85results about How to "Lower cutoff frequency" patented technology

Methods and devices for fabricating AlGaN/GaN normally-off high electron mobility transistors (HEMTs). A fluorine-based (electronegative ions-based) plasma treatment or low-energy ion implantation is used to modify the drain-side surface field distribution without the use of a field plate electrode. The off-state breakdown voltage can be improved and current collapse can be completely suppressed in LDD-HEMTs with no significant degradation in gains and cutoff frequencies.

An electroacoustic transducer includes a condenser microphone, which includes a package having a cavity and a through-hole, a plate whose thickness is thinner than the length of the through-hole and which has a sound hole overlapping with the through-hole in plan view, and an electroacoustic transducer die, which is stored in the cavity of the package. The electroacoustic transducer die includes a fixed electrode and a diaphragm electrode, which are positioned opposite to each other and which are supported by and enclosed inside of a support. The sound hole of the plate is reduced in dimensions realizing a small sectional area and a small depth, thus realizing a high resonance frequency higher than the audio frequency range.

Apparatus and methods for acoustically isolating logging tool receiver and transmitter sections. One or more modular isolators is arranged between the receiver and transmitter sections. The modular isolators comprise a high tensile strength while also providing for a high wave attenuation level. The modular isolators are mechanical mass-spring systems capable of absorbing acoustic waves propagating along the logging tool. The mass is a swinging sleeve, and the spring includes a Belleville spring stack. The use of the strong modular isolators provides acoustic isolation between the transmitters and receivers for the complete sonic frequency band at multiple modes.

The invention discloses a plate or bridge structure of a local resonance acoustic black hole (ABH). The local resonance acoustic black hole structure comprises an acoustic black hole region (a region which is gradually thinned), a local vibrator (such as a mass spring unit) and an acoustic black hole extension part. According to the local resonance acoustic black hole structure disclosed by the invention, the local vibrator is constituted by units having the properties of a spring vibrator, so that an effective action frequency range of an acoustic black hole effect is reduced, and subsequently, a vibration control effect of the acoustic black hole structure is effectively improved. The local resonance acoustic black hole structure disclosed by the invention has a broad application prospect in vibration absorption and noise reduction of structures.

The invention discloses a sidehole-free angle-selection laser filter. The filter comprises a first volume Bragg grating for diffracting incident light for the first time and a second volume Bragg grating for diffracting diffracted light from the first volume Bragg grating for the second time, wherein vectors of the first and second volume Bragg gratings are parallel, and a large diffraction level of the first volume Bragg grating corresponds to the diffraction zero value of the second volume Bragg grating. The sidehole-free angle-selection laser filter of the invention can effectively overcome the sidehole defect of a common angle-selecting laser filter, and can realize space filtering in a higher quality; the structure is compact; and low-pass filtering can be excellently carried on different spectral components, and bearable laser power is higher.

The invention discloses an ultra-wide-band horizontally-polarized omnidirectional connection type Vivaldi circular array antenna, and mainly solves the problems of wide frequency band, omnidirectional horizontal polarization and miniaturization of an antenna cannot be satisfied in the prior art. The ultra-wide-band horizontally-polarized omnidirectional connection type Vivaldi circular array antenna comprises a radiation unit (1), a feeding network (2) and a dielectric plate (3), wherein the radiation unit (1) is a 16-element connecting type Vivaldi antenna array which is formed by a Vivaldi unit around a center in a rotating manner; the feeding network (2) adopts a one-into-sixteen broadband Wilkinson power divider and a coupling microstrip feeder line; electromagnetic energy is coupled to the radiation unit through the coupling microstrip feeder line; the dielectric plate (3) adopts a Kangtaini (a Chinese brand name)dielectric plate with a dielectric constant of 2.55; the radiation unit and the feeding network are printed on the upper and lower surfaces of the dielectric plate; and the centers of the radiation unit and the feeding network coincide with that of the dielectric plate. The circular array antenna has the characteristics of ultra wide band, omnidirectional horizontal polarization and miniaturization, and can be used in a full-coverage ultra-wide-band wireless communication system in the peripheral regions.

A device for detecting a failure of a filter used to clean a gas stream, in particular an exhaust gas stream, of soot particulates, including a chamber which is insertable into the gas stream to be cleaned in addition to the filter and which is at least partially closed by a filter body and has at least one opening through which gas entering the chamber through the filter body can exit the chamber, at least one gas sensor for determining the concentration of at least one component of the gas to be cleaned being arranged in the chamber, and at least one second gas sensor for determining the concentration of the at least one component of the gas to be cleaned being arranged outside the chamber.

The invention discloses an ultra-wideband double-ridge horn antenna for a 1-40GHz frequency band, and belongs to the technical field of antennas. The problems are solved that an existing double-ridgehorn antenna is poor in low-frequency-band matching performance, high-frequency-band directional diagram main lobes are split, and gain is reduced. The antenna comprises a ridged horn and a feed structure, the ridged horn comprises a shell, an upper ridge and a lower ridge, the shell is a rectangular cone structure, metal grids are arranged on the left side wall and the right side wall of the shell, the upper ridge and the lower ridge are fixedly arranged on the inner sides of the upper side wall and the lower side wall of the shell respectively, and the ridge line of the upper ridge and the ridge line of the lower ridge are curves; the feed structure comprises a coaxial line, a metal floor and a waveguide section, the metal floor is vertically arranged, the coaxial line is horizontally arranged, and the coaxial line is connected with the ridged horn through the metal floor and the waveguide section.

The invention is applied to the field of printed circuit boards, and particularly relates to a broadband electromagnetic band gap structure applied to a power plane of a printed circuit board. The broadband electromagnetic band gap structure at least comprises a nonconductive substrate, metal boards are covered on and under the nonconductive substrate and corroded to be electromagnetic band gap units distributed at intervals, a gap is etched on a metal paster in a unit cell of the electromagnetic band gap structure, and a groove is formed around the metal paster in the unit cell of the electromagnetic band gap structure. The broadband electromagnetic band gap structure has wider relative bandwidth and lower cutoff frequency, basically covers noise frequency band of simultaneous switch noise and can omnidirectionally eliminate simultaneous switch noise positioned between the power plane and a ground plane. Due to adoption of an existing conventional printed circuit board manufacturing process, the broadband electromagnetic band gap structure is easy to realize and high in benefit.

The invention discloses a frequency scanning CTS flat panel array antenna, includes a radiation layer and a broadband line source layer arranged in order from top to bottom, the radiation layer includes a first radiation element and a second radiation element, a first radiating element is located above the second radiating element, the first radiation unit includes a first metal plate and 17 continuous transverse branches disposed on the first metal plate, the first metal plate is a rectangular plate, 17 consecutive transverse branch are uniformly spaced from left to right on that first metalplate. The second radiating unit comprises a second metal plate on which a non-uniform slow wave structure, a sixth rectangular waveguide cavity and a seventh rectangular waveguide cavity are sequentially arranged from left to right, and a broadband line source layer comprises a third metal plate, a single ridge waveguide feeding network and a single ridge waveguide. The second radiating unit comprises a second metal plate, wherein the second metal plate is provided with a non-uniform slow wave structure, a sixth rectangular waveguide cavity and a seventh rectangular waveguide cavity from leftto right Rectangular waveguide converter and quasi-TEM mode line source generator. The invention has the advantages of small size, high gain and high efficiency.

The invention can be applicable to a CMOS image sensor. In the CMOS image sensor, every pixel circuit of an active pixel sensor array includes a photoelectric transition element which is used for transiting input lights into electricity and a switching transistor which is used for controlling the reduction voltage supply to the photoelectric transition element. The reduction voltage is used for resetting the photoelectric transition element to the predetermined voltage. The CMOS image sensor includes a control circuit which is used for distributing control signals that are applied on the control electrode of the switching transistor. In the first part of the reduction period of the photoelectric transition element, the control circuit outputs first voltage which is higher than the power voltage of the CMOS image sensor to change the ON resistance of the switching transistor to be as small as possible. And in the back part of the reduction period of the photoelectric transition element, the control circuit outputs second voltage which is lower than the power voltage of the CMOS image sensor.

The invention discloses an electromagnetic band gap structure for achieving ultra-wideband suppression of synchronous switching noise. The electromagnetic band gap structure is characterized in that arectangular notch is etched on each side of a power plane, and a microstrip line is led out from the middle point of the bottom of the notch; the microstrip line surrounds the power plane to the tailend of the next side in a counterclockwise direction, and the part of the microstrip line positioned at the next side surrounds the part of the microstrip line positioned at the side, which is led out from the rectangular notch at the side; the microstrip line is connected with the microstrip line of the adjacent structural unit to form an S shape; the central area of the power plane is hollow, and a square plane plate is inlaid in the central area; a rectangular notch is etched in the center of each of four sides of the square plane plate, and a microstrip line is led out from the middle point of the bottom of the rectangular notch and connected with the power plane. The electromagnetic band gap structure better reduces the lower cut-off frequency of noise suppression and effectively enlarges the bandwidth range of noise suppression, thereby achieving the ultra-wideband suppression of the synchronous switching noise between the power plane and a ground plane.

The invention discloses a novel electromagnetic band gap structure for suppressing synchronous switch noise. The electromagnetic band gap structure is etched on a power plane; all unit structures areconnected through S-shaped micro-strip lines; and an L-shaped micro-strip line is arranged in each unit structure. According to an S-shaped bridge structure, the inductance of a bridge structure of the electromagnetic band gap structure is increased, so that the lower cut-off frequency of noise suppression is reduced; and the S-shaped bridge structure can suppress the SSN in a stop band range to ensure that the noise cannot be transmitted to outside, so that the bandwidth range of the noise suppression is effectively expanded, and the ultra-wideband suppression of the SSN between the power plane and a ground plane is achieved. When the suppression depth is -40dB, the suppression bandwidth ranges from 0.26GHz to 25GHz.

The invention discloses an active scanning orthogonal vector digital phase-locked amplifier. The active scanning orthogonal vector digital phase-locked amplifier comprises a signal conditioning module, a signal acquisition module, a data processing and modulating signal/scanning signal module, a communication module and a liquid crystal display module. The signal conditioning module is used for performing preprocessing such as pre-amplifying, notching and anti-aliasing filtering, and the preprocessed signal is cached in a caching and input signal processing module FPGA chip after A/D high-speed data acquisition, and then stored in an external memory. Two synchronous frequency-doubling reference signals are generated inside the FPGA and then put into an orthogonal vector digital demodulation (DILA) processing unit with a signal to be tested, and a harmonic signal is output after DILA operation. The harmonic signal data are communicated with an upper computer by virtue of network transmission or a serial manner, or output by virtue of a USB. The modulating and scanning signal module inside the FPGA chip generates modulating and scanning signals.

The invention discloses an ultra wide-band filter response power divider, and mainly solves the problem that the band width of a power divider is too narrow in the prior art. The ultra wide-band filter response power divider comprises a micro-strip dielectric substrate (1), an input port (2), two output ports (7, 8), an upper wide-band filter (3) and a lower wide-band filter (4), wherein the upper wide-band filter (3) is formed by cascading a high-pass filtering unit (31), a step impedance transmission line (32) and a low-pass filtering unit (33). The high-pass filtering unit consists of a main transmission line and a pair of short circuit branch knots, the low-pass filtering unit is formed by cascading three low impedance transmission lines and four pairs of high impedance branch knots alternately, and the high-pass filtering unit and the low-pass filtering unit are connected through the step impedance transmission line in a matching manner; the lower wide-band filter (4) and the upper wide-band filter (3) are the same in structures and are symmetrically arranged, and an isolating resistor (6) is arranged between the lower wide-band filter (4) and the upper wide-band filter (3). The ultra wide-band filter response power divider can realize band-pass filtering response of 3GHz to 16GHz, and can be used for the radio frequency front ends of wireless communication systems.

The invention discloses a U-shaped electromagnetic band gap circuit board with a low-frequency simultaneous switching noise inhibiting function, which mainly solves the problem that the existing electromagnetic band gap circuit board has limited capacity on inhibiting low-frequency simultaneous switching noise with the frequency lower than 1GHz. The electromagnetic band gap circuit board consistsof an electromagnetic band gap layer (1), a stratum (2) and a dielectric layer (3), wherein the electromagnetic band gap layer (1) is formed by connecting n electromagnetic band gap units (4) and thenumber n is determined according to actual engineering needs. The middle position of each edge of the electromagnetic band gap units (4) is provided with a rectangular slot (5), an L-shaped connecting line (6) is led out from the middle position of the rectangular groove from inside to outside, and every two electromagnetic band gap units (4) are symmetrically connected through one L-shaped connecting line to form a U-shaped bridging line, so the electromagnetic band gap units (4) are connected to form the electromagnetic band gap layer (1). The U-shaped electromagnetic band gap circuit boarddisclosed by the invention has stronger capacity in inhibiting the low frequency range simultaneous switching noise, can reduce the interference of the noise on signal transmission and the false operation of electronic devices, and can be used in high frequency electronic circuits of microwaves, antennae and communication.

The invention is applied to the field of printed circuit boards, and particularly relates to an ultra-wide band electromagnetic band-gap structure applied to power planes of printed circuit boards. The elementary cell of the ultra-wide band electromagnetic band-gap structure consists of spinning branches and slots of square metal patches. The spinning branches of the elementary cell of the electromagnetic band-gap structure surround the square metal patches. The slots are etched on the metal patches of the elementary cell of the electromagnetic band-gap structure. Four sides of the metal patches of the elementary cell of the electromagnetic band-gap structure are grooved. The electromagnetic band-gap structure has wider bandwidth and lower cut-off frequency, basically covers noise band of noises of a synchronous switch, and can eliminate noises of the synchronous switch between the power planes and the ground plane omnidirectionally. The ultra-wide band electromagnetic band-gap structure produced by the conventional printed circuit board manufacturing process is easy to realize and has high benefit.

The invention discloses a broadband ridge waveguide power synthesizer based on a gradient ridge and a power synthesizer device. The synthesizer has a compact structure, large bandwidth, low insertionloss and high bearing power and can realize higher power synthesis output. The broadband waveguide power synthesizer comprises a ridge waveguide which is composed of an upper cavity, a ridge cavity and a lower cavity, a first port which is arranged at one end of the ridge waveguide, a second port which is arranged at the other end of the ridge waveguide, a third port which is arranged at the frontend of the ridge waveguide and the gradient ridge, an penetrating ridge and a chamfered ridge which are arranged in the ridge cavity.

The invention discloses a vertical parasitic type plug-and-play (PNP) audion in a germanium silicon heterojunction bipolar transistor (HBT) technology. A window defining germanium before growth in a trapezoid shape is adopted and germanium silicon layers in an emitter region can be in a polycrystalline structure, and therefore dosage concentration in the emitter region can be improved, emitting efficiency and amplification coefficient of a device is improved, and cut-off frequency of the device is increased. Due to the fact that the advanced deep hole contact technology and the P-type buried layer technology are adopted, area of an active region can be greatly saved, parasitic effect of the device is improved, collector resistance of the device is reduced, and performance of the device is improved. The invention further discloses a manufacture method of the vertical parasitic type PNP audion in the germanium silicon HBT technology. The manufacture method can be integrated with the technology of the PNP audion in the germanium silicon HBT technology and reduce production cost.

The invention discloses an optical proximity correction figure for enhancing the figure fidelity of a Si/Ge emitter window. The figure consists of two end parts and a middle part, wherein the two end parts have the same size and are split into two structures with small holes at a certain interval respectively; the middle part is a totally-rectangular structure or split into two rectangles at a certain interval; and a certain distance exists between the two end parts and the middle part. The figure fidelity of the emitter window in a Si/Ge apparatus can be enhanced, so that the variations of a cutoff frequency and an amplification factor of the Si/Ge apparatus caused by the shape variation of the emitter window are reduced.

The invention discloses an SIW-based single-ridge ultra-wideband H-plane horn antenna, and aims to solve the technical problem that in the prior art, a substrate integrated waveguide ridged horn antenna is relatively complex in structure. The antenna comprises a dielectric substrate, an SIW structure, an H-plane horn antenna, a ridge structure and a feed coaxial line, the SIW structure and the H-plane horn antenna are arranged on the two sides of the central axis of the dielectric substrate, the ridge structure is arranged on the central axis of the dielectric substrate, and the feed coaxial line is arranged on the side, close to the SIW structure, of the ridge structure; and the SIW structure and the H-plane horn antenna comprise metalized through holes symmetrically distributed relative to the central axis of the dielectric substrate and metal layers on the upper surface and the lower surface of the dielectric substrate, and the ridge structure comprises a plurality of connected metal blocks. According to the invention, the equivalent characteristic impedance of the SIW can be effectively reduced, the cut-off frequency of a main mode is reduced, the working bandwidth of the horn antenna is increased, and the antenna structure is simplified.