7results about How to "Improve modulation effect" patented technology

The present invention relates to a method based on D 2 Terahertz phased array device of NNs and implementation method thereof. The phased array device includes an active modulation layer and a two-layer metasurface layer structure. The active modulation layer mainly includes patterned micro-nano metal electrodes and active functional materials, and the optical properties of the active functional materials are adjusted by applying an external voltage, so as to achieve a beam output with a specific phase distribution in the terahertz band. The metasurface layer is composed of a silicon pillar structure array located on the surface of the substrate. The two metasurface layers can finely control the complex electric field distribution of a specific diffraction plane to construct an optical diffraction neural network architecture. For each required control mode, the phase distribution of the metasurface layer is optimized using the gradient descent and back propagation algorithms in the neural network, and active control of a specific beam direction can be achieved under different voltage drives. The present invention solves the problems of terahertz phased array technology in terms of control accuracy, continuity, etc., and provides a more efficient and flexible beam control method.

The invention relates to the technical field of coherent light communication, and provides a digital subcarrier multiplexing coherent light communication system and method, the system divides a single carrier signal into a plurality of subcarrier signals for respective modulation, and the system comprises a transmitting module, a channel unit and a receiving module; the transmitting module is used for modulating and transmitting a subcarrier multiplexing signal based on a DSP (Digital Signal Processor) algorithm, and comprises a wide-area complex recursive least square algorithm; the transmitting module performs hybrid modulation on the plurality of subcarrier signals; half of the subcarrier signals are configured with preposed pilots. According to the invention, based on the wide-area complex number recursive least square algorithm, the subcarrier signal is converted from a real number to a wide-area complex number, a significant modulation effect is still achieved under high-frequency attenuation, and the bit error rate performance is improved; the transmitting module performs hybrid modulation on a plurality of subcarrier signals, and configures different code rates of forward error correction codes according to the order of each subcarrier signal modulation format, so that the spectrum efficiency is improved; and only half of the subcarrier signals need to be configured with the preposed pilot frequency, so that the pilot frequency overhead is reduced.

The invention discloses an active frequency shift backscattering 2ASK modulation device, which comprises a receiving and transmitting common antenna, a signal directional transmission isolation module, a switch amplification modulation circuit and a control module, the control module is used for generating a 2ASK modulation signal and a frequency shift signal, the 2ASK modulation signal is output to a modulation signal input end of the line switching unit through a first control signal output end of the control module, and the frequency shift signal is output to a frequency shift signal input end of the line switching unit through a second control signal output end of the control module; under the action of two paths of signals output by the control module, the switch amplification modulation circuit modulates carrier signals received by the antenna, ASK signal modulation and frequency shifting are carried out firstly, useless frequency is filtered out through the filter, and the signals are amplified through the low-power-consumption amplifier and then transmitted to the antenna to be transmitted through the circulator. According to the method, the problem of self-interference of a traditional Backscatter ASK communication system during high-sensitivity receiving at the AP end is solved, and the good receiving effect of the AP end is guaranteed.

The invention belongs to the technical field of alternating current motors and driving control, discloses a three-phase series winding motor three-dimensional space vector modulation strategy and an overmodulation processing method, and aims to improve the control performance of a three-phase series winding motor and provide positive zero-sequence current suppression capability. The invention provides a three-phase series winding motor three-dimensional space vector modulation strategy based on a space slicing method and an overmodulation strategy thereof, a series winding motor three-dimensional linear modulation area is effectively expanded, a simple and effective basic voltage vector selection table is provided, and an accurate linear modulation area mathematical model is given. In addition, a corresponding three-dimensional overmodulation method is provided, and the control performance of the series winding motor in a linear modulation area and an overmodulation area is improved.

This invention discloses an optimization device and method for laser spot edge diffraction, relating to the field of optical instrument technology. The optimization device includes two sets of guiding mechanisms, two sets of driving mechanisms, and two sets of aperture pairs. Each aperture pair includes two opposing aperture plates, the edges of which are used to define the light transmission boundary and have a serrated structure. The driving mechanisms drive the two aperture plates in the same set to move synchronously in opposite directions along the guiding direction. The positions of the two aperture pairs are independently controlled to combine and form different light transmission boundaries. In the optimization method, the positions of the two aperture pairs are adjusted according to the edge morphology of the laser beam to be optimized, and the laser beam is made to pass through the target light transmission boundary for edge intensity modulation. Through the technical solution of this invention, the edge diffraction caused by traditional straight-edge apertures is reduced, and the edge smoothness of the laser beam, the flexibility of light transmission boundary adjustment, the adaptability to different spot morphologies, the shaping consistency, and the processing stability are improved.

The invention provides a metasurface design method and a metasurface, and the design method comprises the steps: selecting different incident angles, and carrying out the simulation test of the metasurface formed by the arrangement of superstructure units with different periodic values, thereby obtaining the efficiency of the metasurface formed by the arrangement of the superstructure units with different periodic values at the same incident angle; selecting the optimal metasurface efficiency of different incident angles to obtain period values corresponding to the different incident angles; superstructure units with corresponding periodic values are arranged in the metasurface areas corresponding to different incident angles; by selecting the optimal metasurface efficiency of different incident angles, period values corresponding to the different incident angles are determined, after the superstructure units of the corresponding period values are arranged in the metasurface area, a better modulation effect on large-angle incident light can be achieved, the metasurface modulation method is suitable for a large numerical aperture (NA) system and a wide-angle imaging scene, and the application range of the metasurface modulation method is widened. The efficiency of a large NA system or the wide-angle imaging quality can be improved.

The utility model provides a composite filter stick and a cigarette. The composite filter stick comprises a first filter stick section and a second filter stick section, the second filter stick section comprises a second base body and first functional material particles needed for modulating smoke, and the first functional material particles are distributed in the second base body; in the length direction of the composite filter stick, a gap is formed between the first filter stick section and the second filter stick section, and the third filter stick section comprises a first wrapping object wrapping the periphery of the gap and second functional material particles which are filled in the gap and needed for modulating smoke. The first filter stick section, the third filter stick section and the second filter stick section are sequentially arranged in the length direction of the composite filter stick. The cigarette comprises the composite filter stick. The composite filter stick and the cigarette provided by the utility model can improve the modulation effect of the functional material particles on smoke.