33results about How to "Wide gain bandwidth" patented technology

The invention provides a broadband CMOS (Complementary Metal-Oxide-Semiconductor Transistor) balun low noise amplifier which aims at disadvantages of a traditional cascode balun amplifier. The broadband CMOS balun low noise amplifier is formed by a cascode input stage, a differential common gate isolation stage and a resistive load stage; the cascode input stage is formed by a cascade stage resistor, a first capacitor, a second capacitor, a first NMOS (N-channel metal oxide semiconductor FET) pipe and a second NMOS pipe which adopt a connecting mode through capacitance cross coupling and body cross coupling; the differential common gate isolation stage is formed by a third capacitor, a fourth capacitor, a third NMOS pipe and a fourth NMOS pipe which adopt a connecting mode through capacitance cross coupling; the resistive load stage is formed by a common gate branch circuit load resistor RCG and a common source branch circuit load resistor RCS. The broadband CMOS balun low noise amplifier has the advantages of improving circuit gain and noise performances, improving differential output balance and eliminating dependence on off-chip inductance and on-chip inductance in a large area on the basis that broadband characters and single-end-differential conversion are guaranteed.

A series-fed E-shaped patch antenna array has co-polarized parasitic patches to improve aperture efficiency. Each of microstrip parasitic patches is inserted between a plurality of microstrip E-shaped patch antennas. The parasitic patches are co-polarized with the E-shaped patch antennas so that the current flows in the parasitic patches and the E-shaped patch antennas have the same polarity. Additional radiation from the co-polarized microstrip parasitic patches significantly improves gain flatness, gain and aperture efficiency due to offset resonance frequency.

The invention discloses a micro-strip reflective array antenna, and mainly solves problems in the prior art that the structure is complicated and the bandwidth is narrower. The micro-strip reflectivearray antenna is formed by periodically arranging a plurality of horizontally and longitudinally uniformly arranged paster units. A reflecting phase of each paster unit is different, and an arrangement period D is 0.3-0.5 Lambda. Each unit successively comprises a paster (1), a medium substrate (2) and a floor (3) from top to bottom. The paster (1) uses a circular structure. The circular paster isprovided with two pairs of gaps (11). The two pairs of the gaps (11) are positioned at two ends of two mutual perpendicular diameter lines of the circle. The micro-strip reflective array antenna is capable of improving the gain bandwidth, simple in structure, smaller in cross-polarization, and good in unit frequency characteristic curve parallelism, and can be used for the electromagnetic wave regulation and control of a microwave band.

The invention discloses a reflective array radiating element and belongs to the technical field of antennas. The reflective array radiating element comprises a dielectric substrate and a metal pattern layer printed on one side of the dielectric substrate. The metal pattern layer is in a multi-ring nested structure, comprising a plurality of phase factor adjusting rings and a plurality of phase compensation rings located outside the phase factor adjusting rings. The use of the single-layer printed structure allows easier process of the multi-layer printing technique, lower dielectric loss and lower processing cost; compared with the traditional unit, the reflective array radiating element is 4 to 6 times higher in phase compensating capacity, and the focus-diameter ratio of the traditional reflective array is decreased to 0.5 and even lower; on the whole operating band, the optimal structural size can be provided for each reflective array unit, the phase of each reflective array unit is compensated as required, and gain bandwidth of a reflective array antenna is expanded. The invention further discloses a planar reflective array antenna comprising the reflective array radiating element.

The invention provides bismuth-doped silicophosphate-based optical glass and a preparation method thereof. The preparation method comprises the following steps of: uniformly mixing the following components in percentage by mole: 34.9-64.9 percent of SiO2, 8-20 percent of P2O5, 15-35 percent of Al2O3, 15-45 percent of RO and/or RCO3 and 0.1-5 percent of Bi2O3; heating the mixture to 1,300-1,600 DEG C, preserving heat for 30-180 minutes and melting the raw material to be in a liquid state; and annealing at 500-650 DEG C for 0.5-6 hours, and naturally cooling to room temperature to obtain the bismuth-doped silicophosphate-based optical glass. The bismuth-doped silicophosphate-based optical glass has the ultra-broadband optical performance of covering an entire communication waveband, the melting temperature is remarkably lowered relative to quartz glass, and the viscosity of the melting liquid in the melting process of the glass is lowered, so that the defects (such as air bubbles and the like) in the melting and molding processes of the glass are reduced compared with those of quartz glass, the mechanical performance of the glass is improved, and infrared illumination intensity of bismuth in the glass is high.

The invention discloses a circularly polarized microstrip patch antenna. The antenna comprises a conductive grounding plane, a dielectric substrate arranged on the conductive grounding plane, a radiation sheet arranged at the top of the dielectric substrate and a plurality of feed probes arranged on the side walls of the periphery of the dielectric substrate; the dielectric substrate comprises a lower-layer high-dielectric-constant dielectric substrate and an upper-layer low-dielectric-constant dielectric substrate; the radiation sheet is a sheet-shaped circular metal conductor; and a gear-shaped opening of a symmetrical structure is formed in the middle of the radiation sheet. A gradient folding type side coupled feed mode is adopted; the feed probes are gradually bent; the processing issimple; relatively wide bandwidth is easily formed; the circular polarization performance of the antenna is improved; the phase center is stable; right-handed and left-handed circular polarization canbe realized at the same time; the antenna is especially suitable for accurate measurement and guidance system terminal equipment; the two dielectric substrates with different dielectric constants areadopted; and the designed antenna is small in size, light in weight and wide in gain bandwidth which can reach more than 25%.

Quasi-parametric chirped-pulse amplifier comprising a signal path, a pump path, and an amplifier. A dedicated nonlinear crystal doped with rare-earth-ions is used which has strong absorption around the idler waveband. Both the chirped signal pulse and the pump pulse incident into the amplifier, where energy continuously transfers from the pump pulse to the signal pulse and a newly generated idler pulse. The energy of the generated idler pulse is continually absorbed by the rare-earth ions doped in the amplifier.

The invention relates to an ultrashort pulse laser generating an amplification structure based on stimulated Raman scattering. The ultrashort pulse laser comprises a pumping source; a beam splitter; a reflector; a convex lens; an SRS generation pool; a first dichroscope; an SRS amplification pool; a second dichroscope; the pumping source emits single longitudinal mode pumping light which is divided into two beams by the beam splitter; the first light beam is focused and reflected by a convex lens and a first dichroscope to enter an SRS generation pool for backward stimulated Raman scattering, and reverse Stokes seed light is generated and enters an SRS amplification pool through the first dichroscope; the second light beam is reflected by the reflector and the second dichroscope and then enters the SRS amplification pool to oppositely meet the reverse Stokes seed light, and the reverse Stokes seed light extracts the energy of the second light beam for amplification; and the compressed and amplified ultrashort pulse Stokes seed light is output through the second dichroscope. Pump light is compressed and amplified through the structure, high energy output can be obtained, and compared with a mode-locked laser, picosecond laser of tens of millijoules can be directly generated.

The invention discloses a wideband differential-to-single-end amplifier, overcoming deficiencies of a traditional amplifier of a common-gate structure and an LC Balun. The amplifier comprises an input unit, a choke unit, a filter unit, an amplification unit and a Balun unit, wherein positive and negative ends of a differential radio frequency input signal are respectively connected with a positive input end Vin+ and a negative input end Vin- of the input unit, the input end of the input unit is connected with the choke unit, the output end of the input unit is connected with the input end of the filter unit, the output end of the filter unit is connected with the input end of the amplification unit, the output end of the amplification unit is connected with the Balun unit, and the Balun unit outputs a single-end radio frequency output signal. According to the amplifier provided by the invention, power consumption of the amplifier can be reduced, and gain, isolation and phase balance of the amplifier can be improved on the basis of ensuring wideband characteristics.

The invention discloses a high-bandwidth SIW circularly polarized filtering antenna which sequentially comprises a first metal layer, a first dielectric layer, a second metal layer, a second dielectric layer, a third metal layer, a third dielectric layer and a fourth dielectric layer from bottom to top. Wherein the second metal layer is provided with a plurality of radiation windows; a semicircular gap is formed in the third metal layer, and a semicircular first microstrip patch is nested in the semicircular gap; and a third SIW resonant cavity is formed on the fourth dielectric layer, a plurality of second microstrip patches correspondingly overlapped with the radiation windows are arranged in the third SIW resonant cavity, and the second microstrip patches have a certain deflection angle relative to the vertical direction. According to the high-bandwidth SIW circularly polarized filtering antenna provided by the invention, the radiation characteristics of circular polarization and band-pass filtering are realized on the basis of miniaturization, in addition, relatively wide gain bandwidth and axial ratio bandwidth are also obtained, and the problems of relatively narrow bandwidth and limited application range of a circularly polarized filtering antenna in the prior art are solved.

The invention provides a non-self-complementary broadband antenna. The non-self-complementary broadband antenna comprises a monopole antenna, a slot antenna, a metal ground and a feed device, the monopole antenna is connected with the feed device; the feed device is used for providing a radio frequency signal for the monopole antenna, and the monopole antenna is used for radiating electrical measurement waves to the outside; the monopole antenna and the slot antenna are both arranged on the metal ground; the slot antenna is used for radiating electrical measurement waves to the outside. By means of the relation between the input impedance of the monopole antenna and the input impedance of the half-slot antenna, wide impedance bandwidth and gain bandwidth are achieved.

A fiber amplifier that is particularly configured to provide gain across a large extent of the C-band spectral range (i.e., a gain bandwidth of at least 42 nm, preferably within the range of 46-48 nm) utilizes a specially-designed discrete Raman amplifier in combination with a high inversion level EDFA to extend the gain bandwidth of a conventional EDFA C-band optical amplifier, while maintaining the gain ripple below an acceptable value. The EDFA provides operation at a highly-inverted level and the specialized discrete Raman amplifier (sDRA) element has particular parameters (dispersion, length, effective area) selected to maintain operation within a “small gain” regime while also extending the long wavelength edge of the gain bandwidth and reducing the gain ripple attributed to the EDFA component.

The invention provides an optical fiber femtosecond laser oscillator, which is characterized in that a pump laser (6) and a pump laser (7) respectively pump a first optical fiber (2) and a second optical fiber (3) to generate wide-spectrum emergent light, the emergent light is adjusted into a multi-wavelength light beam which is linearly distributed in space through a dispersion control device (4), the multi-wavelength light beam passes through a reflection end mirror (5) and then carries out spectrum screening on the emergent light again, the light beam subjected to spectrum screening is transmitted to a mode locking device (1) through the dispersion control device (4), the second optical fiber (3) and the first optical fiber (2) in sequence, the mode locking device (1) fixes the phase relation of the emergent light and compresses the pulse width, and the emergent light is emitted to obtain femtosecond-magnitude light pulses. According to the optical fiber femtosecond laser oscillator provided by the invention, the gain bandwidth of the femtosecond laser oscillator is expanded by adding a new gain medium in the oscillator, so that femtosecond laser pulse output with wider spectrum and narrower pulse width is output.

The invention discloses an automatically-adjusted variable gain amplification circuit and an implementation method thereof. The circuit comprises an input impedance matching circuit, a negative feedback control voltage conversion circuit, a main body operation amplification circuit and an output matching circuit, wherein the output end of the input impedance matching circuit is connected with theinput end of the negative feedback control voltage conversion circuit, the output end of the negative feedback control voltage conversion circuit is connected with the input end of the main body operation amplification circuit, and the output end of the main body operation amplification circuit is connected with the input end of the output matching circuit. The gain change does not need to be controlled through a digital circuit in a matched mode, automatic gain change adjustment is achieved only by conducting negative feedback through an analog circuit, the operation difficulty is low, and the automatically-adjusted variable gain amplification circuit can be widely applied to the technical field of integrated circuits.