of the antenna is improved. The antenna has good radiation performance at 0.4 GHz, 0.5 GHz, 0.6 GHz, 0.7 GHz and 0.8 GHz, and the antenna can be widely applied to P-waveband wireless communication systems with requirements of broadband, low profile and stable performance.

The invention discloses a terahertz directional diagram reconfigurable antenna based on an RF-MEMS switch, and belongs to the technical field of terahertz radio frequency front-end devices. The antenna is composed of a radiation unit, a composite beam ohmic contact type MEMS switch, a coplanar waveguide feed structure, a microstrip transmission line, a dielectric substrate and a metal ground backboard. The antenna adopts a single-layer quartz glass substrate integrated waveguide (SIW) feed structure, excellent impedance matching with a microstrip transmission line is realized, the relative bandwidth exceeds 19%, and an MEMS switch is driven to act through direct current bias. The antenna has a relatively wide impedance bandwidth. Reconfiguration of a directional diagram is controlled through on-off of a switch, the antenna achieves-40-degree, 0-degree and + 40-degree three-beam directional switching in the 00 mode, the 01 mode and the 10 mode, the main lobe widths in the three modes are 55.61 degrees, 58.94 degrees and 98.56 degrees respectively, and wide-angle-domain coverage is supported.

The present invention discloses a ultra-wideband compact circularly polarized antenna based on a miniaturized phase shifter, belonging to the technical field of antenna engineering. The antenna of the present invention adopts the form of cascading a feeding network and a Vivaldi antenna, and has the characteristic of wide bandwidth; the broadband matching characteristic is realized by designing forms such as a metal coupling sheet, a serrated structure, and a Γ-shaped balun; a novel miniaturized ultra-wideband 90-degree phase shifter is designed by adopting a Π network and a negative group delay circuit; both the Vivaldi antenna layer and the feeding network layer adopt the PCB process, which is easy to process and has low cost. Compared with the traditional phase shifter, a 75% size reduction is achieved, and its size is 67mm * 44.5mm (0.071λ l * 0.047λ l ). At the same time, the simulation results show that the proposed circularly polarized antenna has a 10 dB impedance bandwidth of 0.32 - 1.2 GHz (3.75:1) and a 3 dB axial ratio bandwidth of 0.32 - 1.15 GHz (3.59:1).