463results about How to "Lower resonant frequency" patented technology

The invention discloses a method for improving radiation performance of an antenna. A mobile terminal is provided with a conducting piece; the conducting piece on the mobile terminal is used as a feeder line of the antenna of the mobile terminal; the conducting piece is used as a feeder line of the antenna of the mobile terminal; and the length of the feeder line is more than 90mm. The invention discloses the mobile terminal simultaneously; a mobile terminal body is provided with the conducting piece which is used as the feeder line of the mobile terminal antenna, and the length of the feeder line is more than 90mm; and the feeder line is respectively connected with a feeding point or a feeding lead of the mobile terminal antenna and an earthing point or an earthing lead of the mobile terminal antenna. In the invention, a metal piece arranged a mobile terminal machine body can not cause any influence to the antenna of the mobile terminal, and ensure the radiation performance of the antenna of the mobile terminal. The technical scheme of the invention is simple and practical.

The invention relates to a vertical and horizontal compound excitation type piezoelectric energy harvester and belongs to the technical field of new energy sources and power generation. An upper casing and a lower casing are connected through screws, a group of piezoelectric vibrators are arranged and clamped between the upper casing and the lower casing, the free ends of the piezoelectric vibrators are provided with magnets, a ball pin is connected with an inertia block through a screw rod arranged on the inertia block, a first annular magnet, a sleeve and a second annular magnet are sequentially sheathed on the screw rod, and the magnets arranged on the piezoelectric vibrators and the first annular magnet and the second annular magnet arranged on the screw rod are arranged in a way of the similar magnetic poles of the magnets, the first annular magnet and the second annular magnet being close to one another.. The invention has the advantages that the vibration energy recovery in the vertical direction and any one horizontal direction can be realized; the vertical and horizontal compound excitation type piezoelectric energy harvester is applicable to low-frequency and great-amplitude vibration environment; and in addition, the reliability is high.

The systems and methods described herein provide for a radio frequency micro-electromechanical systems switch having two or more resonant frequencies. The switch can be configured as a capacitive shunt switch having a deflectable member coupled between two electrodes over a transmission line. A first insulator can be located between one of the electrodes and the deflectable member to form a capacitive element. The deflectable member can be deflectable between an up-state and a down-state, the down-state capacitively coupling the deflectable member with the transmission line. The degree by which the deflectable member overlaps the first insulator can be adjusted to adjust the capacitance of the capacitive element and the resulting resonant frequency.

A gas ejector capable of effectively dissipating heat generated from a heater while inhibiting noise generation as little as possible, an electronic device equipped with the gas ejector, and a gas-ejecting method are offered. A gas ejector (1) according to the present invention includes a vibrator (25) and ejects gas in a form of a pulsating flow such that vibration of the vibrator allows sound waves respectively generated upon ejection of the gas ejected from nozzles (23) and (24) to deaden out each other. Also, a control section (20) optimizes the frequency of the vibrator (25), hence, by increasing the gas ejection quantity as much as possible while inhibiting noise generation, heat of a heater is effectively dissipated.

The invention discloses a loudspeaker diaphragm which comprises a ball top part (20) in the center and a folding part (10) at the rim. The folding part (10) is a single layer structure made from a TPEE (thermoplastic polyester elastomer) material layer (2) or is a composite structure provided with at least one TPEE material layer (2). Compared with diaphragms made from TPU materials, the diaphragm of the invention has good toughness and strength, can effectively reduce the vibration frequency, and expand the bandwidth of a product. Further, the diaphragm is also stable in structure and reliable in withstanding power and provides good stability of vibration frequency.

The invention discloses a Broad Band micro-strip coupler based on a defect ground structure. The Broad Band micro-strip coupler comprises a defect ground structure, a microstrip structure signal layer and ports; wherein the defect ground structure comprises a ground layer, an open ring and an interdigital line. The frequencies f0 and f1 of the defect ground structure are determined according to the technical index force factor C, the characteristic impedances Z0 of the terminals, the central frequency fc and the parameter (Epsilon r, h)of the microstrip; f0 is less than fc, and fc is less than f1(as showed in formula I) and the value of f1 / f0 is determined according to the requirement of the broad band; the size of the defect ground structure is determined according to f0, f1 and (Epsilon r, h). The width W, the distance and the length p of the coupled microstrip lines are calculated through simulation software and then are optimized to satisfy design requirements. Compared with conventional directional couplers with parallel coupled lines, the Broad Band micro-strip directional coupler added with a defect ground structure which is provided with an open ring and an interdigital line is effectively increased in work bandwidth and the defect ground structure can improve the coupling factor of the coupler.

The invention relates to a dual-crank arm type piezoelectric-electromagnetic composite power generation device. The composite power generation device comprises a dual-crank arm type piezoelectric-electromagnetic composite transducer; the dual-crank arm type piezoelectric-electromagnetic composite transducer comprises a dual-crank arm type piezoelectric-electromagnetic composite power generation oscillator, an upper permanent magnet layer, an upper induction coil layer, a lower permanent magnet layer, a lower induction coil layer and a piezoelectric-electromagnetic composite transducer box; the upper permanent magnet layer is arranged in the middle of the upper induction coil layer; the lower permanent magnet layer is arranged in the middle of the lower induction coil layer; and the dual-crank arm type piezoelectric-electromagnetic composite power generation oscillator is arranged between the upper and lower permanent magnets, and the induction coils. A dual-crank arm type piezoelectric oscillator, a permanent magnet mass block and a rigidity-variable spring of the dual-crank arm type piezoelectric-electromagnetic composite power generation oscillator form an overall structure to generate a certain synergistic effect, so that the composite power generation device is relatively low in resonant frequency and relatively high in amplitude, and generated electric quantity is obviously increased; and therefore, the composite power generation device is widely applicable to the recycling fields of random, wideband, low-frequency, high-amplitude, and high-strength vibration energy in the environments.

High-directivity microstrip antennas comprising a driven patch and at least one parasitic element placed on the same plane, operate at a frequency larger than the fundamental mode of the driven patch in order to obtain a resonant frequency with a high-directivity broadside radiation pattern. The driven patch, the parasitic elements and the gaps between them may be shaped as multilevel and / or Space Filling geometries. The gap defined between the driven and parasitic patches according to the invention is used to control the resonant frequency where the high-directivity behaviour is obtained. The invention provides that with one single element is possible to obtain the same directivity than an array of microstrip antennas operating at the fundamental mode.

A compound antenna containing two fractals belongs to the technical field of multiband small size antenna. On the basis of the traditional fractal antenna, an antenna fractal is added, the two fractal antennae form the compound antenna; wherein one fractal construction unit is taken as a feeding unit of the whole antenna; when the feeding unit obtains electromagnetic wave energy from a feed source by a feeder line, coupling current can be generated on the fractal parasitized or connected with the other fractal antenna; when the coupling current and current on the feeding unit are in the same flow direction and the same phase position, the two currents in the same flow direction lead the distant field radiation to be superimposed in phase, thus improving the radiation characteristic of the antenna, achieving the impedance matching in the frequency band near the resonance point and expanding the frequency bandwidth. The applicable frequency range of the compound fractal antenna is from UHF frequency band of hundreds of MHz to millimeter wave frequency band of dozens of GHz.

The invention discloses a multimode mixed cavity structure used in a filter. The structure comprises a resonance rod, medium gaskets, a cavity body and a cover plate, wherein the cover plate is arranged on the cavity body, the cavity body is provided with a resonance cavity with hollow inner portion, and the resonance rod is arranged in the resonance cavity. The structure is characterized in thatthe resonance rod is composed of a plurality of rods which are perpendicular to one another, the resonance rod is made from metal or metal alley or nonmetal materials with metallized surfaces, one medium gasket is arranged between at least one end portion of the resonance rod and the inner wall of the cavity body, one end of each gasket is connected to the end portion of the resonance rod, and theother end of the corresponding gasket is connected to the inner wall of the metal cavity body. The multimode mixed cavity structure used in the filter has the advantages that the structure is simple,the installation and use are convenient, and the problem that the electromagnetic field is trapped in the resonance rod, which causes difficult coupling is avoided by changing the medium resonance rod in the multimode cavity body medium resonator into the metal resonance rod or the resonance rod with a metalized surface.

The invention discloses a broadband capacitive feed miniature microstrip paster antenna. A foam dielectric substrate is arranged between a microstrip dielectric substrate and an earth plate and thus the thicknesses of the dielectric substrates are increased; and an equivalent dielectric constant is reduced and a working band width of the antenna is extended. A metal short-circuit surface is loaded at an edge of one side of a radiation paster to form a standing wave structure from an open circuit to a short circuit; and the length of the antenna at the direction perpendicular to the short-circuit surface is a quarter of a wavelength. Slotting is carried out on the radiation paster and the path of an excitation current of the surface of the antenna paster is bent, thereby increasing the effective length of the antenna paster and thus reducing the resonant frequency and realizing miniaturization of the antenna at the another-dimensional dimension. Coupling and feeding are carried out by using a capacitive paster to realize good impedance matching, thereby reducing equivalent quality factors of the antenna and realizing increasing of the operating bandwidth of the antenna. According to the invention, a defect that the existing microstrip paster antenna can not consider the wide frequency band and miniaturization simultaneously can be overcome. The provided antenna has advantages of wide frequency band, low profile, small dimension, light weight, and easy processing.

The invention relates to a composite structure piezoelectric energy collector driven by a cantilever. The energy collector comprises a cantilever member and an output unit used for output of generated electric energy output, one end of the cantilever is a fixed end which is fixed on a base, the other end of the cantilever is a free end, a pair of piezoelectric energy converting units are respectively symmetrically arranged on the portions, near the fixed end of the cantilever member, of the upper surface and the lower surface of the cantilever member, and the piezoelectric energy converting units are driven by vibration of the cantilever member to generate electric energy.

A wireless power transmission system adapted for multiload dynamic switching comprises a primary module for transmitting electric energy and a second module for picking up electric energy. The primary module transmits electric energy to the secondary module by using electromagnetic coupling resonance, and when the secondary module switches different power loads, the secondary module gradually changes, by using soft switching, a secondary reflected impedance by using a mode of gradually increasing voltages on two sides of a load, so that changes of a resonance frequency and a phase of the primary module are kept in a self-adaptive range of frequency tracking and control. The primary module can make stable adjustment according a dynamic change of the load, making the primary module stably work; in addition, for an output voltage of a system, because soft switching is used to change the load in load switching, the impact of a load change on the system resonance is reduced, and the stability of a secondary output voltage is ensured.

The embodiment of the present invention provides a Print-circuit board antenna and terminal. The Print-circuit board antenna includes a Print-circuit board and a feed-back contact disposed on the Print-circuit board. The print-circuit board is covered by a copper layer. The copper layer is provided with a slot which is communicated with the outside of the print-circuit board. The copper layer is provided with a groove which is vertical to the slot. The slot is communicated with the groove. The copper layer on the two sides of the slot forms a first antenna and a second antenna from the slot to the two ends of the groove. The feed-back contact is used for forming a first resonant circuit with the first antenna and is used for forming a second resonant circuit with the second antenna. The resonant frequency between the first resonant circuit and the second resonant circuit are different.

Present invention relates to a ultrathin dual polarization microstrip antenna. It contains radiating element, metal base plate and a pair of power feed parts, wherein two power feed parts fixed on metal base plate, each power feed part including power feed piece and connected impedance inverter circuit, said radiating element supported above two power feed parts, said radiating element having at least two V-groove, each V-groove axial symmetry distributed along radiating element center point, each V-groove angular point nearing to radiating element center point. Said V-groove prolongs current path, reducing resonant frequency, and shortening aerial size, and V-groove having restrictive effect to radiating element surface current to make most of flow along area between adjacent two V-grooves, thereby rising cross polarization ratio.

The invention relates to a microwave resonant cavity provided with an inner conductor with a helical notch groove structure, belonging to the radio frequency and microwave passive system technical field; the invention comprises an outer conductor cavity, a capacitance loading disc and an inner conductor, wherein the inner conductor which is provided with a notch groove has one end connected with the wall of the outer conductor cavity and the other end connected with the capacitance loading disc which is in parallel to an top cover of the outer conductor cavity; a metal turning plug can be inserted in the outer conductor cavity. The microwave resonant cavity adopts the structure of the inner conductor provided with the notch groove, which makes the resonance frequency of the microwave resonant cavity halved compared with other microwave resonant cavities which are the same in size; thus an aim of greatly reducing the volume of the resonant cavity is achieved.

An electric rotating machine includes a rotor and a stator. The rotor has a plurality of pairs of magnetic poles. The stator includes a stator core and a stator coil that is comprised of a plurality of phase windings wound on the stator core. The stator core has, for each of the phase windings of the stator coil, n circumferentially-consecutive single-phase slots, in which only the phase winding is received, per magnetic pole of the rotor, where n is a natural number not less than 2. Each of the phase windings of the stator coil has first to kth sections that are sequentially arranged from one end to the other end of the phase winding, where k is a natural number not less than 2. The first section is received in different ones of the single-phase slots for the phase winding from the kth section.

A telescopic speaker box, and an audio player and an electronic apparatus using the same are provided. The audio player comprises a loudspeaker unit and a telescopic speaker box. The telescopic speaker box comprises a speaker box housing whose volume is adjustable. The speaker box housing has a hole. The hole is used for receiving the loudspeaker unit. By adjusting the volume of the speaker box housing, a lowest resonant frequency of the telescopic speaker box can be achieved.

A probe for nuclear magnetic resonance (NMR) measurement provided with a multiple resonant circuit for detecting signals of two or more nuclides with high detection efficiency for nuclide at low resonant frequency comprises a multiple resonance radio frequency (RF) coil circuit that, with multiple lead lines connected to the RF coil, causes a part of the RF coil, separated by the connection points of the lead lines, to function as the inductor of a trap circuit that cuts off a signal at the frequency F1 for a signal at the resonant frequency F1 of a first nuclide and, at the same time, to function as an RF coil that detects a signal at the frequency F2 for a signal at the resonant frequency F2 of a second nuclide, thus increasing the signal detection efficiency for the nuclide at the frequency F2.

The invention belongs to the technical field of microwaves and millimeter waves and provides a dual-mode reconfigurable filter based on a half-mode substrate integrated waveguide and a CSR structure,mainly to solve the problems that an ordinary tunable filter has large insertion loss and bias voltage of a PIN diode can not be directly added to the substrate integrated waveguide. The half-mode substrate integrated waveguide technology is adopted, an upper metal pattern layer comprises a half-mode substrate integrated waveguide copper clad layer, a DC bias circuit, an epsilon-type microstrip line and other structures. Two complementary circular spiral resonators (CSR) are arranged at two sides of the copper clad layer, through applying forward / reverse bias voltage, the PIN diode is conducted or cut off, the upper metal copper and the epsilon-type microstrip line are conducted or cut off, and finally, single dual passband switching is realized. The reconfigurable filter under the features is particularly suitable for a wireless communication system, and has the advantages of small size, low insertion loss, multiple transmission zero points, high out-of-band suppression, convenient DCfeed loading, quick tuning speed, convenient tuning and the like.

The invention discloses a slit antenna, a parameter regulation method and a terminal thereof, which belong to the field of antennae. The slit antenna comprises a floor, a coupling piece and a feeding point, wherein a half-sealed notch area is formed at one side of the floor; the coupling piece is positioned in the half-sealed notch area, and slits are formed among the coupling piece and the bottom wall and the side wall of the half-sealed notch area; and the feeding point is positioned in the slit formed between the coupling piece and the side wall. The method comprises the step of regulating the size of the slit, the size of the half-sealed notch area, the size of the coupling piece and at least one in the number of the layers of the coupling piece so as to obtain a corresponding resonant frequency and a corresponding bandwidth. The terminal comprises the slit antenna. The invention enables current to be evenly distributed on the floor, has better property of omnidirectional radiation, smaller antenna size and smaller occupied area of a basal plate and can retain more areas for arranging other components.

The invention discloses a high-efficiency photovoltaic grid connected inverter, and belongs to the technical field of power electronic converters. The high-efficiency photovoltaic grid connected inverter comprises a DSP controller, a first MOS pipe, a second MOS pipe, a transformer, a driving circuit, sampling circuits, an inductor, capacitors and a load, wherein the transformer comprises a primary winding and two secondary windings. In the field of photovoltaic power generation, a DC-DC conversion part is a key part of the inverter; at present, a DC-DC conversion part adopts a hard switching technology generally, so that the electric energy conversion efficiency is too low, and meanwhile, since voltage stress and current stress in a circuit are too high, relatively strong electromagnetic interference is caused. Therefore, an LLC resonant conversion technology is adopted, self parasitic parameters of components are fully used, the voltage stress and the current stress are reduced, a switching frequency can be equal to a resonant frequency, and the conversion efficiency is improved. The high-efficiency photovoltaic grid connected inverter is especially suitable for being used on occasions where requirements on the efficiency of the inverter are relatively high.

The invention discloses a microstrip antenna, an OBU of an ETC system, and an electronic device. The microstrip antenna comprises a radiation patch, a metal surface and a feed network feeding the radiation patch, wherein the radiation patch is provided with two patch slots which are vertically crossed to form a cross, and each patch slot is also provided with an auxiliary slot communicating therewith. The radiation patch provided by the invention enables the antenna to have relatively wide bandwidth and relatively high gains under the feeding effects of dual feed points of the feed network, and excellent circular polarization performance is also exhibited, at the same time, by increasing the flow paths of current on the radiation patch, the microstrip antenna may still satisfy the requirements for working frequency even when the size is reduced, and therefore, the space that the microstrip antenna occupies is saved.

The invention discloses a dual-mode bi-pass filter based on capacitance loading square resonant rings, mainly solving the problems of poor out of band rejection and uncontrollable coupling between cavities of traditional bi-pass filters. The filter comprises a micro-strip dielectric substrate (11), a metal earth plate (12), two same capacitance loading square resonant rings (13), a perturbation metal sheet (16) and a pair of input / output feeder lines (17). A symmetrical cascade mode is adopted between the capacitance loading square resonant rings (13), each capacitance loading square resonant ring comprises one square metal ring (14) and four loading metal sheets, and a pair of input / output feeder lines (17) adopt a symmetrical distribution mode, are arranged mutually parallel above the micro-strip dielectric substrate (11), and penetrate into the insides of the square resonant rings (13) for feeding. The dual-mode bi-pass filter based on capacitance loading square resonant rings can improve the out of band transmission characteristic, control the strength of coupling between cavities, realize highly symmetrical bi-pass frequency response, and be used in a wireless communication system.

The invention provides a low-band frequency selective surface with minimized cell sizes. The low-band frequency selective surface comprises a printed circuit board (PCB). An upper conductive layer is arranged on the front surface of the PCB, and a lower conductive layer is arranged on the back surface of the PCB. The upper conductive layer consists of upper periodical cells which are periodically arranged. The lower conductive layer consists of lower periodical cells which are periodically arranged. The upper and lower periodical cells are provided with vertically aligned conducting strips which are surface-surface coupled to form high distributed capacitance to reduce the resonance frequency of the frequency selective surface. The more than 20*20 upper periodical cells correspond to the lower periodical cells. According to the frequency selective surface, the vertically aligned conducting strips are arranged in the upper and lower conductive layers, and are surface-surface coupled to form the high distributed capacitance, so that the resonance frequency of the frequency selective surface is remarkably reduced. The frequency selective surface is insensitive to the polarization characteristics of electromagnetic waves, and the passband characteristics of different polarized electromagnetic waves (transverse electric (TE) waves and transverse magnetic (TM) waves) are substantially the same.

The invention discloses a vibration energy collector. The collector comprises a piezoelectric cantilever beam and a mass block. The piezoelectric cantilever beam comprises a main beam which is transversely arranged, a plurality of first auxiliary beams which are vertically arranged and a plurality of second auxiliary beams which are vertically arranged. One end of the main beam is a fixed end. The other end of the main beam is a free end. The mass block is fixed to the free end of the main beam. The plurality of first auxiliary beams are arranged with intervals and are fixed to one side of the main beam. The plurality of second auxiliary beams are arranged with intervals and are fixed to the other side of the main beam. By using the vibration energy collector, the main beam of the piezoelectric cantilever beam is provided with the plurality of first auxiliary beams and the plurality of second auxiliary beams; each auxiliary beam possesses a respective resonant frequency and resonant frequency points of the vibration energy collector are increased; and when each auxiliary beam generates vibration, voltage attenuation of two sides of each resonant frequency point is slow so that a bandwidth is increased. Simultaneously, through the auxiliary beams, an electricity production area is correspondingly increased, output electric energy is improved and a problem that a frequency point energy density is low is solved.

The invention discloses a bionic hair-type silicon micro-gyroscope for angular velocity sensing. The bionic hair-type silicon micro-gyroscope is composed of upper polymer hair, a middle silicon micro-sensor and a bottom glass substrate equipped with a circuit, wherein the middle silicon micro-sensor comprises a circular mass block and an annular mass block with a same circle center as the circular mass block; two torsion beams are arranged between the circular mass block and the annular mass block; the upper polymer hair is adhered onto the center of the circular mass block; and the circumferential lateral part of the annular mass block are uniformly provided with a plurality of comb groups and square wave supporting beams which are arranged in a staggered way. The bionic hair-type silicon micro-gyroscope is novel in structure, has high sensitivity and is compatible with conventional planar process; and compared with a simple conventional planar structure, the arrangement of the upper polymer hair is favorable for enlarging the Coriolis effect and improving structure sensitivity.