64results about How to "Change bandwidth" patented technology

The invention discloses a wide-stopband LTCC (low temperature co-fired ceramic) band-pass filter based on a magnetoelectric coupling counteraction technology. The wide-stopband LTCC band-pass filter based on the magnetoelectric coupling counteraction technology comprises two quarter-wave resonators, a metal floor and a pair of feed structures, wherein the resonators and feed patches are distributed on four conductor layers; the first layer is a feed layer with large feed patches and CPW (coplanar waveguide) feed ports; the two quarter-wave resonators are distributed at the second layer and the fourth layer, and the third layer is a grounding layer; the feed patches transmit energy to the resonators by means of broadside coupling; the resonators transmit energy to each other via side coupling, magnetic coupling and electric coupling exist between the two resonators simultaneously, the coupling in intervals close to a grounding end mainly is the magnetic coupling, and the coupling in intervals close to the open-circuit ends of the resonators mainly is the electric coupling; and the position of the transmission zero point of the filter can be conveniently adjusted by adjusting the intensities of the magnetic coupling and the electric coupling. The wide-stopband LTCC band-pass filter based on the magnetoelectric coupling counteraction technology disclosed by the invention is provided with a plurality of transmission zero points, as well as is excellent in selectivity and stopband suppression performance, and compact in structure.

The invention discloses a current feedback operational amplifier circuit comprising a power supply, a bias current supply unit, a first common base-common emitter current mirror, a second common base-common emitter current mirror, a static bias circuit, an input buffer stage, a voltage conversion stage and a drive output unit, wherein the drive output unit comprises a bias voltage circuit and an output buffer stage; the bias current supply unit is respectively connected with the input buffer stage through the first common base-common emitter current mirror and the second common base-common emitter current mirror and used for supplying bias current; and the static bias circuit is respectively connected with the inverted input end of the input buffer stage and the voltage conversion stage and used for stabilizing a static working point of the inverted input end. The current feedback operational amplifier circuit has the advantages of lower offset voltage, stronger on-load capacity and higher conversion rate and is beneficial to improvement of the precision and the linearity of the entire operational amplifier.

The invention discloses a numerical control LC voltage controlled oscillator with amplitude detection. The numerical control LC voltage controlled oscillator comprises an LC oscillator and an oscillation signal amplitude detection unit. The LC oscillator is composed of an LC frequency resonant unit, a capacitor array unit and a varactor array unit; and an output amplitude detection unit is composed of a differential amplification circuit with a tail current source and a transmission gate with a switch controller. The LC voltage controlled oscillator generates a high-performance and low-noise differential oscillation signal, and changes the bandwidth and the voltage control gain through a numerical control signal provided by an external circuit. The output amplitude detection unit receives an oscillated high-frequency differential signal and outputs the maximum value of the differential signal, and the amplitude of an oscillation signal can be obtained by subtracting a DC offset from the maximum value. The numerical control LC voltage controlled oscillator disclosed by the invention can not only realize a large variable capacitance range and a highly linear voltage control gain, and can further judge whether the circuit can perform normal oscillation work, obtain the amplitude of the high-frequency oscillation signal, and solve the problem of monitoring the oscillation circuit and the oscillation signal in real time.

A charge pump circuit includes a switching circuit for providing a charge and discharge current, and a control circuit for controlling the switching circuit. The switching circuit includes a first switch for controlling the charging speed. The control circuit generates a signal for controlling the first switch based on the pulse width of the input signal. The charge pump circuit of the present invention quickens the locking time of the phase locked loop.

A process based on single-mode transmitting optical fibre for preparing the optical fibre to implement different performance of acousto-optic filter includes using a commercially available optical fibre for transmission purpose, determining needed external diameter and etching speed, and etching the optical fibre by controlling etch time to change its refractivity in acousto-optical action region. Its advantages are simple process, easy control, high effect, no damage to core of optical fibre, and low loss of optical fibre.

The invention discloses an N-order acoustic meta-material low-frequency sound insulation structure, which relates to the technical field of mechanical noise and environmental noise control. The N-order acoustic meta-material low-frequency sound insulation structure comprises a plurality of (N-1)-order acoustic meta-material low-frequency sound insulation structures extending in an array mode in xand y directions, N-order mass blocks adhered to the centers of the (N-1)-order acoustic meta-material low-frequency sound insulation structures, and an external supporting frame, wherein N>=2; when Nis equal to 2, the second-order acoustic meta-material low-frequency sound insulation structure comprises a plurality of acoustic meta-material unit cells extending in an array mode in the x direction and the y direction and the second-order mass blocks attached to the center of the extending structures; and a sound insulation peak generated by the N-order acoustic meta-material low-frequency sound insulation structures is generated by a modal coupling anti-resonance effect of acoustic meta-materials of adjacent orders, and the N-order mass block is used for enhancing the modal coupling anti-resonance effect. The N-order acoustic meta-material low-frequency sound insulation structure has the advantages of being simple in structure, easy to adjust and the like, meanwhile, the structure haslarge expansion space, and potential application prospects are achieved for multi-frequency sound insulation within the low-frequency range.

A variable resonator includes a ring-shaped conductor line (2) which is provided on a dielectric substrate (5) and has a circumferential length of a wavelength at a resonance frequency or an integral multiple of the wavelength, and at least two circuit switches (31, 32), wherein the circuit switches (31, 32) have one ends (31) electrically connected to the ring-shaped conductor line (2) and the other ends (32) electrically connected to a ground conductor (4) formed on the dielectric substrate (5), electrical connection / disconnection between the ground conductor (4) and ring-shaped conductor line (2) can be switched, and the one ends (31) of the circuit switches (31, 32) are connected to the ring-shaped conductor line (2) on different portions.

A charge pump circuit includes a switching circuit for providing a charge and discharge current, and a control circuit for controlling the switching circuit. The switching circuit includes a first switch for controlling the charging speed. The control circuit generates a signal for controlling the first switch based on the pulse width of the input signal. The charge pump circuit of the present invention quickens the locking time of the phase locked loop.

The present disclosure provides a low band dipole and a multi-band multi-port antenna arrangement, wherein the low band dipole has four dipole arms, and the four dipole arms are horizontally and mutually perpendicularly placed in a “+” shape and adjacent two mutually perpendicular dipole arms are fed therebetween. The antenna arrangement includes a main reflector, at least one column of low band dipole array disposed on the main reflector, and at least one column of high band dipole array adjacent to the at least one column of the low band dipole array, wherein at least one low band dipole in each column of the at least one column of low band dipole array satisfies the following condition: the low band dipole has four dipole arms, and the four dipole arms are horizontally and mutually perpendicularly placed in a “+” shape, and adjacent two mutually perpendicular dipole arms are fed therebetween to form a + / −45 degree polarization. The multi-band multi-port antenna arrangement solves the problem that the high and low band dipole arms shield each other and reduces the mutual coupling between the high and low band dipoles by adopting the above-mentioned structure of the low band dipole.

Disclosed is an optical transceiver. The optical transceiver includes a decoder for decoding an 8B10B line-coded signal; a data mapper for separating the decoded signal into block units and securing extra memory capacity by mapping a data code and a block information code onto each of the separated blocks; and an FEC encoding unit for creating a Forward Error Correction (FEC) data and mapping the FEC data onto the extra memory capacity.

A variable resonator includes a first transmission line 101, a second transmission line 102 and a plurality of switch circuits 150. The electrical length of the first transmission line 101 is equal to the electrical length of the second transmission line 102. The characteristic impedance for the even mode of the first transmission line 101 is equal to the characteristic impedance for the even mode of the second transmission line 102. The characteristic impedance for the odd mode of the first transmission line 101 is equal to the characteristic impedance for the odd mode of the second transmission line 102. Each switch circuit 150 is connected to any of the first transmission line 101 and the second transmission line 102, and one of the switch circuits 150 is turned on.

The invention relates to a parametric amplification or parametric conversion system of an adjustable broadband laser pulse of a spectral response curve, which belongs to the field of nonlinear intense laser. The parametric amplification or parametric conversion system comprises a spatial frequency chirp transformation device, a splitting, attenuation and optical delay device, a partially reflecting mirror, a focusing cylindrical lens, a fan-shaped periodically poled crystal, a filtering device and a collimating cylindrical lens, wherein the partially reflecting mirror, the focusing cylindrical lens, the fan-shaped periodically poled crystal, the filtering device and the collimating cylindrical lens are arranged on an optical axial line in sequence, the output pump pulse of the splitting, attenuation and optical delay device enters the partially reflecting mirror from a 45-degree angle, and the installation directions of the partially reflecting mirror and the filtering device respectively form a 45-degree included angle with the output optical shaft of the spatial frequency chirp transformation device. The system of the invention not only can realize the parametric amplification or conversion for almost identical gains of all frequency components within the input signal bandwidth, but also can adjust the intensity and the position of each pump pulse according to needs, so as to change the bandwidth or the spectral property of the frequency response curve or the output pulse bandwidth. Moreover, the system has the advantages of simple structure, convenient calibration, flexible crystal selection and the like.