293results about How to "Large tuning range" patented technology

A metal oxide semiconductor (MOS) varactor includes a first terminal and a second terminal, and the MOS varactor comprises a substrate; a deep well, formed on the substrate; and a first MOS device, formed on the deep well; wherein a gate of the first MOS device is coupled to the first terminal, and a source and a drain of the first MOS device are coupled to the second terminal.

A sub-wavelength grating structure that has a very broad reflection spectrum and very high reflectivity comprising segments made of high refractive index material disposed on a layer of low refractive index material and a low refractive index material disposed above and between the segments. The index differential between the high and low index materials determines the bandwidth and modulation depth. The larger difference in refractive indices gives rise to wider reflection bands. The reflection is sensitive to parameters such as the grating period, the grating thickness, the duty cycle of the grating, the refractive index and the thickness of the low index layer underneath the grating. The design is scalable for different wavelengths, and facilitates monolithic integration of optoelectronic devices at a wide range of wavelengths from visible to far infrared. The sub-wavelength grating reflectors may be used in a variety of settings such as tunable etalon filters and as a replacement for conventional distributed Bragg reflectors.

The invention discloses a miniature F-P (Fabry-Perot) cavity tunable filter and a method for manufacturing the same. The miniature F-P cavity tunable filter comprises a substrate. An antireflection film is attached to one surface of the substrate, a first bragg reflector is attached to the other surface of the substrate, and a first electrode and a second electrode are attached onto the first bragg reflector; four metal piers are attached onto the first electrode, and a bridge surface is attached onto the four metal piers; the bridge surface comprises four cantilever beams and a movable diaphragm, each cantilever beam is L-shaped, one end of each cantilever beam is perpendicularly fixedly connected with the corresponding metal pier, and the other end of each cantilever beam is connected with the movable diaphragm; the movable diaphragm is square, and a second bragg reflector is inlaid in the center of the movable diaphragm; the first bragg reflector and the second bragg reflector form a resonant cavity of an F-P cavity; after the miniature F-P cavity tunable filter is powered on, the four cantilever beams elastically deform and can drive the movable diaphragm and the second bragg reflector to move in the direction perpendicular to the first bragg reflector, so that the length of the resonant cavity is changed, and a tunable function of the filter is realized. The miniature F-P cavity tunable filter and the method have the advantage that the filter is wide in tunable range and high in response speed.

An on-chip response adjuster is based on an on-purpose generated and dominant transfer pole or zero of a signal response so as to provide a process-stable phase behavior of the circuitry. The signal response is defined directly by a passive frequency variant component (Lfold) and by transistor operation point, e.g. biasing, of a transistor configuration (Qcas,Qaux). As a result, electrically controlled signal response adjusters can be provided with fully integrated, single-chip integrated or system-on-chip (SoC) techniques.

The invention discloses a terahertz isolator device of a magnetic surface plasma waveguide and a control method thereof. The asymmetric and periodic surface plasma waveguide is formed by a metal wall and a semiconductor indium antimonide pillar array. By exerting an external magnetic field under low temperature, the indium antimonide shows the revolving electrical property, and the structure can generate a magnetic surface plasma mode, so that the function of unidirectional isolation transmission of the terahertz wave can be achieved. The unidirectional transmission working frequency range is higher than 1THz, the bandwidth is larger than 80 GHz, the isolation reaches 90dB, the insertion loss is lower than 0.25dB, and tuning on the working frequency range can be performed by controlling the external magnetic field strength. Under the temperature of 186K, the frequency of the external magnetic field can be adjusted to 0.7T from 0.1T, and the central working frequency of a unidirectional transmission frequency band of the device can be tuned to 1THz from 1.42THz. The terahertz isolator is low in loss, high in isolation, tunable in broadband and capable of reducing echo and scattered noises in a terahertz application system and improving transmission quality of the terahertz beam.

The invention is directed to a tunable diffraction grating (1) with optically active elements (5) arranged at a distance (A) next to each other. The optically active elements (5) are displaceable relative to each other in a lateral direction (x, y) and mechanically interconnected to a layer (4), which is made out of a deformable material. A deformation of the layer (4) in a direction (z) in general perpendicular to the lateral direction (x, y) causes a change in the relative distance (A) of the optically active elements (5).

The invention belongs to the technical field of radio frequency wireless receiver integrated circuits, and relates to a quadrature voltage controlled oscillator in a wireless receiver integrated circuit. In the quadrature voltage controlled oscillator, the phase noise performance of the quadrature voltage controlled oscillator circuit is improved and the output phase mismatch is reduced by improving a coupling mode of the conventional quadrature voltage controlled oscillator and introducing a phase shift network at the source end of a coupling tube. By using a linearly changed an accumulation-type metal-oxide semiconductor (MOS) variable capacitor array, the linearity of a tuning curve of a quadrature voltage controlled oscillator (QVCO) is greatly improved so that the tuning range of a control voltage is increased. Because a bias current of the QVCO is variable, a relatively constant output oscillating voltage amplitude can be maintained; therefore, a low phase noise can be obtained by the QVCO in a broad output frequency range.

The invention discloses a narrow-linewidth adjustable external cavity laser based on a silicon substrate and relates to the field of integrated optics in optical communication. The narrow-linewidth adjustable external cavity laser based on the silicon substrate is characterized in that a light source is connected with a first MMI (man-machine interface) by virtue of a silicone substrate optical coupler; the first MMI is respectively connected with input terminals of two arms of an asymmetric Mach-Zehnder interferometer, and output terminals of the two arms are connected with a third MMI by virtue of a second MMI; the third MMI is respectively connected with input terminals of an add channel and a drop channel of a silicon substrate micro-ring filter; and output terminals of the add channel and the drop channel are respectively connected with a first grating coupler and a second grating coupler. Free spectral range of the silicon substrate micro-ring filter is 5-50nm, and the free spectral range of the asymmetric Mach-Zehnder interferometer is 1-4 times that of the silicon substrate micro-ring filter. The narrow-linewidth adjustable external cavity laser based on the silicon substrate has the advantages that tuning range of wide wavelength can be widened, so that laser light can obtain narrow linewidth; and the narrow-linewidth adjustable external cavity laser based on the silicon substrate is a miniaturized cavity laser and is low in manufacturing cost, easy to integrate and low in technological tolerance, thereby being applicable to popularization.

The present invention discloses a tunable substrate integrated waveguide circular resonant cavity filter. A symmetric circular SIW resonant cavity structure is used as a basic unit, and the middle dielectric substrate of the circular SIW resonant cavity structure is provided with an air slot in the diameter direction of the middle dielectric substrate. The air slot is internally provided with a metal column capable of moving along the diameter direction of the middle dielectric substrate, and a turning unit is formed by the air slot and the metal column. The main mold resonance frequency of the circular SIW resonant cavity structure is adjusted through adjusting the circle center distance between the metal column and the middle dielectric substrate. The filter provided by the invention has the advantages of simple structure and easy processing, a frequency band is in a Ku band, the tuning range of the filter reaches 18%, the main mold frequency can be adjusted continuously, and the estimated tuning can be carried out.

The three-port polarizing offset tunable optical filter based on TFF comprises a set or more tunable filter unit with one composed of optical ring connected to the multi channel optical signal input end, a thin film filter, the polarized beam divider A & B on the same light path on the back and forth of the thin film filter plate, featuring in the polarized beam divider A dividing input signal light dividing into P and S parallel lights, with P having half wave plate C rotating P into P-S, two parallel S lights reaching thin film filter plate whose normal line slants on the two parallel S light paths, half wave plate D rotating S into S-P, polarized beam divider B synthesizing P and S into ordinary light signal to output, reflective mirror E paralleling laid with thin film filter plate with reflective mirror F setting behind reflective mirror E with F vertically set with two parallel light paths. It is simple in structure, easy for realization, being able to eliminate polarized relative consumption and polarized light dividing.

Disclosed are a silicon-based mixed and integrated tunable laser and a photon chip. The laser comprises a semiconductor optical amplifier, a silicon-based spot-size converter, a thermal regulation silicon-based annular resonator, a silicon-based phase shifter and a dual-port silicon-based multi-mode interference reflecting mirror which are arranged in sequence; the dual-port silicon-based multi-mode interference reflecting mirror comprises input waveguide, output waveguide, multi-mode waveguide, and conical waveguide for enabling the input waveguide and the output waveguide to be connected with one end of the multi-mode waveguide separately; the input waveguide is connected to the output end of the thermal regulation silicon-based annular resonator; two etching surfaces with an angle of 45degrees with the waveguide axis are arranged at the other end of the multi-mode waveguide; the two etching surfaces are perpendicularly crossed and positioned on the axis of multi-mode interference self-imaging waveguide; and the laser and other silicon-based functional devices form the photon chip. The tunable laser and the photon chip disclosed in the invention have the advantages of small dimension, low cost, easy integration, and wide application prospect in the fields of integrated photoelectronics and optical communication.

The invention relates to a birdcage coil for a magnetic resonance imaging system and a tuning method thereof. The birdcage coil comprises an upper annular conductor, a lower annular conductor and a plurality of linear conductors which are distributed on a cylindrical surface, wherein the linear conductors are connected between the upper annular conductor and the lower annular conductor. A plurality of capacitors are connected in series in the upper annular conductor and the lower annular conductor. The whole or a part of the linear conductor is flexibly bendable and deformable. The distance between the upper annular conductor and the lower annular conductor is changed when the degree of bending deformation of the linear conductor is adjusted so that the resonant frequency of the birdcage coil is changed. The resonant frequency is adjusted by changing the position of a debugging ring. Thus, an expensive adjustable capacitor device is replaced so as to reduce the cost of the birdcage coil. The birdcage coil can be easily debugged at the installation site of the magnetic resonance system. The structure of the whole birdcage coil is adjusted synchronously and a large tuning range is achieved. The distribution of coil current and the uniformity of an RF magnetic field inside the coil are not influenced. The birdcage coil is stable in mechanical structure and can withstand high voltage.

The invention belongs to the technical field of anteannae, and discloses a liquid metal-based frequency- reconfigurable slot couple antenna, which comprises a feed network and a radiating part, The feeding network is a lower layer dielectric substrate, and the radiation part is an upper layer dielectric substrate. A rectangular microstrip patch is printed on the upper surface of the upper dielectric substrate, and a microfluidic channel annular groove filled with liquid metal or Teflon solution is engraved inside the rectangular microstrip patch. The invention adopts liquid metal to realize the reconfigurable characteristic. Compared with the traditional reconfigurable antenna, a pair of antennas can be used to realize the reconfigurable characteristic, and the structure is simple. Liquidmetal reconfigurable is simpler than electronic switch in realizing reconfigurable and wider tuning range. The liquid metal is braked by microfluidic channel, which is easy to realize and control compared with other braking methods. Gallium-indium-tin alloy is used as liquid metal, which is low cost and non-toxic; A large bandwidth is realized by using slot coupling feed.

The invention provides a multiple wavelength convertible tunable fiber laser based on a tapered fiber. The multiple wavelength convertible tunable fiber laser is characterized by comprising a semiconductor laser with a tail fiber, a WDM (wavelength division multiplexer), a single-mode EDF (Erbium-Doped Fiber), a fiber optic isolator, a fiber optic coupler, a fiber optic polarization controller, and a tapered fiber and tuning unit, wherein the tail fiber of the semiconductor laser is connected with the pumping end of the WDM, the output end of the WDM is connected with the output end of the fiber optic isolator through the EDF, the input end of the fiber optic isolator is connected with a port, at which the light splitting coupling ratio is 9, of the fiber optic coupler, a port, at which the light splitting coupling ratio is 1, of the fiber optic coupler is a laser output port, the input end of the fiber optic coupler is connected with the tapered fiber and tuning unit through the fiber polarization controller, the other end of the tapered fiber and tuning unit is connected with the signal port of the WDM, so as to form a closed ring cavity. The multiple wavelength convertible tunable fiber laser based on the tapered fiber, which is provided by the invention, has the advantages of simple method, low cost, compact structure, convertible multiple wavelengths, tunable wavelength, steady operation at room temperature and the like.

The invention discloses a two-dimensional topological photonic crystal cavity, a design method thereof, and application in a laser. The two-dimensional topological photonic crystal cavity comprises aplurality of photonic crystal supercells that have a vortex-type structure change around the cavity center of the two-dimensional topological photonic crystal cavity, and the energy band of the plurality of photonic crystal supercells has a Dirac point at the equilibrium position where the vortex-type structure changes. The two-dimensional topological photonic crystal cavity, also known as a Diracvortex cavity, has the characteristics such as large mode field area, large free spectral range, narrow beam divergence angle, degeneracy of any mode and compatibility with a variety of substrate materials, and can be applied to surface emitting semiconductor lasers to ensure that the laser can still work stably in both single transverse mode and single longitudinal mode when outputting at largearea and high energy.

A circuit is provided wherein the electronic properties of the circuit are varied by a magnetic actuator. The circuit includes a fixed substrate and a movable substrate. The magnetic actuator comprises a magnetic driver on an upper surface of the fixed substrate that is substantially overlapped by an HTS reaction plate on the lower surface of the fixed substrate. A tuning current applied through a continuous strip of HTS material in the magnetic driver induces a repulsive magnetic force causing the movable substrate to move with respect to the fixed substrate.

The invention relates to a tunable interferometer based on a microstructure optical fiber packed by functional material which is composed of a double refraction microstructure optical fiber packed by functional material, a control device, a four-port optical directional coupler, a polarization controller and a circulator. The double refraction microstructure optical fiber packed by functional material is arranged in the control device. Both ends of the microstructure optical fiber packed by functional material are respectively connected with the optical directional coupler and the port of the polarization controller. The ports of the optical directional coupler are connected with the circulator. The two ends of the circulator are respectively the inport and the reflection outport of the interferometer; the port b of the optical directional coupler is the transmission output port of the interferometer. The tunable interferometer has the advantages that compared with the optical fiber ring-shaped mirror interferometer, the interferometer has the strongest points of flexible implementation mode, diversity of tuning modes, wide tuning range, achievable electric tuning and the like, can be applied to the manufacture fields of optical devices such as a tuned filter, an optical switch, a variable optical attenuator, etc.

The invention discloses an inductance coupling plasma processing chamber of an automatic frequency tuning source and a bias radio frequency power source. The inductance coupling plasma processing chamber comprises a processing chamber body, a source radio frequency power source and a bias radio frequency power source, a cathode is arranged at the bottom of an inner cavity of the processing chamber body, a plurality of source coils are arranged at the top of the inner cavity of the processing chamber body, a circuit of the source radio frequency power source is connected with the source coils, a circuit of the bias radio frequency power source is connected with the cathode, the source radio frequency power source and the bias radio frequency power source can realize automatic frequency tuning and can respond to and match with changes of load resistance, the circuit between the source radio frequency power source and the source coils is connected with a matching circuit, the circuit between the bias radio frequency power source and the cathode is connected with a matching circuit, the matching circuit are fixed, the processing chamber body comprises a detection circuit for detecting the load resistance and a control circuit in circuit connection with the detection circuit, and the source radio frequency power source and the bias radio frequency power source are correspondingly in circuit connection with control circuits respectively. The source radio frequency power source and the bias radio frequency power source have functions of automatic frequency tuning, and the source radio frequency power source and the bias radio frequency power source input into the processing chamber body through frequency sweeping and electric tuning are high in tuning speed and wide in tuning range.

A technique for enhancing the frequency tuning range for monolithic RF source generation using fully-integrated coupled Voltage-Controlled-Oscillator (VCO) arrays that contain an odd number of VCOs. Fully-monolithic SiGe VCO arrays using on-chip inductor and varactor with on-chip bias current sources have been carefully designed and simulated in IBM 7HP 0.18 μm BiCMOS technology and taped out for fabrication. The SPICE simulated frequency and phase tuning of the 1-D VCO×5 array is dependent on the edge VCOs termination impedance, the tuning voltages, and the VCO coupling strength. The simulated data suggests that the enhanced tuning range and beam steering can be accomplished using coupled-VCO arrays without needing complex and bulky phase shifters. This design technique imposes no apparent phase noise penalty but can provide simulated RF frequency tuning range of ˜40% and also ˜+ / −25° beam steering for active antennas applications.

The invention provides a terahertz wave tunable mode converter, which comprises a hollow cylindrical metal inner-wall waveguide formed by rectangular periodically fluctuating structures. According to the invention, resonance interaction among different transverse standing wave modes in the waveguide is utilized to realize conversion of terahertz waves from a fundamental mode to a single high-order mode. Furthermore, tuning for output frequency of the terahertz wave mode converter can be realized through changing the thickness of a metal coating in the rectangular periodically fluctuating pipe wall, and the tunable mode converter can realize that the output center frequency is linearly tunable in broadband. The terahertz wave tunable mode converter is reasonable in design, has the characteristics of simple structure, wide tunable range, low loss, high conversion efficiency, convenient integration and the like, can acquire wide applications in fields which have special requirements for terahertz wave mode field distribution and the operating frequency, and provides a new choice for designing and manufacturing functional devices in a terahertz wave application system.

The invention relates to a novel high-performance conformal array antenna, and solves the technical problems of low gain, narrow bandwidth and poor anti-interference capability. The antenna comprisesconformal array antenna units arranged in an array, wherein the conformal array antenna units use a traveling wave antenna feeding structure with two-port feeding, and the size is reduced through thefractal technology, so that the radiation influence of a curved surface on the antenna units is reduced; a slot coupling feed structure is adopted to improve the bandwidth of the antenna units, reducethe surface wave loss of the antenna unit and enable the radiation element to be better isolated from the feed network. A liquid crystal tuning circuit is adopted to apply a liquid crystal material to an antenna unit; the liquid crystal equivalent dielectric constant is changed through electric tuning, so that the resonant frequency of the antenna unit is changed, the radiation characteristic ofthe conformal array antenna unit in a required frequency band is controlled, the contribution of different antenna units to a main wave beam is controlled, the anti-interference capability is enhanced, the problem is better solved, and the conformal array antenna can be used in an antenna.

The invention discloses a broad-tuning waveguide terahertz radiation source. The broad-tuning waveguide terahertz radiation source comprises a laser pump source, a dual-wavelength parametric oscillator, a cylindrical lens and a panel waveguide, wherein the laser pump source outputs 532nm Q-switched pulses to the dual-wavelength parametric oscillator, the dual-wavelength parametric oscillator generates dual-wavelength pulses which are within the range, wherein the center of the range is a degeneracy point, and the radius of the range is 1064nm, the dual-wavelength pulses are focused through the cylindrical lens, and are coupled to a core layer of the panel waveguide, narrow-linewidth THz waves are generated through the second-order non-linear difference frequency effect, a THz radiation mode is generated through the Cherenkov phase matching mode, and sidewise coupling output is achieved. Due to the fact that the structure is adopted, the tuning range is expanded, broadband tuning within the range from 0.1THz to 7THz can be achieved, high-efficiency coupling of the THz waves is achieved, coherent THz radiation output with broad tuning and the narrow linewidth is finally achieved, and the broad-tuning waveguide terahertz radiation source can be widely applied to the fields such as the biomedicine imaging field, the high-resolution spectral analysis field, the material detection field and the medical diagnosis field.

The invention provides a broad tuning terahertz wave generator based on Doppler frequency modulator cyclic frequency shift. The broad tuning terahertz wave generator comprises a laser, a circulator, a beam splitter, a cyclic frequency shift link based on the Doppler frequency modulator frequency shift, a beam combiner, an optical isolator and a photoelectric converter with a terahertz radiating antenna. Light emitted by the laser is split into a first path and a second path by the beam splitter after passing through the circulator, wherein the first path is reference light, and the second light is input into the cyclic frequency shift link to generate cyclic frequency shift light. The reference light and the cyclic frequency shift light are superposed by the beam combiner to generate beatfrequency light within a terahertz frequency range. The beat frequency light is received by the photoelectric converter with the terahertz radiating antenna after passing through the optical isolator, and coherent terahertz waves are radiated. The generator provided by the invention has a small volume, a wide tuning range, high tuning efficiency and high terahertz generation efficiency, and is easy to integrate due to fewer optical elements.

The invention discloses a frequency-adjustable and power-tunable terahertz avalanche oscillator. An oscillation cavity of the terahertz avalanche oscillator is formed by combining an upper cavity body and a lower cavity body, wherein a waveguide slot is formed in the top surface of the cavity body of the lower cavity body, and the waveguide slot is combined with the upper cavity body to form a standard waveguide cavity; an avalanche diode is assembled in a waveguide cavity in the center of the top surface of the lower cavity body through a tube base assembly thimble, the high and low positions of the avalanche diode in the waveguide cavity can be adjusted through rotating the tube base assembly thimble, and the avalanche diode is fixed through a locking nut after being adjusted in position; a spring thimble, a spring and a tunable cap disc are sequentially mounted in a tuning plunger from top to bottom, the tuning plunger assembled with the tunable cap disc, the spring and the spring thimble is screwed from an upper cavity pressure block to directly reach the waveguide cavity, and the spring enables the tunable cap disc to constantly keep physical contact with the avalanche diode in different high and low positions; the position of the tuning plunger is fixed through a piston locking nut.

The invention relates to a half mode substrate integrated waveguide (HMSIW) filter with adjustable central frequency and bandwidth. The HMSIW filter formed by laminating two layers of dielectric-slabs is utilized, the area of an upper-layer dielectric-slab is larger than that of a lower-layer dielectric-slab, a physical space is provided for loading of a tuning element, and the tuning of the central frequency and the bandwidth is achieved by loading a varactor; a metal layer of the upper-layer dielectric-slab is sunken, and a sunken part metal layer and a metal layer of the lower-layer dielectric-slab form a relatively high capacitance effect; the reduction of the resonant frequency is not dependent on the increase on the size of a resonant cavity any longer, the frequency is tuned by the varactor externally loaded and connected in parallel, a frequency tuning mode of an SIW structure is creatively achieved; and meanwhile, with the introduction of an HMSIW, the requirement of a modern radio frequency communication system on miniaturization is met, and the problem that a traditional cavity filter is difficult to tune by externally loading a tuning element is solved.

The invention discloses an integrated inductance capacitance voltage-controlled oscillator comprises four programmable negative resistance type LC (inductance capacitance) oscillating core circuits, a public output stage and a current amount programmable offset module, wherein the public output stage is connected with the four programmable negative resistance type LC oscillating core circuits; and the current amount programmable offset module is connected with the four programmable negative resistance type LC oscillating core circuits through a controlled switch. Compared with the common voltage-controlled oscillator, the integrated inductance capacitance voltage-controlled oscillator has obvious disadvantages in debugging range, phase noise, and other aspects; and in addition, the invention is specially suitable for a demanding multistandard multiband radio-frequency radio communication system.

The invention discloses a device and method for generating a four-frequency-doubling signal and realizing microwave photon phase shift based on a double-parallel modulator, and relates to the technical field of microwave and optical communication. The device and method are mainly applied to microwave photon signal processing. As shown in figure, the device comprises an adjustable laser source (TLS), a dual-parallel modulator (DPMZM), an erbium doped fiber amplifier (EDFA), an optical loop (OC), a Prague fiber grating (FBG), a Faraday rotating mirror (FRM), a polarization controller (PC), a polarizer (Pol) and a photoelectric detector (PD). According to the method, a positive and negative two-order band optical signal for orthogonal polarization multiplexing is obtained by using DPMZM, FBGand FRM, and the 360-degree continuous phase shift while keeping basically unchanged amplitude of a microwave signal is achieved. In addition, the scheme further has the advantages of wide tuning range, simple structure, strong operability, and can be used for multi-channel applications.

The invention discloses a tunable terahertz waveguide filter based on a bimorph thermal actuator. The tunable terahertz waveguide filter comprises an E surface longitudinal diaphragm, the bimorph thermal actuator and a rectangular waveguide, wherein the E surface longitudinal diaphragm is horizontally installed in the middle of the inner cavity of the rectangular waveguide; and the bimorph thermal actuator is horizontally installed at the bottom of the inner cavity of the rectangular waveguide and positioned below the E surface longitudinal diaphragm. The E surface longitudinal diaphragm and the bimorph thermal actuator are installed inside the inner cavity of the rectangular waveguide, so that the tunable terahertz waveguide filter has the advantages of high working frequency, wide tuning range, easiness in manufacturing, strong universality and the like and has a good application prospect in a terahertz system.