Abstract: The present invention belongs to the technical field of biomass carbon materials, and relates to a lignin porous carbon nanosheet, a preparation method therefor, and an application thereof in supercapacitor electrode materials. The method of the present invention performs layer-by-layer self-assembly of sulfonated lignin and oxalate in a selective solvent to prepare a layer-by-layer self-assembled lignin/oxalate composite, which is then carbonized and pickled to obtain the lignin porous carbon nanosheets. The lignin porous carbon nanosheets prepared by the above method of the present invention have a specific surface area of 200-1500 m2/g, a micropore specific surface area of 100-500 m2/g, a mesoporous specific surface area of 100-1000 m2/g, a pore diameter of 0.5-30 nm, and a pore volume of 0.5-1.5 cm3/g; they can be applied to supercapacitor electrode materials, showing higher specific capacitance and excellent rate performance (with a specific capacitance retention rate of 76.

Abstract: The present disclosure provides a flexible solar cell and a manufacturing method thereof. The manufacturing method includes disposing a flexible substrate on a back electrode to transfer to the solar cell unit and the flexible substrate onto a temporary substrate, and then separating the temporary substrate from the flexible substrate after the flexible solar cell is manufactured. Thus, it reduces tedious bonding and de-bonding operations in manufacturing process of the flexible solar cell, can improve production efficiency, and avoids damage of cells by a high-temperature condition required for bonding. Also, the process is quick and not easy to damage the solar cell. The front electrode, back electrode and flexible substrate in the flexible solar cell all can be prepared by plating, with a relatively low cost and low requirement for equipment, which is conductive to mass production in industry.

Abstract: The invention relates to a method and circuit for linearizing amplifiers and other nonlinear circuits for multi-carrier signals. An output signal from the amplifier is sampled, and a correlation matrix of size N×N is computed from the sampled signal, wherein N exceeds the number of multiplexed carriers in the signal. A signal-to-distortion ratio (SDR) is then estimated based on a ratio of one or more largest to one or more smallest eigenvalues of the correlation matrix, and the signal into the amplifier is pre-distorted so as to maximize the SDR.

Abstract: The invention relates to a method and circuit for linearizing amplifiers and other nonlinear circuits for multi-carrier signals. An output signal from the amplifier is sampled, and a correlation matrix of size N×N is computed from the sampled signal, wherein N exceeds the number of multiplexed carriers in the signal. A signal-to-distortion ratio (SDR) is then estimated based on a ratio of one or more largest to one or more smallest eigenvalues of the correlation matrix, and the signal into the amplifier is pre-distorted so as to maximize the SDR.

Abstract: The invention provides a type-based method to compensate for distortions in circuits operating on a plurality of input modulated signals to form one or more output modulated signals. Steps of the method include low-rate sampling of the output signal to obtain a statistical characteristics thereof, and adjusting parameters of the circuit to introduce a controlled degree of cross-coupling between the signals until the statistical characteristics of the output signal approximates a reference characteristics defined by the used modulation formats. Another aspect of the invention provides a self-calibrating multi-port circuit implementing the method.

Abstract: The invention relates to methods and circuits for compensating linear in-band distortions such as those occurring in RF circuits of broad band communication systems. A low-rate sampling is used to collect statistical information about a modulated signal after it passed through the distorting circuits, which is then compared to reference statistical information for the modulated signal to iteratively adjust a frequency response of an equalizing linear filter inserted into the signal path so as to compensate for the distortions.

Abstract: The invention relates to methods and circuits for compensating linear in-band distortions such as those occurring in RF circuits of broad band communication systems. A low-rate sampling is used to collect statistical information about a modulated signal after it passed through the distorting circuits, which is then compared to reference statistical information for the modulated signal to iteratively adjust a frequency response of an equalizing linear filter inserted into the signal path so as to compensate for the distortions.

Abstract: The invention provides a type-based method to compensate for distortions in circuits operating on a plurality of input modulated signals to form one or more output modulated signals. Steps of the method include low-rate sampling of the output signal to obtain a statistical characteristics thereof, and adjusting parameters of the circuit to introduce a controlled degree of cross-coupling between the signals until the statistical characteristics of the output signal approximates a reference characteristics defined by the used modulation formats. Another aspect of the invention provides a self-calibrating multi-port circuit implementing said method.

Abstract: This invention is about a novel estimation technique for generating a predistortion function to compensate for the AM-AM and AM-PM non-linear conversion distortions of non-linear power amplifiers or non-linear circuits. Based on the cumulative type of power amplifier output envelope, a non-parametric baseband predistortion function is derived. The non-parametric approach avoids any model mismatch. In addition, the technique does not need to demodulate the input signal.

Abstract: A method for self-calibrating a vector modulator is disclosed, including the step of pre-distortion coefficients in dependence upon an in-phase signal, a quadrature signal, and an output envelope of an RF signal, and further comprising the steps of transforming a value representative of an output envelope represented in a nonlinear domain into a value representative of the output envelope represented in a linear domain, determining a parameter vector x as a solution of a linear equation within the linear domain, and determining the pre-distortion coefficients from the parameter vector x.

Abstract: This invention is about a novel estimation technique for generating a predistortion function to compensate for the AM-AM and AM-PM non-linear conversion distortions of non-linear power amplifiers or non-linear circuits. Based on the cumulative type of power amplifier output envelope, a non-parametric baseband predistortion function is derived. The non-parametric approach avoids any model mismatch. In addition, the technique does not need to demodulate the input signal.

Abstract: A method for self-calibrating a vector modulator is disclosed, including the step of pre-distortion coefficients in dependence upon an in-phase signal, a quadrature signal, and an output envelope of an RF signal, and further comprising the steps of transforming a value representative of an output envelope represented in a nonlinear domain into a value representative of the output envelope represented in a linear domain, determining a parameter vector x as a solution of a linear equation within the linear domain, and determining the pre-distortion coefficients from the parameter vector x.

Abstract: The present invention relates to the regeneration of in-phase (I) and quadrature (Q) signals in electronic devices commonly used in communication, radar and instrumentation electronics. The original signal of interest comprises two orthogonal components that are mathematically modelled using complex values, which are then decomposed into a real (I) and an imaginary (Q) component. These two components are orthogonal to each other and represent fully the signal of interest. The present method adaptively compensates for the gain and phase imbalances and DC offsets in I and Q signal regeneration. First, 3 phase shifted versions of the received signal, either down-converted to some intermediate frequency (IF) or at baseband, are digitized. Although the optimum phase shift between each version is 360°/3, any phase shift different than 0° and 180° is acceptable and no a priori knowledge of the phase shifts is required.