摘要:
An apparatus and method for self-calibrating mismatching orthogonal signals and non-linearity of a circuit occurring in a mobile transceiver. For this, in a mobile terminal, a transmitter is used as a signal generator and a receiver is used as a response characteristic measurer. A base band processor calibrates mismatching signals and non-linearity in a reception side and a transmission side, based on a test signal received via the transmitter and a test signal received via the receiver.
摘要:
An apparatus and method for compensating for the frequency offset of a received signal in a receiving apparatus of a mobile communication system. In the present invention, a sine component is calculated by adding I and Q channel signals resulting from downconverting a training sequence inserted between data symbols, and a cosine component is calculated by subtracting the Q channel signal from the I channel signal. Using the cosine and sine components at two time points, tangent components for the two time points are computed and thus first and second phase values are obtained. The frequency offset is estimated by determining the slope of a second-order line derived from the first and second phase values. The frequency offset of the received signal is compensated for based on the estimated frequency offset.
摘要:
A method of channel coding a digital communication system and a device using the same is provided. The method includes quantizing analog data to digital data, the digital data corresponding to a predetermined number of digital codes; allocating channel codes to the digital codes, as a Hamming distance between a pair of channel codes corresponding to any pair of the digital codes is proportional to a difference between analog values of the pair of the digital codes; and channel coding the digital data by using the channel codes which are allocated to the digital codes to generate channel coded digital data. Accordingly, digital data, such as multimedia digital data without source coding and the like, of which information significance is different may be effectively transmitted and received.
摘要:
A mixer circuit having improved linearity and noise figure is disclosed. The mixer circuit comprises an amplification unit having an input terminal and an output terminal, the amplification unit amplifying a signal applied to the input terminal to output it to the output terminal; a mixing unit having first, second and third input terminals, and first and second output terminals, the mixing unit mixing signals respectively applied to the first and second input terminals with a signal supplied to the third input terminal, to respectively output the mixed signals to the first and second output terminals; a capacitor connected between the output terminal of the amplification unit and the third input terminal of the mixing unit; and a current source for providing a specific quantity of current to the third input terminal of the mixing unit such that the quantity of current flowing through the third input terminal of the mixing unit is substantially larger than the quantity of current flowing through the amplification unit.
摘要:
A low noise amplifier includes an input matching means of an input stage and an output matching means of an output stage, a common source transistor and a common gate transistor serially connected between the input matching means and the output matching means, a first inductor connected between said common source transistor and common gate transistor a second inductor connected between the common point of said common source transistor and common gate transistor and the output stage of said common gate transistor. Therefore, the low noise amplifier allows the points of .GAMMA..sub.opt and G.sub.max to be closer to each other so that the noise and input gain simultaneous matching is performed, thereby improving the performance.
摘要:
The present invention relates to a high efficiency solar cell and a manufacturing method thereof. The high efficiency solar cell of the present invention comprises a lower solar cell layer comprising a single crystalline silicon-based pn thin film; an upper solar cell layer stacked on the upper portion of the lower solar cell layer and comprising an amorphous silicon-based pin thin film; and a glass substrate formed on the upper portion of the upper solar cell layer to receive sunlight. According to the present invention, it has an effect that a low-cost high efficiency solar cell can be manufactured.
摘要:
The present invention relates to a thin-film solar cell and a fabrication method thereof, the solar cell having a structure that a glass substrate, a transparent conductive oxide, a multi-junction solar cell layer and an electrode layer are stacked, wherein a first solar cell layer and a second solar cell layer, which are in a multi-junction, are electrically connected with each other in parallel, and one or more unit cells connected in parallel are grouped to be electrically connected with each other in series. According to the present invention, a thin-film solar cell having a unit cell in a structure that two solar cell layers having different characteristics are connected with each other in parallel, and having a structure that several unit cells are connected with each other in series, can achieve higher output and efficiency than a thin-film solar cell having a structure that several solar cell layers are connected in series.
摘要:
The present invention relates to a photovoltaic device through a lateral crystallization process and a fabrication method thereof, and in particular to a high efficiency solar cell module and a fabrication method thereof.The present invention comprises a first solar cell having an amorphous silicon layer formed on a first substrate, a second solar cell having a microcrystalline silicon semiconductor layer formed on a second substrate, and a junction layer junctioning the first solar cell and the second solar cell, making it possible to obtain a solar cell with high efficiency, low fabricating costs, high product characteristic, and high reliability.
摘要:
An apparatus and method for precisely measuring various biological information of a user's body by using a single measuring apparatus enable precisely and effectively measuring biological information including body fat, pulse and a blood vessel aging degree. By measuring an infrared absorbance or infrared rays irradiated to a measurement target according to a modulation and tuning method and obtaining the information with reference to supplementary biological information obtained from a user, the plurality of biological information can be precisely measured at a low driving voltage through the modulation and tuning method by using a single infrared light source. Also, the measuring apparatus can be reduced in size by simplifying its construction and can be effectively integrated into various device.
摘要:
A method for manufacturing a poly-crystal silicon photovoltaic device using horizontal metal induced crystallization comprises the steps of forming at least one layer of an amorphous silicon thin film on a substrate, forming at least one groove of which depth is less than or equal to that of the thin film on the amorphous silicon thin film, and horizontally crystallizing the amorphous silicon thin film by forming a metal layer on an upper portion of the groove. Since a crystal shape and a growth direction of the photovoltaic device can be adjusted by the method, a poly-crystal silicon thin film for improving current flow can be formed at a low-temperature.