摘要:
A frequency calibration loop circuit having a pre-set frequency channel word (FCW) command value, a bit inputted to obtain a target frequency in an oscillator and a pre-set minimum division ratio n (n is a constant) of a programmable divider, includes: an oscillator adjusting an oscillation frequency of an oscillation signal according to a control value; a programmable divider dividing the oscillation signal according to a division ratio to output a divided signal; a counter counting the number of clocks of the divided signal for one cycle of a reference signal to output a count value; and a frequency detector obtaining the control value by subtracting the count value from a reference comparison value, wherein the reference comparison value is obtained by dividing a Frequency Channel Word (FCW) command value by a minimum division ratio of the programmable divider.
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:
There is provided a capacitor having variable capacitance, which forms different capacitances according to a control signal by applying a switch to a metal-oxide-metal (MOM) structure plate capacitor using a CMOS process. The capacitor includes a stack structure including a plurality of metal layers including a first metal layer, and a plurality of dielectric layers respectively interposed between the plurality of metal layers, and a switch part including at least one switch having one side connected to at least one metal layer among the plurality of metal layers other than the first metal layer. The first metal layer and the other side of the switch serve as both terminals of the capacitor, and at least two capacitances are provided between both terminals of the capacitor upon controlling a short/open of the switch.
摘要:
An automatically gain controllable linear differential amplifier using a variable degeneration resistor is disclosed. The linear differential amplifier includes an input end, a bias current source, a load unit, a first MOS transistor and a second MOS transistor. The linear differential amplifiers of the present invention can control an amplifying gain according to an input signal and improve linearity IIP3 without needing additional power consumption caused by improving the linearity. The automatically gain controllable linear differential amplifier uses NMOS/PMOS transistor so an integration process of the amplifier can be implemented more conveniently and efficiently.
摘要:
A direct conversion receiver includes: a high linearity mixer device including a sampler unit charge-sampling an input current according to a sampling frequency, and a buffer unit receiving an output signal from the sampler unit while having a low input impedance, amplifying the received signal, and outputting a current signal; and a filter device decimating an output signal from the mixer device and FIR-filtering the decimated signal.
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:
A frequency calibration loop circuit having a pre-set frequency channel word (FCW) command value, a bit inputted to obtain a target frequency in an oscillator and a pre-set minimum division ratio n (n is a constant) of a programmable divider, includes: an oscillator adjusting a oscillation frequency according to control value; a programmable divider dividing the oscillation frequency according to a division ratio; a counter counting the number of clocks of the divided frequency by using a reference frequency; and a frequency detector outputting a value obtained by subtracting the number of the counted clocks from a reference comparison value, a value obtained by dividing a Frequency Channel Word (FCW) command value by a minimum division ratio of the programmable divider, as the control value of the oscillator.
摘要:
In a digital receiver, a noise attenuation and signal magnitude mapping variable amplifying unit includes a filter and an amplifier, amplifies and band-bass filters an analog signal and attenuating white noise and an interference signal other than a band signal. An ADC performs subsampling on a carrier frequency of a desired signal and performs oversampling on the band of the desired signal by using a sampling frequency to convert the analog signal which has passed through the noise attenuation and signal magnitude mapping variable amplifying unit into a digital signal of a direct conversion frequency band or an intermediate frequency band. The ADC has a dynamic range for processing both the desired signal and an undesired signal adjacent to the desired signal. A digital signal processing unit converts a signal frequency of the digital signal or digital-filters an undesired signal within the digital signal and processes the digital signal by digitally adjusting a gain.
摘要:
The present invention relates to a single frequency synthesizer based FDD transceiver. A single frequency synthesizer generates and provides a carrier frequency so that frequency up-conversion and frequency down-conversion can be performed at the time of transmission and reception. Accordingly, the area, power consumption, and design complexity of the entire system can be reduced, and the performance of the system can be improved.