摘要:
Disclosed are an optical film and a preparation method thereof. The optical film comprises a base layer, a plurality of polymer particles disposed in the base layer, and voids formed in the base layer and enclosing the respective polymer particles, wherein the polymer particles comprise a crosslinked polymer. The optical film has uniform voids, enhanced processing and dimensional stabilities, as well as improved optical properties such as whiteness, hiding power, reflectance and the like. Thus, the optical film can be useful for a reflector sheet for a BLU of an LCD device, and the like.
摘要:
A pulse radar receiver includes a power splitter configured to split a transmit (TX) trigger signal for generating a TX pulse, a phase-locked loop (PLL) configured to receive a division ratio and the TX trigger signal split by the power splitter, and generate a sampling frequency, and a sampler configured to sample a reflected wave received through an RX antenna, according to the sampling frequency generated by the PLL. Accordingly, it is possible to provide a high distance resolution by generating a sampling frequency with a difference from a TX pulse to sample a reflected wave received through an RX antenna. Thus, it is possible to overcome a limitation in the distance resolution due to the pulse width and to measure a minute movement at a short distance. Therefore, the pulse radar receiver is applicable to high range resolution radar applications such as a living body measuring radar.
摘要:
A digital RF converter, a digital RF modulator, and a transmitter are provided. The digital RF converter includes a delta-sigma modulated bits (DSMB) sub-block that generates a current magnitude corresponding to least-significant n bits among input signals at a first sampling speed, a least-significant bit (LSB) sub-block that generates a current magnitude corresponding to intermediate k bits among the input signals at a second sampling speed lower than the first sampling speed, and a most-significant bit (MSB) sub block that generates a current magnitude corresponding to most-significant m bits among the inputs signals at the second sampling speed.
摘要:
Disclosed is a fractional digital phase locked loop with an analog phase error compensator. The digital phase locked loop with an analog phase error compensator can reduce excessive power consumption and power noise and transient current noise while increasing phase error detection resolution by performing fractional phase error detection and compensation through the analog phase error compensator.
摘要:
An all digital phase-locked loop (ADPLL) includes: a phase counter accumulating a frequency setting word value and the phase of a digitally controlled oscillator (DCO) clock and detecting a fine phase difference between a reference clock and a retimed clock; a phase detector detecting a digital phase error value compensating for a phase difference between the frequency setting word value and the DCO clock according to the fine phase difference to detect a digital phase error value; a digital loop filter filtering the digital phase error value and controlling PLL operational characteristics; a lock detector generating a lock indication signal according an output of the digital loop filter; a digitally controlled oscillator varying the frequency of the DCO clock according to the output from the digital loop filter; and a retimed clock generator generating the retimed clock by retiming the DCO clock at a low frequency.
摘要:
There is provided a digital lock detector and a frequency synthesizer using the same. The digital lock detector includes a comparator unit receiving a plurality of control bits, and generating a bit signal to notice a lock condition of the plurality of control bits; a delay cell block generating a plurality of delay signals based on the bit signal, and outputting a clock signal by combining the bit signal and the plurality of delay signals; and a detection unit detecting a shift time of the clock signal, and generating a lock indication signal according to the detection result.
摘要:
There is provided a digital lock detector and a frequency synthesizer using the same. The digital lock detector includes a comparator unit receiving a plurality of control bits, and generating a bit signal to notice a lock condition of the plurality of control bits; a delay cell block generating a plurality of delay signals based on the bit signal, and outputting a clock signal by combining the bit signal and the plurality of delay signals; and a detection unit detecting a shift time of the clock signal, and generating a lock indication signal according to the detection result.
摘要:
The present invention relates to a ROM division method for reducing the size of a ROM in a direct digital frequency synthesizer (DDFS), which is used to synthesize a frequency in a communication system requiring fast frequency conversion. A ROM consuming most energy in the system, a modified Nicholas architecture is brought forth to reduce the size of ROM. In this modified Nicholas architecture, a ROM is divided into coarse ROM and fine ROM to convert phase to sine value. The present invention divides the coarse ROM and the fine ROM into quantized ROM and error ROM respectively. Then, value stored in each ROM is segmented in certain intervals and the minimum quantized value in each of the section is stored in the quantized ROM, while the difference between the original ROM value and the quantized ROM value is stored in the error ROM. This way, the size of a ROM can be reduced. Phase value inputted in a DDFS, a sine value is calculated by adding the four ROM values, i.e., coarse-quantized ROM, coarse-error ROM, fine-quantized ROM and fine-error ROM.
摘要:
A frame synchronizing device for discriminating a time slot location for each channel of time-division multiplexed signals is disclosed. The frame synchronizing device according to the invention processes time-division multiplexed signals in parallel in a STM-4C(Synchronous Transport Module-4 Concatenation) of the Broadband Integrated Service Digital Network according to the ITU-T recommendation, such that the searching of frame synchronization can be achieved by detecting frame bytes on data being received at a high speed in the STM-4C structure to align the bytes based on the detected time interval, converting the frame data into the 8-bits parallel data and then detecting, in sequence, the frame bytes at a lower speed clock being divided by 8, thereby providing a simplified, less power consumptive frame synchronizing device in the STM-4C structure according to the ITU-T recommendation.
摘要:
Provided is an apparatus for automatic gain control (AGC) widely used in a receiver of a wireless communication system. The receiver of a wireless communication system includes: a step variable gain amplifier and an analog variable gain amplifier disposed in the path of a wireless signal and amplifying the wireless signal; an analog gain control unit for generating a gain control voltage for feedback-controlling an amplification value of the analog variable gain amplifier; a digital gain control unit for receiving the control voltage and generating a digital code determining an amplification value of the step variable gain amplifier. The apparatus for AGC constituted as described above can reduce power consumption and the number of devices by efficiently running an AGC loop in an analog domain, and can be embodied at low cost in a structure appropriately controlling the step gain amplifier and the analog gain amplifier.