233 results about "Gain bandwidth" patented technology

A pipelined analog-to-digital converter features an amplifier block that includes a switching network to implement a double sampling and double conversion principle of operation. The amplifier block utilizes both phases of a clock for sampling and conversion. Additionally, each stage of the analog-to-digital converter is associated with two independent processing blocks. The analog-to-digital converter can achieve double throughput for approximately the same level of power consumption. Alternatively, throughput may be maintained, but the gain-bandwidth of the amplifier block may be reduced by half, thereby halving the DC bias current consumed by the amplifier. Additionally, the output signal of the amplifier itself is not reset to a common mode voltage.

Methods and apparatus for regulating a synchronous rectifier DC-to-DC converter by adjusting one or more existing synchronous rectifiers in the converter are provided. By regulating an existing synchronous rectifier, the rectifier may function as a modulator for post regulation over a limited range of output voltages suitable for load regulation, without introducing an additional conversion stage for post regulation, which typically decreases efficiency and power density. Independent post regulation of an existing synchronous rectifier may improve the load regulation, reduce output voltage ripple, and improve the transient response of the converter. By operating independently from the main control loop, post regulation may most likely avoid the limitations of the main control loop, such as limited gain bandwidth and a relatively slow transient response. Such post regulation may be added to isolated or non-isolated switched-mode power supplies, such as forward or buck converters.

A low voltage differential linear regulator utilizes an embedded compensation network in an amplifier to improve performance, which embeds a compensation network composed of resistances and capacitances into an amplifier to increase one or a plurality of pole-zero pairs with their pole-zero frequency lower than pole frequency in a transfer function of a feedback loop without changing static operating point of the amplifier and increasing static current. Frequency of the pole-zero pairs can be accurately confirmed to enhance stability of the feedback loop of the low voltage differential linear regulator, expand loop unit gain bandwidth and increase phase margin and DC and low-frequency gain of the loop, thus enhancing performance of the low voltage differential linear regulator.

The invention provides a phase delay linetype reflector element based reflective array antenna. The reflective array antenna comprises a pyramid horn feed source and a reflector array, wherein the reflector array is formed by periodically arranging a plurality of phase delay linetype reflector elements in a mirror symmetry manner; and the phase delay linetype reflector element structure comprises two slotting circular ring nests and two phase delay lines that are in opposite in positions. The gain bandwidth of the reflector array antenna is greatly increased, an ultra wide band antenna is realized, and cross polarization is effectively restrained as well; and in addition, the reflection array antenna provided by the invention adopts a single-layer dielectric substrate structure, so that the reflector array is simple in structure, easy to process, low in cost and light in weight.

The invention discloses a broadband foldable reflective array antenna, and belongs to the technical field of antennas. The broadband foldable reflective array antenna employs a foldable reflective array antenna structure, and provides a brand new reflective array unit, so that the foldable reflective array of the reflective array unit solves the problem that breakthrough on gain bandwidth of a conventional foldable reflective array antenna is hard to achieve. The characteristics of high gain, low loss, compact structure and low cross polarization of a foldable reflective array antenna are fully explored. The broadband foldable reflective array antenna is suitable for microwave, millimeter wave, THz frequency ranges and applicable to high performance communication or radar systems.

A laser system includes an injection laser source having an output and operable to provide a laser output characterized by a first wavelength, a first linewidth, an output power. The laser system also includes a tunable pulsed source characterized by a gain bandwidth. The tunable pulsed source is operable to provide an output signal having an average power. The output signal includes a plurality of optical pulses. Each of the plurality of optical pulses is characterized by a second wavelength, a second linewidth, and a peak power. The laser system further includes an optical combiner having a first port coupled to the output of the injection laser source, a second port coupled to the tunable pulsed source, and a third port.

The invention discloses a method for compensating the frequency of a broadband common mode feedback ring circuit for a two-stage operational amplifier, belonging to the field of analog integrated circuit design. A broadband feedback amplifier in the two-stage operational amplifier with the Miller compensation is used as the common mode feedback ring circuit so as to reduce the area and the power consumption of the common mode feedback circuit; the two-stage operational amplifier has only one main pole in the range of the unit gain bandwidth, a fully differential input and output structure is adopted, the sampling of the common mode output level is performed by the differential output end; and a control signal fed back by the common mode simultaneously controls the output level of a first-stage common mode and the output level of a second-stage common mode of the operational amplifier through a controllable bias circuit. The frequency of the main pole of the broadband feedback amplifier is far higher than the unit gain bandwidth of the operational amplifier, therefore the margin of phase position of the common mode ring circuit is basically equal to that of the operational amplifier, thereby forming the stable feedback ring circuit. The method has the advantages of few elements for a common mode feedback circuit, lower power consumption of the common mode feedback circuit and simpler and more convenient circuit design.

The invention discloses a gain bootstrap type C class reverser and an application circuit thereof. Based on a C class reverser 32 in the prior art, the gain bootstrap type C class reverser is additionally provided with micropower gain bootstrap modules 30 and 31 and bulk potential modulation modules 33 and 34, wherein the gain bootstrap modules 30 and 31 greatly improve the steady-state gain of the C class reverser under the condition of not losing the output swing or increasing the circuit power consumption significantly so as to improve the integral precision of a gain bootstrap type C class reverser-based pseudo-differential structure switched capacitor integrator and the analog-to-digital conversion precision of an analog-to-digital converter, and broaden the application range of the C class reverser; and the bulk potential modulation modules 33 and 34 make the steady-state characteristics (gain, bandwidth, static power consumption and the like) and the dynamic characteristics (slew rate, setting time, dynamic power consumption and the like) of the whole reverser consistent under the condition of different corners, and greatly improve the stability and the robustness of the application circuit of the gain bootstrap type C class reverser under the condition of not increasing the power consumption significantly.

The invention discloses a novel broadband low-profile dielectric lens antenna, and belongs to the technical field of microwave. The antenna feed source part of the lens antenna comprises two layers of dielectric plates; rectangular gaps in the metal grounding surface of the bottom layer dielectric plate of the feed source are coupled with square patches on the upper layer dialectic plate through an air layer to generate polarized wave; a novel cavity-free part reflective surface consists of two layers of frequency selection surfaces with dielectrics, and the reflective phases are changed along with frequencies in a positive slope manner and are matched with the feed source antenna so as to greatly improve the 3dB gain bandwidth of the antenna finally; by virtue of the cavity-free part reflective surface, the profile height of the resonant cavity antenna is lowered, so that the low profile characteristic of the antenna is realized; in addition, the reflective coefficient of the novel part reflective surface is higher than that of the similar type surface, so that the working frequency band gain of the antenna is improved stably; and in general, the design has certain application prospect.

A LDO circuit using two-way asymmetry buffer mechanism to improve performance. The two-way asymmetry buffer mechanism is adopted, at the same time, a feedback circuit with signal back function and a forward passage with signal direct function are adopted; the feedback circuit is used for realizing a frequency compensation of the LDO circuit and improving temporal response performance; the forward circuit is used for counteracting a right half-plane zero point generated by a grid leak parasitic capacitance of a LDO transfer component so as to improve the stability of the system and gain bandwidth of an expanded unit. This circuit has advantages of simple structure, low energy consumption, and effectively removing the right half-plane zero point.

A digital signal channel bypass is provided as bypass around an optical network optical amplifier, in particular, an analog type optical amplifier, such as an EDFA, in an optical transport network or system. The digital signal bypass provides for an ability to maintain the existing optical amplifier OO amplification site while inserting a bypass that provides ultra low-cost OEO REGEN in a digital optical network (DON) utilizing both semiconductor electronic integrated circuit chips and semiconductor photonic integrated circuit (PIC) chips where all the optical components are in semiconductor integrated chip form providing 1R, 2R, 3R or 4R regeneration as well as other signal caring functionality. A salient feature of the digital signal bypass is to regenerate signals in the optical span that are outside the gain bandwidth of the EDFA or other such amplifier.

A multicolor photonic crystal laser array comprises pixels of monolithically grown gain sections each with a different emission centre wavelength. As an example, two-dimensional surface-emitting photonic crystal lasers comprising broad gain-bandwidth III-nitride multiple quantum well axial heterostructures were fabricated using a novel top-down nanowire fabrication method. Single-mode lasing was obtained in the blue-violet spectral region with 60 nm of tuning (or 16% of the nominal centre wavelength) that was determined purely by the photonic crystal geometry. This approach can be extended to cover the entire visible spectrum.

The present invention relates to a miniaturized top-loaded double-frequency quadrifilar helix antenna and a working method thereof. The miniaturized top-loaded double-frequency quadrifilar helix antenna comprises a radome, a helix antenna main body, a feed network and active amplification circuit, a shielding cavity, a pedestal and a coaxial lead. One end of the coaxial lead is in contact connection with the feed network and active amplification circuit, and the other end of the coaxial lead is connected with a receiving module; the feed network and active amplification circuit is connected with the helix antenna main body; the radome is detachably connected with the pedestal up and down; the shielding cavity is connected with the feed network and active amplification circuit; the helix antenna main body comprises two sets of quadrifilar helix antennas, wherein the first set of quadrifilar helix antenna is configured to excite low frequency, and the second set of quadrifilar helix antenna is configured to excite high frequency; and each set of quadrifilar helix antenna is formed by spiralling four spiral arm units with the same structure at intervals in the same direction. The miniaturized top-loaded double-frequency quadrifilar helix antenna and the working method thereof are compact in structure, expand working frequency bands without increasing the volume of the antenna, improve the gain bandwidth and achieve miniaturization.

The present invention relates to Erbium Ytterbium codoped multi-component oxide glass monomode fiber core glass and a method for preparing monomode fiber. The core glass comprises SiO2, Al2O3, Li2O, Yb2O3, Er2O3, B2O3, etc. A round bar is made from Erbium-doped glass blank, a core glass is formed by drawing it into a thin round bar; another round bar is made from non-Erbium-doped glass blank, a cladding glass is formed by laser punching it; the thin round bar is placed in the hole of the cladding glass to form an Erbium-doped optical fiber performrod; then a monomode fiber is obtained by drawing the performrod in a wire drawing furnace. The invention solves the problems in the prior art of uneven gain spectrum, narrow gain bandwidth, complicated preparing technology and so on. The Erbium Ytterbium codoped multi-component oxide optical glass fiber can provide transmission bandwidth of 60nm and more even gain spectrum, higher glass transition temperature, better chemical and heat stability, can satisfy the increased requirements of the current optical transmission network.

The invention discloses a tunable ytterbium-doping double-clad fiber mode-locked laser which belongs to the technical field of lasers. The tunable ytterbium-doping double-clad fiber mode-locked laser is in an annular cavity structure, takes a large-core diameter double-clad ytterbium-doping fiber as a gain medium and works on a total positive dispersion area. The tunable ytterbium-doping double-clad fiber mode-locked laser realizes the mode locking self-starting and stably carries out mode locking by dint of a nonlinear polarization rotation technology and a spectrum filter, is adjustable in filtering bandwidth because the spectrum filter comprises a grating and a slit with adjustable width, has a tuning function and can continuously tune the center wavelength of an output pulse within a gain bandwidth range. The tunable ytterbium-doping double-clad fiber mode-locked laser disclosed by the invention realizes the total positive dispersion mode locking of the large-core diameter double-clad fiber by adopting nonlinear polarization rotation and a spectrum filter technology, obtains the ultrashort-pulse laser output supporting high power and high single-pulse energy, is continuously tunable in center wavelength and is convenient to operate and large in tuning range by composing the spectrum filter by adopting the grating and the slit.

The invention discloses an air-coupled low-profile circularly-polarized dielectric lens antenna. The air-coupled low-profile circularly-polarized dielectric lens antenna is composed of three layers of dielectric plates, a square metal layer is arranged on the upper surface of the dielectric plate on the top layer, and a periodic rhombus gap is further formed in the square metal layer; a metal patch in the shape of an equilateral triangle is arranged on the lower surface of the dielectric plate on the middle layer, and the center of the metal patch is overlapped with the center of the dielectric plate on the middle layer; a microstrip line for feeding extending to the center along one side of the dielectric plate on the bottom layer is arranged on the lower surface of the dielectric plate on the bottom layer; the upper surface of the dielectric plate on the bottom layer is covered with a metal layer as an earth plate, and a cross-shaped gap is formed in the central position of the earth plate. According to the air-coupled low-profile circularly-polarized dielectric lens antenna, the impedance bandwidth, gain bandwidth and circular polarization bandwidth of the dielectric lens antenna are greatly improved. Moreover, through the design of a partial reflection surface, the reflection phase of the partial reflection surface in an antenna working frequency band is reduced, so that the height of the antenna is reduced, and low profile of the antenna is realized.

The invention discloses a low-power-consumption wide-range operational transconductance amplifier which comprises a first stage of differential input stage, a second stage of differential input stage, a gain stage, an output stage and a self-biased circuit. An input signal is input into an input end of the first stage of differential input stage; a bias voltage vb3 loaded to the first stage of differential input stage is generated by the self-biased circuit; an output end of the first stage of differential input stage is connected to an input end of the second stage of differential input stage; bias voltages vb1 and vb2 required by the second stage of differential input stage are generated by the self-biased circuit; an output end of the second stage of differential input stage is connected to an input end of the gain stage; and an output end of the gain stage is connected to an output amplifier in the output stage and a compensation and overcurrent protection circuit. The low-power-consumption wide-range operational transconductance amplifier has the beneficial effects that 1, the low-power-consumption wide-range operational transconductance amplifier has lower power consumption; 2, the low-power-consumption wide-range operational transconductance amplifier has a wider input and output range; and 3, the low-power-consumption wide-range operational transconductance amplifier has a higher gain bandwidth.

A method and apparatus is provided for improving at least one gain bandwidth path. At least one signal being transmitted is monitored. A gain / bandwidth control process is performed upon the monitoring of the signal. The apparatus taught by the present invention comprises: a first circuit portion capable of driving a signal onto a subscriber line; and a second circuit portion electrically coupled with the first circuit portion, wherein the second circuit portion is capable of separating a plurality of signal paths based upon at least one characteristic of the signal path for applying an appropriate gain factor upon the signal path.

Dual amplifying circuits having a magnetic tunnel junction device and a field effect transistor configured in a complementing set are disclosed herein. In one embodiment, the field effect transistor is operable to control a current level of a current operating signal flowing through the magnetic tunnel junction device. In another embodiment, the magnetic tunnel junction device is operable to control a voltage level of a voltage signal being applied to a gate terminal of the field effect transistor. The gain-bandwidth product of both embodiments is greater than the individual gain-bandwidth products of the individual devices through the elimination of noise contributing resistive type circuit elements.

The invention relates to the technical field of laser, and provides a broadband optical parameter chirped pulse amplifier. The broadband optical parameter chirped pulse amplifier comprises a narrow-band picoseconds laser device, a pulse laser stretcher, an optical coupling mirror, a beam expanding / contracting system, periodic poling crystal, a spectroscope and a pulse laser compressor. The periodic poling crystal with the periodic domain inversion structure is used for separating generated idler frequency light from chirped pulse laser / pumping light to inhibit energy backflow after the broadband optical parameter chirped pulse amplifier is in a saturated amplification state, and therefore broad optical parameter chirped pulse amplification of a broadband is achieved. The broadband optical parameter chirped pulse amplifier is capable of inhibiting backflow of signal light energy and has extremely wide gain bandwidth, benefited from synchronous optimization of pulse energy (conversion efficiency) and pulse width (gain bandwidth), outputable peak-peak power of the broadband optical parameter chirped pulse amplifier is greatly promoted, and performance of the broadband optical parameter chirped pulse amplifier is improved.

The invention discloses a broadband low-loss passive balun on chip having a laminated winding structure. The balun on chip is provided with three layers of metal conducting wires. The metal conducting wires in a first layer are secondary conducting wires, the metal conducting wires in a second layer are primary conducting wires and the metal conducting wires in a third layer are ground wires. U-shaped continuous bent winding structures are formed between the heads and tails of the conducting wires of each layer. The geometrical shapes of all U-shaped bends are completely consistent. The U-shaped bends are broken from midpoints between the heads and tails of the secondary conducting wires in the first layer to form left and right discontinuous U-shaped bend sections. Single-end signals of an unbalanced end are connected with the heads of the primary conducting wires. The tails of the primary conducting wires are connected to the ground wires. The heads and tails of the secondary conducting wires are all connected with the ground wires. Breakpoints of the conducting wires in the same sections with the heads of the secondary conducting wires are normal phase signal output ends, and the breakpoints of the conducting wires in the same sections with the tails of the secondary conducting wires are inverted signal output ends. The single-end signals of the unbalanced end are convertedinto differential signals of a balanced end for output under the coupling action of the primary and secondary conducting wires. The ground wires reduce the insertion loss of the balun and simultaneously expand a gain bandwidth and a matched bandwidth.

The invention discloses a broadband string series-feed circular polarization patch antenna. The broadband string series-feed circular polarization patch antenna is provided with a rectangular radiation medium substrate, wherein the rectangular radiation medium substrate comprises a small square radiation metal patch on an upper surface and a large square radiation metal patch on a lower surface, the upper and lower surface of the rectangular radiation medium substrate are respectively printed with a rectangular sheet metal and a series-feed microstrip line, a tail end of the series-feed microstrip line is connected with the rectangular sheet metal through a load resistor, and the rectangular sheet metal is provided with N sets of rectangular metal slits through etching. The broadband string series-feed circular polarization patch antenna is advantaged in that a serial traveling wave feed structure integrating the series-feed microstrip line and the load resistor is employed, an antenna feed network is simplified, and the antenna is convenient for making and processing; the two radiation metal patches with different sizes are employed to widen radiation gain bandwidth of the antenna; the two rectangular metal slits of which directions are perpendicular mutually are arranged below the large square radiation metal patch, phase difference of the two rectangular metal slits is 90 DEG, an antenna array element axial ratio is made to be a relatively small value, and thereby an antenna axial ratio bandwidth is substantially improved.

The invention relates to a differential operational amplifier by using active feed-forward circuit for frequency compensation, and mainly solves the technical problems that the zero pole separation of a multistage differential operational amplifier is caused as the current Miller frequency compensation method introduces Miller capacitance, and further unity-gain bandwidth of the differential operational amplifier is limited. According to the technical scheme, the differential operational amplifier comprises a first gain stage, a second gain stage and an active feed-forward amplification stage, wherein each of the first gain stage and the second gain stage comprises a first input node and a second input node; the active feed-forward amplification stage is composed of a circuit A (a control node is coupled to the first input nodes, and a control path is coupled to a second output node;) and a circuit B (a control node is coupled to the second input nodes, and a control path is coupled to a first output node;). The differential operational amplifier further comprises a common-mode negative feedback circuit, wherein the common-mode negative feedback circuit is composed of a high gain stage and an active feed-forward amplification stage. The unity-gain bandwidth performance of the fully differential operational amplifier can be effectively improved, and chip implementation area is reduced.

The present invention provides a circuit and a method for promoting bandwidth enhancement of a low noise amplifier. The circuit includes a first transistor including a first gate, a first drain, and a first source; a second transistor including a second gate, a second drain, and a second source, wherein the first transistor and the second transistor form a cascode topology; and a transformer, which is embedded in the second gate of the second transistor and the second drain between the terminals. The conventional source-to-cathode feedback cascode low-noise amplifier is extended to a wide gain bandwidth by embedding a transformer between the gate and drain of a common-gate transistor. The embedded transformer can introduce an additional pair of high-frequency conjugate poles that can push the gain drop start to a higher frequency, peaking a higher frequency gain, thereby broadening the amplifier gain bandwidth.

The invention provides a control device of a power factor correcting circuit and a control method. The power factor correcting circuit (200) is driven by the input of an input circuit (100), the control device comprises a sampling circuit (300), a driving circuit (400) and a control circuit (500), wherein the control circuit (500) comprises a processing unit (510), the sampling circuit (300) acquires the status signal of the power factor correcting circuit (200), and sends the signal to the processing unit (510), the processing unit (510) controls the output parameters of the control circuit (500) according to the status signal so as to control the driving circuit (400), and the driving circuit (400) outputs corresponding driving signals so as to control the power factor correcting circuit (200). The invention has the advantage that the control has sufficient phase margin, wide gain bandwidth and high gain.