Abstract: A power detector having a differential input unit and a differential output unit. In one aspect, the invention may be a power detector including a differential input unit including a differential input terminal to which an AC signal is input and a DC voltage generator which generates and outputs a DC voltage; and a differential output unit including a differential output terminal which full wave rectifies the AC signal input from the differential input unit and outputs a differential signal, wherein a negative output terminal of the differential output terminal is connected to the output terminal of the DC voltage generator.

Abstract: Disclosed is a self-correlation receiver of a transceiver in which a transmitter shares an antenna with a receiver. The self-correlation receiver includes: a clamper which receives a received signal, limits the magnitude of the received signal within a predetermined range and outputs a clamping signal; and a mixer which receives the received signal and the clamping signal and outputs a signal having a difference frequency between the received signal and the clamping signal.

Abstract: There is provided a dual band receiver receiving frequency signals in different bands, the receiver including: a first down converter converting a first band signal into a first intermediate frequency signal; a second down converter converting a second band signal into a second intermediate frequency signal; a first voltage control oscillator supplying a first oscillation frequency to the first down converter; a second voltage control oscillator supplying a second oscillation frequency to the second down converter; a first filter passing the first intermediate frequency signal within a desired bandwidth; a second filter passing the second intermediate frequency signal within a desired bandwidth; and a clock generator converting the first oscillation frequency of the first voltage control oscillator into sampling frequencies corresponding to integer multiples of first and second oscillation frequencies and supplying the sampling frequencies to first and second AD converters, respectively.

Abstract: There is provided an apparatus for duty cycle correction. The apparatus for duty cycle correction comprises a moving sum unit performing a moving sum calculation with respect to the square-wave signal and outputting the moving sum signal subjected to moving sum calculation, a comparison unit comparing the moving sum signal with a predetermined threshold voltage, outputting a high signal or low signal, a mean value calculation unit calculating the mean value of an output signal outputted from the comparison unit, the output signal being included in a section having a period integer times greater than that of the square-wave signal, and a threshold voltage control unit comparing the mean value with a middle value, increasing the threshold voltage when the mean value is greater than the middle value, and decreasing the threshold voltage when the mean value is less than the middle value.

Abstract: There is provided an apparatus for duty cycle correction. The apparatus for duty cycle correction comprises a moving sum unit performing a moving sum calculation with respect to the square-wave signal and outputting the moving sum signal subjected to moving sum calculation, a comparison unit comparing the moving sum signal with a predetermined threshold voltage, outputting a high signal or low signal, a mean value calculation unit calculating the mean value of an output signal outputted from the comparison unit, the output signal being included in a section having a period integer times greater than that of the square-wave signal, and a threshold voltage control unit comparing the mean value with a middle value, increasing the threshold voltage when the mean value is greater than the middle value, and decreasing the threshold voltage when the mean value is less than the middle value.

Abstract: There is provided a dual band receiver receiving frequency signals in different bands, the receiver including: a first down converter converting a first band signal into a first intermediate frequency signal; a second down converter converting a second band signal into a second intermediate frequency signal; a first voltage control oscillator supplying a first oscillation frequency to the first down converter; a second voltage control oscillator supplying a second oscillation frequency to the second down converter; a first filter passing the first intermediate frequency signal within a desired bandwidth; a second filter passing the second intermediate frequency signal within a desired bandwidth; and a clock generator converting the first oscillation frequency of the first voltage control oscillator into sampling frequencies corresponding to integer multiples of first and second oscillation frequencies and supplying the sampling frequencies to first and second AD converters, respectively.

Abstract: A sub-harmonic frequency conversion device includes: a voltage controlled oscillator for generating first to eighth oscillation frequency (LO) signals having a constant phase difference; a first mixer for performing a switching operation to mix the first to fourth LO signals having a phase difference of 90° and input signals, and outputting first IF signals; and a second mixer for performing a switching operation to mix the fifth to eighth LO signals having a phase difference of 90° and the input signals, and outputting second IF signals. Accordingly, the sub-harmonic frequency conversion device can use the low-frequency LO signal, and the power consumption can be reduced. In addition, because the mixers are implemented using a symmetric structure of the MOS transistors, the circuit configuration can be easily implemented.

Abstract: An air conditioning system including a compressor for compressing high temperature air supplied by an engine, a turbine for cooling the compressed air by expanding the compressed air, a condenser which is connected to the turbine and condenses air, and an axially hollow rotation shaft coaxially coupling the compressor and the turbine, the shaft allowing a portion of the high temperature air flowing in the compressor to pass through the shaft toward the turbine for mixing with the air cooled in the turbine and supplied to the condenser.