51results about How to "Broaden the bandwidth of the frequency band" patented technology

A contact structure for establishing electrical connection with contact targets. The contact structure is formed of a contactor carrier and a plurality of contactors attached to a contactor carrier. The contactors are inserted in diagonal through holes on the contactor carrier and attached to the contactor carrier through adhesives. The contactor has a top end having a flat top surface, a straight diagonal beam integral with the top end and configured by an upper beam portion and a lower beam portion, and a lower end at an end of the lower beam portion to contact with a contact target. A length of the upper beam portion and a length of the lower beam portion are about the same. A probe contact assembly using the contact structure is also disclosed which incorporates a flip chip bonding technology to interconnect the components therein.

The invention, suitable for the field of mobile communication base station antenna, discloses a wideband double frequency mobile communication base station antenna, which comprises a low frequency radiation unit array, a high frequency radiation unit array, a low frequency feed network, a high frequency feed network and a reflection plate. The low frequency unit enhances bandwidth by introducing parasitic radiation patch. Tail ends of two pairs of radiation arms of the high frequency radiation unit are bent, the high frequency radiation unit array is nested in blank region remained by the lowfrequency radiation unit, and the radiation unit array is fixed axially to the reflection plate. The high and low frequency radiation units are etched on the same surface of medium base plate of antenna radiation body, and L-shaped coupled micro-strip feed lines are etched on the other surface of the medium base plate of the antenna radiation body. High and low frequency micro-strip power dividers disposed on the reflection plate are connected with the high and low frequency radiation units respectively through a coaxial line, each signal is input to the radiation unit corresponding to each array in uniform amplitude and constant phase way, and such symmetrical feed mechanism ensures that the antenna can obtain good directional diagram property.

An embodiment of the invention discloses a terminal antenna and an intelligent terminal. The terminal antenna comprises a first antenna, a first feed source, a first matching circuit, a first switch, a second matching circuit and a third matching circuit, wherein a first port of the first antenna is connected with the first feed source through the first matching circuit; the first matching circuit is used for matching the first antenna; the second matching circuit comprises a plurality of matching channels and is used for spreading a spectrum of a high frequency band of the first antenna; a second port of the first antenna is connected with the plurality of matching channels of the second matching circuit through the first switch; a third port of the first antenna is connected with a third matching circuit; the third matching circuit is used for spreading a spectrum of a low frequency band of the first antenna. With adoption of the scheme of the embodiment, overall space of the terminal is reasonably used, and multi-frequency band and large bandwidth of the antenna in the terminal are realized.

An internal planar antenna for small radio apparatuses, and a radio apparatus. The ground plane (310) of the planar antenna is shaped such that it improves the matching of the antenna. The shaping may be done by means of one or more slots (315, 316) in the ground plane. The slot suitably changes the electrical length of the ground plane as viewed from the short-circuit point (S) so that the ground plane will function as a radiator in an operating band of the antenna. Also the slot (331) in the ground plane can be arranged to function as an additional radiator in an operating band of the antenna. Antenna gain will increase as the matching is improved, and the upper band of a dual band antenna, for example, can be made broader.

The invention discloses a globally universal ultra-high frequency radio frequency identification device (RFID) reader antenna. The globally universal ultra-high frequency RFID reader antenna is characterized by comprising a laminated panel antenna, a horizontally wound plate and an input connector, wherein the laminated panel antenna comprises an upper radiant panel, a lower radiant panel and a floor plate from top to bottom; the horizontally wound plate is fixed between the lower radiant panel and the floor plate; one end of the horizontally wound plate is connected with the lower radiant panel through a feed probe I, while the other end is connected to a conductor in the input connector through a feed probe II; the upper radiant panel, the lower radiant panel, the horizontally wound plate and the floor plate are sequentially fixed through fixing screws; and air clearances are reserved among the upper radiant panel, the lower radiant panel, the horizontally wound plate and the floor plate through shaft sleeves arranged at the position of the fixing screws. Through horizontally wound plate feed technology and laminated panel configuration, the antenna circular polarization bandwidth and the input voltage standing wave ratio are low, the processing is simple and the cost is low. Therefore, the globally universal ultra-high frequency RFID reader antenna is applied to an ultra-high frequency RFID system in any country or region in the world.

The invention discloses an ultra-wideband absorber based on a combined resonant structure, and a manufacturing method thereof. The ultra-wideband absorber includes a dielectric layer, a film, a firstresonant structure and a second resonant structure, wherein the dielectric layer is provided with two end faces away from each other; the film is laid on one end surface of the dielectric layer; the first resonant structure is mounted on the other end surface of the dielectric layer and includes two first resonant units disposed opposite to each other; the first resonant units are L-shaped, and anopening ring structure is formed through enclosure of the two first resonant units; the second resonant structure is mounted on the other end face of the dielectric layer and is located in the opening ring structure; the second resonant structure includes two second resonant units each in a square shape; and the two second resonant units are partially overlapped. The ultra-wideband absorber basedon a combined resonant structure enables the waveforms absorbed by the first resonant structure and the second resonant structure to be linearly superimposed to form an absorbing band having a plurality of harmonic absorption peaks, thus breaking the constraint of the original two bandwidth expansion methods, and reducing the time and the cost of device construction.

A wireless cellular communication system in which groups of cellular base stations communicate with a central office via a narrow-band millimeter wave trunk line. The transceivers are equipped with antennas providing beam divergence small enough to ensure efficient spatial and directional partitioning of the data channels so that an almost unlimited number of transceivers will be able to simultaneously use the same millimeter wave spectrum. In a preferred embodiment the trunk line communication link operates within the 92 to 95 GHz portion of the millimeter spectrum. A large number of base stations are each allocated a few MHz portion of a 900 MHz bandwidth of the millimeter wave trunk line. A first transceiver transmits at a first bandwidth and receives at a second bandwidth both within the above spectral range. A second transceiver transmits at the second bandwidth and receives at the first bandwidth. Antennas are described to maintain beam directional stability to less than one-half the half-power beam width. In a preferred embodiment the first and second spectral ranges are 92.3–93.2 GHz and 94.1–95.0 GHz and the half power beam width is about 0.36 degrees or less. Thus, in this system the low frequency band width is efficiently utilized over and over again by dividing a territory into small cells and using low power antenna. And a higher frequency bandwidth is efficiently utilized over and over again by using transmitting antennae that are designed to produce very narrow beams directed at receiving antennae. In a preferred embodiment cellular base stations are prepackaged for easy quick installation at convenient locations such as the tops of commercial buildings.

The invention relates to an integrated substrate wave-guide bandpass filter based on a triangular complementary split-ring resonator. The integrated substrate wave-guide bandpass filter comprises a resonant cavity in equilateral triangle, the resonant cavity is composed of an upper surface metal layer, a medium substrate and a lower surface metal grounding plate stacked in order; the upper metal layer is communicated with the lower surface metal grounding plate through the bottom metal column after penetrating the medium substrate; and a triangular complementary split-ring resonator is arranged at a center location of the upper surface metal layer, wherein the triangular complementary split-ring resonator is loaded in a pair of triangular resonant cavities in a degenerate mode, the complementary split-ring resonant can product a passband, the produced passband is modulated to a pair of degenerate modes by regulating the parameter of the ring resonator, thereby improving the bandwidth of the filter. The transmission zero point of the bandpass filter can be further adjusted by opening a round interference metal hole in the resonant cavity, thereby effectively inhibiting the out-of-band harmonic. The bandpass filter disclosed by the invention is not only simple in structure, convenient for processing, but also can effectively inhibit the out-of-band harmonic since the transmissionzero-points are coexistent in the low-frequency end and the high-frequency end, the high frequency selectivity and excellent performance are provided.

The invention belongs to a magnetic antenna for high-speed aircraft navigation and communication, which comprises a columnar spiral antenna, a closed antenna cover, a strong magnet ground plate and a conical coaxial feeding wire column. In the magnetic antenna, the spiral antenna of an axial mode is adopted, the antenna and a strong permanent magnet are integrated, the magnet serves as a magnetic field generator to generate a high permanent field and also serves as the antenna ground plate, when magnetic field intensity B is more than or equal to 0.5T, signal emitted by the spiral antenna can effectively penetrate a plasma, when the magnetic field of the permanent magnet is increased to 1.0T, antenna gain is increased to 9.6dB and approaches 10.6dB of the antenna gain in air, and the attenuation of electromagnetic wave during transmission in the plasma is reduced by 30dB. Therefore, the magnetic antenna has the characteristics of frequency bandwidth, circular polarization bandwidth, low attenuation amplitude of the electromagnetic wave of the antenna and the like, the antenna gain and the penetrability of the plasma are effectively improved, and the defect of communication interrupt caused by the existence of a surface plasma sheath in a background technology is overcome.

The invention discloses a composite hydraulic system broad-spectrum fluid pressure pulsation attenuator. The two ends of a shell are provided with a front end cap and a rear end cap. A small-diameter inner pipe, a large-diameter inner pipe and a fluid attenuation assembly are fixedly mounted in the portions, between the front end cap and the rear end cap, of the shell. The two ends of the small-diameter inner pipe separately communicate with a fluid inlet and a fluid outlet. The pipe walls of the small-diameter inner pipe and the large-diameter inner pipe are both provided with damping holes. The fluid attenuation assembly comprises circular hole screen heads arranged at the two ends of the small-diameter inner pipe, a mesh enclosure particle assembly arranged in the small-diameter inner pipe and an elastic string barrel arranged between the small-diameter inner pipe and the large-diameter inner pipe. By adoption of the composite hydraulic system broad-spectrum fluid pressure pulsation attenuator, pulsation energy can be effective attenuated in the mode that a dissipation system and a mass-spring system are combined, fluid is guided to flow, the transmission speed is greatly decreased to control fluid fluctuation, the pulsation amplitude of the pressure fluid flowing through the attenuator is effectively and greatly decreased, the frequency bandwidth of pulsation attenuation is further broadened, broad spectrum and maximization of the attenuation effect are achieved, and the double-filtering effect of structure resonance and fluid resonance is achieved.

The invention discloses an on-chip integrated broadband linearizer based on a variable capacitor, and belongs to the technical field of microwave and millimeter wave monolithic circuits. A linearizedcircuit control module is used for controlling a direct-current voltage drive provided for a reflective pre-distortion signal generator and a cold-mode pHEMT transistor compensation correction circuit, so as to adjust the size of the generated linearized signal. Then, a reflective pre-distortion signal generator and a cold mode pHEMT transistor compensation correction circuit are combined; the pre-distortion signals are generated and compensated, pre-distortion linearized signals are finally generated to counteract nonlinearity of the power amplifier, and the reflective pre-distortion signal generator and the cold mode pHEMT transistor compensation correction circuit are matched with a low-loss matching module to further reduce insertion loss. According to the broadband linearizer, the problem that a traditional linearizer cannot be applied to a broadband is solved, and the bandwidth is better broadened. The filter has the characteristics of low insertion loss, wide application bandwidth, compact structure and remarkable linearization improvement.

The invention discloses an S-band high-gain circularly polarized antenna, which comprises at least one antenna unit, a supporting column and a feed network, wherein the antenna unit comprises four rotationally symmetric antenna oscillators, the top parts of the four antenna oscillators are separated, the bottom parts thereof are connected, a plurality of grooves are formed in each antenna oscillator, the supporting column is connected with the four antenna oscillators, the supporting column is further connected with a metal bottom plate, and the feed network is used for feeding the antenna oscillators. According to the S-band high-gain circularly polarized antenna, a butterfly antenna is realized through separating the top parts of the four antenna oscillators and connecting the bottom parts thereof, a fractal antenna is realized through forming the plurality of grooves in each antenna oscillator, and the butterfly antenna is combined with the fractal antenna, such that the frequency bandwidth is effectively expanded, the structure is simple and the cost is low.

The invention discloses a shear stress sensor based on 1-3 type cement-based piezoelectric composites and a preparation method thereof. The shear stress sensor comprises a 1-3 type cement-based piezoelectric composite component; and a packaging layer and a shielding layer with which the 1-3 type cement-based piezoelectric composite component is wrapped in sequence. Positive and negative electrodesof the 1-3 type cement-based piezoelectric composite component are led out of the shielding layer through a wire to be connected with a shielding wire. The shielding wire is connected with the shielding layer. The component comprises a cement-based piezoelectric composite body and an electrode. The cement-based piezoelectric composite body is composed of a piezoelectric ceramic column array formed by piezoelectric ceramic columns and a cement base material filled among the piezoelectric ceramic columns. The piezoelectric ceramic column array is obtained by cutting a polarized piezoelectric ceramic block with the cutting direction perpendicular to the polarization direction of the piezoelectric ceramic block. The sensor of the invention has the advantages of high sensitivity, wide frequency response, good anti-interference effect and good compatibility with a concrete structure, and can be used for the health monitoring of the concrete structure.

The invention discloses a BeiDou microstrip antenna loaded with wrench type resonant rings and relates to a microstrip antenna. The BeiDou microstrip antenna is provided with a medium substrate, upper and lower surface good conductor layers and a coaxial feed structure; the upper and the lower surface good conductor layers are respective coated at upper and lower surfaces of the medium substrate; the upper surface layer is a square patch which is arranged on the middle of the medium substrate; two wrench type resonant rings are symmetrically loaded at a pair of opposite angles of the square patch; each wrench type resonant ring consists of an isosceles-right-triangle-shaped cut corner, a rectangular gap and a circular ring notch groove; the vertex of the isosceles-right-triangle-shaped cut corner is superposed with the vertexes of the selected loading opposite angles; two right-angle sides of the isosceles-right-triangle-shaped cut corner are positioned on two sides, jacked out from the vertexes,. of the square patch; one short side of the rectangular gap is superposed with the inclined side of the isosceles-right-triangle-shaped cut corner; the other short side of the rectangular seam is a chord of the outer circle of the circular ring notch groove; the circle center of the circular ring notch groove is positioned in a position, on a diagonal line of the group of the selected loading opposite angles, of the square patch; and a coaxial inner conductor in the coaxial feed structure is connected with the square patch.

The invention discloses an orthotropic piezoelectric sensor for monitoring / detection of a civil engineering structure. The orthotropic piezoelectric sensor for monitoring / detection of the civil engineering structure comprises an orthotropic piezoelectric composite material component, a matching layer, a back-lining layer and a wire, wherein the lower surface of the orthotropic piezoelectric composite material component is connected with the matching layer, other surfaces of the orthotropic piezoelectric composite material component are connected with the back-lining layer, the surface of the matching layer and the surface of the back-lining layer are respectively provided with a shielding layer in a coating mode, and the wire is respectively connected with a positive electrode and a negative electrode of the orthotropic piezoelectric composite material component. The invention further discloses a preparation method of the orthotropic piezoelectric sensor for monitoring / detection of the civil engineering structure, and application of the orthotropic piezoelectric sensor for monitoring / detection of the civil engineering structure. The orthotropic piezoelectric sensor for monitoring / detection of the civil engineering structure has the advantages of being obvious in orthotropic characteristic, good in sensitivity, wide in response frequency band, good in disturbance-resisting capacity, capable of having different response characteristics aiming at different directions, and capable of effectively restraining reception of sidewise interference signals, and improving a signal-to-noise ratio.

The invention discloses a wide band induction heating power supply based on resonance frequency tracking. The wide band induction heating power supply comprises a rectifier filter circuit, a full-bridge inverter circuit, an impedance matching transformer, a resonant circuit, a zero-crossing comparing circuit, a full-digital frequency tracking controller and a full-bridge driving circuit; the full-digital frequency tracking controller is composed of a digital phase discriminator, a digital filter and a digital oscillator; the digital phase discriminator is composed of a shaping filter and a phase comparator; and the digital oscillator is composed of a phase difference frequency word controller, a reference frequency word controller, a phase angle threshold controller, a frequency word controller and a direct digital synthesizer. The wide band induction heating power supply adopts the full-digital frequency tracking controller and has the characteristics of quick resonance frequency search, wide frequency band and high precision; and the wide band induction heating power supply adopts the shaping filter to conduct shaping on signals representing the load voltage and the current phase, the influence of high-frequency jitter noise on the phase comparator is reduced, and the anti-jamming ability of a system is enhanced.

The invention provides a planar antenna array. The planar antenna array comprises multiple open waveguide units and waveguide signal transmission channels; each signal transmission channel is equipped with a multi-stage one-to-two power distribution network, and adopts a reflective structure which consists of multiple slowly-changed stage structures and slowly-changed stages; the open waveguide units, waveguide openings, a first polarized selection cavity, a second polarized selection cavity, a first polarized connecting opening, and a second polarized connecting opening are combined with multiple stage structures and interference convex structures, so as to effectively realize impedance conversion and impedance matching and expand frequency band bandwidth; in addition, the requirement on the manufacturing precision is relatively low, and the manufacturing cost is even lower; in addition, the invention provides a polar antenna with a polarization regulation function on the basis; the polar antenna comprises the polar antenna array with the above-mentioned structure, and a polarization regulation apparatus; the polarization regulation apparatus comprises a polarization synthesizer and a polarization receiving-transmitting device, wherein the common ports of the polarization synthesizer and the polarization-taking device are directly connected; and the polarization-taking device rotates along an axial line, and realizes dual-polarization receiving-transmitting and sharing through a minute quantity of microwave reactive devices.

Systems and methods are provided for reducing interference when optical signals are added. One embodiment includes a method for adding an optical channel for communicating data and having a bandwidth within an optical spectrum for transmission along an optical link of an optical network. The method includes creating a lower frequency holding zone having a lower frequency bandwidth adjacent to the bandwidth of the added optical channel and including at least one lower frequency sub-slice having a power spectral density that varies throughout the lower frequency sub-slice. Also, the method includes creating a higher frequency holding zone having a higher frequency bandwidth adjacent to the bandwidth of the added optical channel and including at least one higher frequency sub-slice having a power spectral density that varies throughout the higher frequency sub-slice. The lower frequency holding zone and the higher frequency holding zone are dynamically configured with respect to fiber and channel requirements.

A phase-locked loop circuit reference stray elimination method, elimination device and phase-locked loop system are disclosed; wherein the phase-locked loop circuit comprises a phase frequency detector, a loop filter and a voltage-controlled oscillator which are sequentially coupled, the elimination device comprises a frequency detection unit, a controller and a notch filter, wherein the frequency detection unit is suitable for detecting real-time reference frequency input to the phase frequency detector to obtain a reference frequency detection value; the controller is suitable for obtaining a reference frequency reference value, obtaining a control parameter adjustment value corresponding to the notch filter according to the reference frequency reference value and the reference frequency detection value, and adjusting an electrical parameter value of the notch filter according to the control parameter adjustment value, thereby enabling the center frequency value of the notch filter to be the same as the reference frequency detection value; and the notch filter is arranged between the loop filter and the voltage-controlled oscillator, and the electrical parameter value of the notch filter is adjustable. According to the scheme, the reference stray elimination effect can be improved.

A dual band helical antenna with wide bandwidth includes a straight section and a helical tail section having a first and a second coil length, respectively. The straight section has a signal feed point located at a lower end thereof being connected to a signal source for feeding in an antenna signal. The first coil length determines a high-frequency resonant frequency of the dual band helical antenna, and a total length of the first and the second coil length determines a low-frequency resonant frequency of the dual band helical antenna. The straight section includes a diametrically expanded section to increase a high-frequency bandwidth of the dual band helical antenna.

The invention discloses a preparation method of a total stress sensor based on cement-based piezoelectric composite material components. The preparation method comprises the following steps: step one,preparing first to third type cement-based piezoelectric composite material components of d15 mode, namely d15 mode components; step two, preparing first to third type cement-based piezoelectric composite material components of d33 mode, namely d33 mode components; step three, using the d15 mode components and the d33 mode components to prepare the total stress sensor, namely comprising the stepof uniformly distributing one d33 mode component and one d15 mode component on every face of three adjacent surfaces of a cement base respectively, wherein the polarization directions of the three d15mode components are vertical to one another, and the polarization directions of the three d33 mode components are also vertical to one another. The total stress sensor prepared in the invention is high in sensitivity, high in frequency band response, good in anti-interference effect and good in compatibility with a concrete structure. The total stress sensor is buried into the interior of the concrete structure or adhered to the surface of the concrete structure, and simultaneously, the total stress of the concrete structure can be measured.

A wireless cellular communication system in which groups of cellular base stations communicate with a central office via a narrow-band millimeter wave trunk line. The transceivers are equipped with antennas providing beam divergence small enough to ensure efficient spatial and directional partitioning of the data channels so that an almost unlimited number of transceivers will be able to simultaneously use the same millimeter wave spectrum. In a preferred embodiment the trunk line communication link operates within the 92 to 95 GHz portion of the millimeter spectrum. A large number of base stations are each allocated a few MHz portion of a 900 MHz bandwidth of the millimeter wave trunk line. A first transceiver transmits at a first bandwidth and receives at a second bandwidth both within the above spectral range. A second transceiver transmits at the second bandwidth and receives at the first bandwidth. Antennas are described to maintain beam directional stability to less than one-half the half-power beam width. In a preferred embodiment the first and second spectral ranges are 92.3-93.2 GHz and 94.1-95.0 GHz and the half power beam width is about 0.36 degrees or less. Thus, in this system the low frequency band width is efficiently utilized over and over again by dividing a territory into small cells and using low power antenna. And a higher frequency bandwidth is efficiently utilized over and over again by using transmitting antennae that are designed to produce very narrow beams directed at receiving antennae. In a preferred embodiment cellular base stations are prepackaged for easy quick installation at convenient locations such as the tops of commercial buildings.

The invention relates to a dynamic polarization regulator, which belongs to the technical field of polarization regulation, and solves the problem that two functions of linear polarization electromagnetic wave polarization direction invariance or cross polarization conversion cannot be realized through one regulator in the prior art. The dynamic polarization regulator comprises m*n primitive cellswhich are periodically arranged, wherein m represents the number of rows, n represents the number of columns, and m and n are greater than or equal to 2. Each primitive cell further comprises a metalresonance unit which is used for enabling electromagnetic waves transmitted by the metal resonance unit to be coupled after the metal resonance unit is powered on and acquiring linear polarization waves with the polarization direction invariance or linear polarization waves with the polarization direction subjected to cross polarization conversion, dielectric units which are arranged among the metal layers of the metal resonance unit and are used for providing support for the metal resonance unit and changing the electromagnetic polarization capability of the metal resonance structure, and aregulation unit which is used for controlling the electrification and the electrification direction of the metal resonance unit. Broadband and high-efficiency electromagnetic wave regulation can be carried out, the structure is simple, manufacturing is easy, and the cost is low.

A spectral simulation method during a noise testing for a magnetic head, includes steps of (a1) detecting several first noise profiles for several magnetic head samples under a first frequency bandwidth range by a dynamic testing machine; (b1) separating each first noise profile into at least two noise curves including a first noise curve and a second noise curve at a predetermined frequency bandwidth, wherein the first noise curve has a frequency bandwidth range lower than that of the second noise curve; (c1) fitting several mathematical equations according to the second noise curves; and (d1) establishing a correlative equation among the mathematical equations, so as to simulate the second noise curve for each magnetic head. The present invention can simulate a second noise curve of the noise profile in a higher frequency bandwidth and establishing the correlative equation according to the second noise curve.

A high-isolation symmetrical folding short-circuit dipole two-unit MIMO antenna comprises two symmetrically-arranged folding short-circuit dipole antenna units and a dumbbell-shaped grounding metal isolator, and the two folding short-circuit dipole antenna units are located at the two sides of the grounding metal isolator respectively, are symmetrical about the central connecting line of a vertical arm of the grounding metal isolator and share one rectangular dielectric substrate. The port isolation degree of the two folding short-circuit dipole antenna units is improved to 20 dB or above through the dumbbell-shaped grounding metal isolator, a planar dipole antenna serves as a basic antenna structure, the two arms of the dipole antenna are folded, and the two arms are short-circuited through the metallized through holes, so that the frequency band width of the antenna is expanded, an antenna far-field radiation pattern is improved, and the antenna far-field radiation efficiency is improved. According to the invention, the antenna complexity is reduced, the bandwidth is expanded, the energy radiation is uniform, and the radiation efficiency of the antenna is improved.

The invention relates to the field of communication, and discloses an antenna system and a mobile terminal. The antenna system comprises a first antenna radiation part, a second antenna radiation partand a circuit board, wherein the circuit board is provided with a first radio frequency switch, a second radio frequency switch, a first matching circuit, a second matching circuit, a feeding point,a first grounding point and a second grounding point, the feeding point is electrically connected with the first antenna radiation part so as to achieve feeding of the first antenna radiation part, one end of the first radio frequency switch is electrically connected to the first grounding point, the other end of the first radio frequency switch is connected to the first antenna radiation part byconnecting the first matching circuit so as to achieve grounding of the first antenna radiation part, one end of the second radio frequency switch is electrically connected to the second grounding point, the other end of the second radio frequency switch is connected to the second antenna radiation part by connecting the second matching circuit so as to achieve grounding of the second antenna radiation part, and the second antenna radiation part and the first antenna radiation part are arranged at intervals to achieve electromagnetic coupling. The antenna system and the mobile terminal, provided by the invention, have wide frequency band and high performance and are simultaneously low in implement cost.

An antenna assembly for a wireless device includes an antenna cable having a feed line and a ground shield and a substrate. The antenna includes a low band ground terminal, a low band feed terminal, a high band ground terminal and a high band feed terminal. The low band ground terminal is electrically coupled to the ground shield of the antenna cable and capacitively coupled to the feed line of the antenna cable. The low band feed terminal is electrically coupled to the feed line of the antenna cable. The high band ground terminal is electrically coupled to the ground shield of the antenna cable and capacitively coupled to the feed line of the antenna cable. The high band feed terminal is electrically coupled to the feed line of the antenna cable. The low band ground terminal and the high band ground terminal are ground plane independent.

The invention relates to a high-sensitivity wide-frequency-response all fiber microseism monitoring system, and belongs to the fields of fiber sensing and safety monitoring. The system is composed of a laser light source, a fiber coupler, a sensing probe and a signal demodulator; the sensing probe comprises a packaging casing, a top cover, the fiber coupler, a reference arm fiber, a sensing arm fiber as well as a sensing arm energy transducer, a mass block, a reference arm energy transducer, a pad, a nut, a reference arm reflector and a sensing arm reflector positioned in the middle of the bottom of the packaging casing and fixedly connected in the concentric upward way; the sensing probe is filled with oil liquid; and the magnitude of a stress applied to the pad is adjusted via the nut. The system has the advantages including high detection sensitivity, smooth frequency response curve, intrinsic safety and wide application range, can obtain microseism signal of lower magnitude and wider frequency band without damage, and is suitable for safety monitoring for different types of mines and infrastructures.

The invention provides a dual-polarization FAD radiation unit, which comprises an upper feed connecting sheet, a lower feed connecting sheet, a dielectric fixing piece, a radiator and a feed connecting base, wherein the outer contour of the radiator comprises a plurality of radiating surfaces; the interior of each radiating surface is hollowed out, each hollowed-out part is of a hollow structure composed of an upper arc surface and a lower arc surface, and a circular through hole is formed in the middle of each arc surface; the radiator is fixed on the feed connecting base; the upper feed connecting sheet and the lower feed connecting sheet are embedded in the dielectric fixing piece; and the dielectric fixing piece is arranged in the through hole of the feed connecting base together withthe upper feed connecting sheet and the lower feed connecting sheet which are embedded on the dielectric fixing piece. According to the invention, the eyeball-shaped hollow holes are adopted in the radiation element, the circuit path of the radiation surface is increased, the bandwidth of the frequency band is expanded, and the standing wave and the isolation degree in the frequency band are improved, so that the size of the radiation element is relatively reduced, the assembly is simple, and the welding is convenient.

The invention discloses an orthotropic piezoelectric sensor for monitoring / detection of a civil engineering structure. The orthotropic piezoelectric sensor for monitoring / detection of the civil engineering structure comprises an orthotropic piezoelectric composite material component, a matching layer, a back-lining layer and a wire, wherein the lower surface of the orthotropic piezoelectric composite material component is connected with the matching layer, other surfaces of the orthotropic piezoelectric composite material component are connected with the back-lining layer, the surface of the matching layer and the surface of the back-lining layer are respectively provided with a shielding layer in a coating mode, and the wire is respectively connected with a positive electrode and a negative electrode of the orthotropic piezoelectric composite material component. The invention further discloses a preparation method of the orthotropic piezoelectric sensor for monitoring / detection of the civil engineering structure, and application of the orthotropic piezoelectric sensor for monitoring / detection of the civil engineering structure. The orthotropic piezoelectric sensor for monitoring / detection of the civil engineering structure has the advantages of being obvious in orthotropic characteristic, good in sensitivity, wide in response frequency band, good in disturbance-resisting capacity, capable of having different response characteristics aiming at different directions, and capable of effectively restraining reception of sidewise interference signals, and improving a signal-to-noise ratio.