107results about How to "Change working frequency" patented technology

The invention discloses a compact relativity backward wave oscillator (RBWO) with an adjustable low-frequency-range frequency, and the oscillator provided by the invention is used for solving the problems that the RBWO size in a low frequency range is great, and the output microwave frequency is hard to adjust. The compact RBWO is in rotational symmetry with respect to a central axis, and composed of a cathode base, a cathode, an anode outer barrel, a stop neck, a slow wave structure, an inner conductor, a collector, a microwave output port, a solenoid field, two rows of supporting rods, a mode converter, a radiation port and a sealing plate; the slow wave structure is composed of five slow wave blades, the inner surface of each slow wave blade is in a trapezoid structure; the left end face of the collector is provided with an annular groove; the left end of the mode converter is cylindrical, and the right end of the mode converter is in a tapered structure; the radiation port is cylindrical, the left end of the radiation port is in a tapered structure and the right end of the radiation port is cylindrical; the sealing plate is pressed on the radiation port; and the frequency of the output microwave is adjusted by virtue of adjusting the semi-diameter R3 of the inner conductor. The compact RBWO has the advantages of compact structure and convenient and adjustable work frequency, thereby being beneficial to outputting a long pulse of the microwave.

The invention discloses a multi-band frequency antenna with a cavity-backed type half-mode substrate integrated waveguide and bent slots. The multi-band frequency antenna comprises a feed microstrip line with the gradually varied widths and the cavity-backed type half-mode substrate integrated waveguide, wherein the cavity-backed type half-mode substrate integrated waveguide is provided with two rows of orthogonal metalized through holes; one or an even number of slots shaped like a Chinese character 'ji' are formed in a resonant cavity of the cavity-backed type half-mode substrate integrated waveguide; the even number of slots are connected and are symmetrical left and right; the opening direction of the slots is perpendicular to the long edge of a medium substrate. The multi-band frequency antenna has the advantages that the bent slots are adopted to play a role in changing current and field distribution of the antenna so as to change impedance matching of the antenna and especially change impedance matching of a low-frequency stage. The working frequency of the antenna is changed by changing the number of the bent slots. A large metal cavity in a cavity-backed type antenna is replaced with the two rows of metalized through holes and metal layers on the upper surface and the lower surface of the medium substrate, so that the size of the antenna decreases.

The invention discloses a composite film-based frequency-adjustable surface acoustic wave gyro, which comprises a magnetostrictive substrate, a piezoelectric film, a surface acoustic wave resonator, a surface acoustic wave detector, a metal dot matrix, a phase-shift network and a radio-frequency amplifier. The piezoelectric film is covered on the magnetostrictive substrate; the surface acoustic wave resonator, the surface acoustic wave detector and the metal dot matrix are arranged on the surface of the piezoelectric film; the surface acoustic wave resonator, the phase-shift network and the radio-frequency amplifier form a surface acoustic wave oscillator together; the surface acoustic wave resonator and the surface acoustic wave detector are arranged in a mutually perpendicular crossing way; the surface of the piezoelectric film at the intersection of the surface acoustic wave resonator and the surface acoustic wave detector forms a blank; and the metal dot matrix is positioned at the blank. The gyro has the advantages of simple and compact structure, low cost, easy and simple operation and the like, can adjust the working frequency of the surface acoustic wave gyro in a certain range, can realize matching of the working frequency of the oscillator and the working frequency of the detector, and effectively improves the sensitivity and accuracy of the surface acoustic wave gyro.

The invention provides a double-frequency broadband E-shaped microstrip antenna, comprising an E-shaped patch 3. A main feeder line 1 is directly connected to an SMA joint 2 of coaxial feeding point of the E-shaped patch 3, the SMA joint passes through the ground and medium and then is directly in contact with the intermediate arm of the E-shaped patch 3, another two arms of the E-shaped patch 3 are symmetrically distributed at the two sides of the feeding point and have a distance of L3 from the edge of the intermediate arm, the E-shaped patch 3 is connected with a T-shaped patch (bent T-shaped patch) 4 by loading to form a main radiating unit of the antenna, a width t is arranged between the E-shaped patch 3 and T-shaped patch (bent T-shaped patch), and a slot with width t2 and depth t1 is respectively arranged at the two sides of the joint between the T-shaped patch (bent T-shaped patch) and the E-shaped patch. The invention has relatively high gain, wide working frequency band, uniform current distribution, light weight and small volume, can effectively improve communication quality, is easily integrated with a circuit, and can be widely used for a portable device and in indoor coverage and wireless local area network.

The present invention relates to a double-component single-piston type hydraulic free-piston engine, which comprises a single-piston hydraulic free-piston engine, an oxidizer storage tank, a fuel agent storage tank, an oxidizer control valve, a fuel agent control valve and an electronic control unit; wherein, both the outlet end of the oxidizer control valve and the outlet end of the fuel agent control valve are communicated with the air inlet of the power cavity of the single-piston hydraulic free-piston engine; the inlet end of the oxidizer control valve is connected with the outlet end of the oxidizer storage tank; the inlet end of the fuel agent control valve is connected with the outlet end of the fuel agent storage tank; and the control end of the oxidizer control valve and the control end of the fuel agent control valve are respectively connected with the corresponding output ends of the electronic control unit. The double-component single-piston type hydraulic free-piston engine, which is characterized by simple structure, reliable operation, wide application range, high energy density, high power density, little moving parts, etc., can operate under various oxygen-deficient or oxygen-free environments, such as plateaus, underwater and outer space, and can realize stroke control and regenerative braking.

The invention discloses a variable-frequency microstrip antenna which comprises a floor, a radiant plate, a connector and at least two short circuit plates, wherein the connector is connected to the radiant plate through a feeding point arranged on the radiant plate; electromagnetic radiation is formed by excitation to the radiant plate through the connector from the downside of the floor; and the conduction state of the short circuit plates is controllable, one ends of the short circuit plates are connected to the radiant plate through connecting points arranged at the edge of the radiant plate and the other ends of the short circuit plates are connected to the floor, and the connecting state of the radiant plate and the floor can be controlled through controlling the conduction state of the short circuit plates. According to the variable-frequency microstrip antenna, the working frequency is changed through changing the conduction state of the short circuit plates; and the variable-frequency microstrip antenna works in a wider frequency band, and the antenna performance is improved.

A dual-frequency reconfigurable micro-strip slot antenna is characterized by comprising a medium substrate, a gap with the length larger than the width is arranged on the medium substrate, the position which is a certain distance away from the left end of the gap is provided with a metal ribbon, one end of the metal ribbon is connected with a floor, the other end of the metal ribbon is connected with an RF-MEMS switch, the other end of the RF-MEMS switch is connected with the floor, and the position which is a certain distance away from the right end of the gap is provided with a micro-strip line. The resonant frequency of the micro-strip slot antenna mainly depends on the length of the gap, the principle that different working frequencies can be obtained by changing the length of the gap is utilized, and therefore the working frequency, the polarization direction and the radiation direction of the antenna are changed in real time by changing the structure and the position of an antenna radiation unit under the condition that the size of the whole antenna is not changed, the integration of the system antenna is achieved, and the size of the system is reduced.

The invention discloses an NFC (near field communication) cellphone circuit system based on a self-adaptive matching circuit. The NFC cellphone circuit system comprises an NFC chip circuit, a filter circuit, a matching circuit and an antenna circuit, which are sequentially connected. The NFC chip circuit is connected with the antenna circuit, the NFC chip circuit comprises an NFC chip, a variable capacitor and a current management control circuit are connected between the matching circuit and the antenna circuit, the variable capacitor is connected with the output end of the matching circuit in parallel, and the current management control circuit is connected with the variable capacitor. Compared with the prior art, the NFC cellphone circuit system can adjust self-operation frequency according to existing POS (point of sales) operation frequency and can be matched with many POS terminals.

The invention relates to an accumulated charge pump, and belongs to the technical field of charge pumps. The boosting aim that an MOSFET passive driving circuit fetches the voltage from a VDS is achieved. After initialization is completed, an S4 and a D1 are cut off due to reversal of biasing of the D1, and a sub-circuit is disconnected. An S1 is closed to buffer a Ui on a C1, meanwhile, an S3 is closed to feed the voltage of an output C3 back to a C2, and an S2 is disconnected in the process. Then the S2 is closed, the S1 and the S3 are simultaneously opened to enable the C2 to be connected with the C1 in series to supply power to the C3, and accumulation of the voltage of the Ui is achieved. After completion of each work cycle, the voltage of each capacitor is that U1=Ui, U2=U3-U1, U3=N*U1+U2, and the N is the switching period number. The accumulated charge pump is applied to the MOSFET passive driving circuit, a low-power boosting type charge pump and the like.

The invention provides a microstrip and substrate integrated waveguide-based dual-frequency band-pass filter and a design method thereof. The filter comprises two coupled gaps positioned in a signal input end and a signal output end respectively, a phase step impedance resonator-based three-order low-pass filter, a 1 / 4 wavelength phase step impedance resonator-based two-order band-pass filter, a section of embedded open circuit stub, three air filled and connected circular cavities, a plurality of metalized via holes distributed in the edges of the circular cavities, a three-layer dielectric substrate, a layer of shared metal ground and a layer of bottom surface metal cover plate. The low-pass filter can realize the frequency response characteristic complementary with the band-pass filterby adjusting lengths of high and low impedances, thereby realizing the microwave band-pass filter based on an ultra-wide stop band; and then by combination with a substrate integrated waveguide circular cavity-based millimeter wave band-pass filter with low-frequency cut-off characteristics, the dual-frequency band-pass filter with ultra-high transmission band ratio is further realized.

The invention discloses a reflective dual-layer liquid crystal phase shifting unit based on a patterned graphene electrode. The reflective dual-layer liquid crystal phase shifting unit comprises an upper medium substrate layer, a middle medium substrate layer and a lower medium substrate layer, a first liquid crystal layer is injected into a gap formed between the upper medium substrate layer andthe middle medium substrate layer, the lower surface of the upper medium substrate layer is provided with a plurality of metal patches which are sequentially connected in series through a connecting line, and a metal microstrip structure is formed; the upper surface of the lower medium substrate layer is fully covered with a metal layer, and a metal grounded electrode is formed; and a second liquid crystal layer is injected into a gap formed between the middle medium substrate layer and the metal grounded layer, and a graphene patch layer which has the same structure as the metal microstrip structure and has the different thickness is arranged on the upper surface of the middle medium substrate layer to serve as a graphene electrode. According to the phase shifting unit, electricity tuningof dielectric constants of two layers of liquid crystal materials can be achieved, and therefore the working bandwidth of the phase shifting unit is increased; and meanwhile, by changing the bias voltage of the graphene electrode, the chemical potential energy of graphene can be changed, and then the working bandwidth of the phase shifting unit is further increased.

The invention relates to a device and a method for realizing electric regulation and control of Fano resonance based on asymmetric split-ring resonators. A variable capacitance diode is embedded in the middle of each of the two split-ring resonators, and meanwhile, feeding wires are added to the upper side and lower side of the two split-ring resonators respectively; the feeding wires are connected with an external power supply and adjust the voltage at the two ends of the variable capacitance diode; and inductors are added between the feeding wires and the split-ring resonators respectively to isolate the influence of the feeding wires on the electromagnetic response of the metamaterial structure. The working state of the variable capacitance diode is adjusted by using the feed voltage, and then the working frequencies of the two split-ring resonators are adjusted, so that dynamic modulation of the Fano resonance transmission spectral line is realized. The two split-ring resonators are different in size, the asymmetric structure is utilized to excite a magnetic four-level mode, and destructive interference occurs between the magnetic four-level mode and a magnetic dipole mode excited by an electric field, so that the transmission spectral line shows a Fano resonance line type.

The invention provides a balanced band-pass filter based on a right-angle triangular paste structure and a design method thereof. The balanced band-pass filter comprises a micro-strip sheet unit, a base plate and a metal ground layer which are arranged from top to bottom in sequence; the micro-strip sheet unit comprises a right-angle triangular micro-strip unit and a half-wavelength resonator; theright-angle triangular micro-strip unit comprises right-angle triangular pastes A1 and A2 which are coupled and cascaded mutually, and also comprises micro-strip feeder lines B1, B2, B3 and B4 whichare embedded into the right-angle sides of each right-angle triangular paste, and the four micro-strip feeder lines are correspondingly connected with a first one-quarter wavelength open-circuit stubline C1, a second one-quarter wavelength open-circuit stub line C2, a third one-quarter wavelength open-circuit stub line C3 and a fourth one-quarter wavelength open-circuit stub line C4; the first right-angle triangular paste A1 and the second right-angle triangular paste A2 are cascaded, and the half-wavelength resonator is loaded between the first right-angle triangular paste A1 and the secondright-angle triangular paste A2.

The present invention relates to a double-component single-piston type hydraulic free-piston engine, which comprises a single-piston hydraulic free-piston engine, an oxidizer storage tank, a fuel agent storage tank, an oxidizer control valve, a fuel agent control valve and an electronic control unit; wherein, both the outlet end of the oxidizer control valve and the outlet end of the fuel agent control valve are communicated with the air inlet of the power cavity of the single-piston hydraulic free-piston engine; the inlet end of the oxidizer control valve is connected with the outlet end of the oxidizer storage tank; the inlet end of the fuel agent control valve is connected with the outlet end of the fuel agent storage tank; and the control end of the oxidizer control valve and the control end of the fuel agent control valve are respectively connected with the corresponding output ends of the electronic control unit. The double-component single-piston type hydraulic free-piston engine, which is characterized by simple structure, reliable operation, wide application range, high energy density, high power density, little moving parts, etc., can operate under various oxygen-deficient or oxygen-free environments, such as plateaus, underwater and outer space, and can realize stroke control and regenerative braking.

The invention discloses a valley-switching digital control circuit of a switch power source, and belongs to the technical field of switch power source circuit design. The valley-switching digital control circuit comprises a voltage feedback detection module, a current feedback detection module, an arithmetic unit, a valley-switching digital control module, a and gate device and a PWM generating module, wherein the voltage feedback detection module is used for collecting switch power source voltage feedback signals, the current feedback detection module is used for collecting drive switch tube currents, the arithmetic unit is used for obtaining drive switch tube breakover signals according to voltage feedback detection module output signals and current feedback detection module output signals, the valley-switching digital control module is used for obtaining valley-switching signals according to the voltage feedback detection module output signals, the and gate device is used for conducting and operation on the drive switch tube breakover signals and the valley-switching signals, and the PWM generating module is used for generating actual duty ratio signals according to the operation result of the and gate device. By means of the valley-switching digital control circuit, the switch loss is effectively reduced while accurate valley switching is achieved, the valley-switching mode is switched into the real-time breakover mode when the resonant period is abnormal, and the valley-switching digital control circuit is suitable for discontinuous-mode switch power source chips in the PWM mode and PFM mode.

The invention discloses a coplanar waveguide feed capacitor-loaded stepped impedance type half-slot antenna, and relates to a slot antenna. The antenna comprises a dielectric substrate (1), and a metal ground (2) and a radiation slot slit (3) on the dielectric substrate (1), and a coplanar waveguide feeder line (4); the radiation slot slit (3) is formed in the metal ground (2); one end of the radiation slot slit (3) is in short circuit while the other end (6) of the radiation slot slit is in open circuit; a low resistance slot slit (8), which is formed by multiple capacitors (7) that are bridged on the edge of the radiation slot slit (3) in parallel, is formed in the part, close to the open circuit end, of the radiation slot slit (3); a high resistance slot slit (9) is formed in the rest part of the radiation slot slit (3); the outer conductor (5) of the coplanar waveguide feeder line (4) is connected with the metal ground (2); and the inner conductor (12) at the tail end crosses over the high resistance slot slit (9), and is connected with the metal ground (2) on the edge (11) of the high resistance slot slit (9). The antenna is in multi-band operation, so that the antenna dimensions, and the conditions of crossed polarization and shielding can be reduced, and isolation among ports can be improved.

The invention belongs to missile simulation technology, and relates to a Ku-Ka band frequency conversion device for semi-physical simulation of a missile guidance system, including: a public reference source [1]: providing a frequency reference for the entire frequency conversion device; a down-conversion component [2]: used for The Ka-band reference signal from the radar seeker is down-converted to the Ku-band; the up-conversion component [3]: is used to up-convert the Ku-band signal processed by the target echo simulator to the Ka-band; a missile guidance of the present invention The special Ku-Ka band frequency conversion device for system hardware-in-the-loop simulation is attached to the target echo signal simulator, and the target echo signal simulator can be changed without affecting the function and performance of the Ku-band target echo signal simulator. The operating frequency enables it to work in the Ka band. The operation method of the invention is simple, has high reliability, and can make full use of equipment resources.

The invention relates to an HID (High Intensity Discharge) electronic ballast, which comprises an EMI (Electro-Magnetic Interference) filtering and rectifying circuit, an active power factor correcting circuit, a high-frequency half-bridge inverter circuit, a lighting circuit and high-frequency half-bridge inversion driving circuit, and is characterized by further comprising a constant-power control circuit, wherein the input end of the constant-power control circuit is connected with the output end of the active power factor correcting circuit; the output end of the constant-power control circuit is connected with the high-frequency half-bridge inversion driving circuit; and the constant-power control circuit is used for acquiring current at the output end of the active power factor correcting circuit and outputting different control signals to the high-frequency half-bridge inversion driving circuit to adjust the working frequency of a control chip in the high-frequency half-bridge inversion driving circuit and realize correction and / or adjustment on the power of an HID bulb. Compared with the prior art, the HID electronic ballast has the advantages that: the constant-power control circuit is arranged, so that the HID electronic ballast provided by the invention has the characteristics of high reliability and capability of keeping stable work of the HID bulb.

The invention discloses a modem of a cable television system. The modem comprises a power conversion unit, an output control and connection stealing detection unit, an uplink control unit, an uplink transmitting unit, a mixer, a downlink receiving unit, a downlink control unit and a data connection unit. The power conversion unit converts an input power supply into a power supply required by other units. The output control and connection stealing detection unit is connected with a household television use terminal, can produce an uplink message which at least contains a connection stealing state, and transmits the uplink message to a computer through the uplink control unit, the uplink transmitting unit, the mixer and the data connection unit in an ASK mode. The data connection unit can transmit a downlink message of the computer to the output control and connection stealing detection unit through the mixer, the downlink receiving unit and the downlink control unit in a FSK mode. The playing of a cable television signal of the household television use terminal can be controlled.

The invention relates to a radial vibration annular piezoelectric ceramic composite transformer which comprises a piezoelectric ceramic inner ring and a piezoelectric ceramic outer ring. A metal conducting ring is coaxially arranged between the piezoelectric ceramic inner ring and the piezoelectric ceramic outer ring, the piezoelectric ceramic inner ring, the piezoelectric ceramic outer ring and the upper end face and the lower end face of the metal conducting ring are placed in the same plane, and the height H of the piezoelectric ceramic inner ring, the height H of the piezoelectric ceramic outer ring and the height H of the metal conducting ring are smaller than or equal to D / 6 of the outer diameter of the piezoelectric ceramic outer ring. According to the novel radial vibration annular piezoelectric ceramic composite transformer, the metal circular ring is additionally arranged between an input piezoelectric ceramic device and an output piezoelectric ceramic device, and the effects of improving the radiating of the transformer, enlarging the power capacity of the transformer and improving the electromechanical properties of the transformer can be achieved. Meanwhile, the radial polarized piezoelectric ceramic circular rings are utilized, and the polarization and the excitation orientation of the piezoelectric ceramic circular rings are consistent. The radial vibration annular piezoelectric ceramic composite transformer belongs to a longitudinal effect vibration mode which is similar to a Kt vibration mode, and the electromechanical excitation and conversion efficiency of the piezoelectric ceramic transformer can be improved.

The invention discloses a novel optically controlled microwave oscillator, including a bias resistor, first coupled microstrip circuit, second coupled microstrip circuit, output microstrip circuit, microwave field effect transistor and resonator, one end of the first coupled microstrip circuit is connected to the grid of the microwave field effect transistor, the other end of the first coupled microstrip circuit is connected to one end of the bias resistor, and the other end of the bias resistor is grounded. The drain of the microwave field effect transistor is divided into two channels, one is connected with the second coupling microstrip circuit, the other is connected with one end of the output microstrip circuit, the other end of the output microstrip circuit is used as the output end,the source of the microwave field effect transistor is grounded, and the resonator is coupled with the first coupling microstrip circuit and the second coupling microstrip circuit at the same time. The resonator is a semiconductor composite dielectric resonator, which can produce a plasma layer when the light is irradiated, so that the resonant frequency of the resonator is changed, thereby changing the working frequency of the whole microwave oscillator and realizing the control of the microwave oscillator. The structure is simple and the sensitivity is high.

The invention discloses an automatic frequency calibration system of an electrically tuned duplexer, and relates to the field of microwave communication. The system comprises a frequency calibration unit, a first switch, a second switch, a generating tuned filter, a receiving tuned filter, a circulator, a radio frequency self-circulator, a low-noise amplifier and the like, wherein the frequency calibration unit is used for carrying out variable frequency amplifying and filtering on received signals, sequentially sampling, comparing, judging and counting filtered signals, and outputting a specified generating frequency to the generating tuned filter or outputting a specified receiving frequency to the receiving tuned filter after a preset threshold is reached. Through cooperation of the frequency calibration unit and the switches, the electrically tuned duplexer achieves automatic frequency calibration and has the characteristics of high intelligent and automatic degrees; the work frequency can be automatically changed and calibrated within a wide frequency range through electromechanical combination and software-hardware combination; the tuning speed is high; the accuracy and the stability of the work frequency of the duplexer are kept in high and low temperature environments; and the frequency calibration system is the automatic frequency calibration system of the electrically tuned duplexer with high universality and high integration.

The invention discloses an on-chip multi-band terahertz three-dimensional antenna. The antenna is mainly composed of ten radiation patches and ten NMOS transistor switches. The characteristics of multi-layer metal of a TSMC 40nm CMOS process are utilized. A planar antenna structure is changed into a three-dimensional structure. Each layer of metal of M1 to M10 is designed into a rectangular radiation patch with a simple structure. An I-shaped groove is formed in the middle. A section of microstrip transmission line is led out to be connected with a source electrode of an NMOS tube. A microstrip feeder line is connected with a drain electrode of the NMOS tube, and a grid electrode of the NMOS tube is connected with bias voltage. By adjusting the grid bias voltage of the NMOS tube and conducting the NMOS tube, a switch is closed, and a layer of radiation patch is added to the antenna, so that the shape of the antenna is changed, and a new working frequency is obtained. When all the switches are closed, the antenna is of a three-dimensional structure formed by connecting ten layers of radiation patches, and various different working frequencies can be achieved. Besides, the antenna and a terahertz circuit are integrated on the same chip, and a terahertz detector is designed, so that a multi-band detection function can be realized.

The invention discloses a dual-frequency antenna which comprises a slot vibrator antenna and a microstrip antenna, wherein the slot vibrator antenna and the microstrip antenna are arranged in combination with each other. The slot vibrator antenna is in a cylindrical symmetrical structure which is composed of a back cavity casing body with an air back cavity and is centered on a support rod. An annular radiation slot is arranged around the center point at the upper part of the back cavity casing body. The microstrip antenna is in a structure with a support rod. A mounting plate and a radiationactinal surface are arranged at the upper part of the support rod. A coaxial feeding medium is arranged and filled in the hollow cavity of the support rod. Through the study and design of the structure and arrangement manner of the key components of the dual-frequency antenna, such as the radiation slot, the radiation actinal surface and the feeding, the structure of the dual-frequency antenna with the combined microstrip antenna and slot vibrator antenna is symmetrical. The dual-frequency antenna has the advantages of symmetrical directional diagram, non-distortion beam and high isolation.

The invention relates to a high-voltage plasma power supply comprising a three-phase half-control rectification circuit, a time-delay starting circuit, a filtering energy storage circuit, a full-bridge circuit, an LC series resonance circuit, a low-voltage rectification circuit, a power regulation circuit, a feedback control circuit, a frequency conversion circuit, an IGBT full-bridge driving circuit, and an alarm circuit, the three-phase half-control rectification circuit is connected with a high-voltage transformer via the full-bridge circuit and the LC series resonance circuit, the power regulation circuit and the feedback control circuit are connected with the feedback control circuit, and the feedback control circuit is connected with the full-bridge driving circuit via the frequency conversion circuit.

The invention discloses a direct contact type hygrostat based on compressor frequency control and a method thereof. The hygrostat comprises a cabinet, a fan, a compressor, a condenser, a water tank, a throttle valve, an electromagnetic reversing valve, a frequency converter and an evaporator. The compressor, the condenser, the electromagnetic reversing valve, the throttle valve and the evaporator are connected sequentially; the evaporator is arranged in the water tank, the air inlet of the fan is communicated with outside through a fresh air pipe, the air outlet of the fan is connected to a spraying pipe, and the spraying pipe is inserted into the bottom of the water tank from the right of the water tank; the top of the water tank is provided with a guide plate, and the air outlet of the top is provided with an air blowing pipe. According to the hygrostat, the water temperature is adjusted through the refrigerating capacity of the compressor, and the air dehumidification is changed by controlling the water temperature; the system further adopts the electromagnetic reversing valve, when air humidification is required, the system operates in a manner of a heat pump, the water temperature rises, and humidification is performed conveniently; the hygrostat is compact in structure and is specially adaptive to constant humid environment of a large showcase or antique storeroom.

The half-slot antenna with coaxial feeding metal via hole step impedance relates to a slot antenna, which includes a dielectric substrate (1), a metal ground (2) on the dielectric substrate (1), a radiation slot (3), and a coaxial feeder (4); there is a radiation slot (3) on the metal ground (2); one end of the radiation slot (3) is short-circuited, and the other end (6) is open; there are two rows of metal wires near the open end of the radiation slot (3). The low-resistance slot (8) is formed by the via hole (7) array; the rest of the radiation slot (3) is a high-resistance slot (9), and the outer conductor (5) of the coaxial feeder (4) is connected to the metal ground (2 ), the inner conductor (12) at the end of the coaxial feeder (4) straddles the high-resistance slot (9) at its edge (11), and connects with the metal ground (2). The antenna is multi-band operation which reduces antenna size, cross-polarization, shadowing and improves isolation.

The invention provides a bulk acoustic wave resonator, a manufacturing method thereof, a filter and a duplexer. The bulk acoustic wave resonator comprises a substrate, an acoustic reflection unit on the substrate, a piezoelectric stack structure on the acoustic reflection unit, and a welding pad on the piezoelectric stack structure, wherein the bulk acoustic wave resonator further comprises a three-dimensional mass load structure on the piezoelectric stack structure and / or in the piezoelectric stack structure. According to the bulk acoustic wave resonator, the manufacturing method thereof, thefilter and the duplexer, the process is simple, the cost is low, and performance optimization is facilitated.

The invention relates to a horizontally polarized omnidirectional antenna based on artificial local area surface plasmon. The antenna mainly comprises a dielectric plate, an artificial surface plasmonwaveguide structure and a coplanar waveguide matching structure which are located on the back surface of the dielectric plate, and an artificial local surface plasmon resonance unit structure on thefront surface of the dielectric plate. According to the invention, omnidirectional radiation horizontally polarized electromagnetic waves can be obtained. The antenna is manufactured by adopting a common PCB process, is convenient to process, has the characteristics of miniaturization and low profile, improves the integration level of a system, and has a good application prospect.