Abstract: The present invention relates to a direct current (DC) offset suppression circuit to suppress DC offsets occurring when a communication circuit where a complex filter is adopted performs self-mixing. The DC offset is suppressed by a DC feedback circuit adopted by a filter which is substituted for a complex filter in the communication circuit. But, the DC offset cannot be suppressed when a complex filter is used in the communication circuit. It is because phase changes of the complex filter cause output signal fed back to the input of the complex filter to generate phase differences. The present invention includes a phase compensation unit and a DC feedback unit. The phase compensation unit compensates a change in frequency between input and output of the complex filter for phase compensation. The DC feedback unit inverses and feeds back the compensated phase to an input of the complex filter.

Abstract: A low noise reference voltage circuit without using an amplifier inside is capable of transforming a current IPTAT in positive proportion to absolute temperature into a voltage VPTAT in positive proportion to absolute temperature, and outputting it to a ring oscillator. The low noise reference voltage circuit improves a degradation of noise performance compared with a conventional band-gap reference voltage circuit and is in characteristic of low noise and higher PSRR.

Abstract: The present invention provides a receiver with low power consumption. The receiver with low power consumption adjusts the gain of the programmable gain amplifier based on the automatic gain controller and further optimizes the gain bandwidth product by current-adjusting unit. The current-adjusting unit thus adjusts the current provided for the programmable gain amplifier, e.g. operational amplifier. Therefore, the gain bandwidth product of the programmable gain amplifier is optimized and the power consumption of the receiver is effectively decreased.

Abstract: The present invention provides a receiver having low power consumption and method thereof. The receiver with low power consumption adjusts the gain based on the automatic gain control information. The receiver acquires the signal peaks both after and before a channel selection filter and further analyzes the wanted signal and interference signal with respect to the signal peaks. The receiver determines the magnitude of the wanted signal and determines whether the interference signal exists. The receiver provides the signals with optimal current correspondingly in order to effectively decrease the power consumption of the receiver.

Abstract: The present invention relates to a direct current (DC) offset suppression circuit to suppress DC offsets occurring when a communication circuit where a complex filter is adopted performs self-mixing. The DC offset is suppressed by a DC feedback circuit adopted by a filter which is substituted for a complex filter in the communication circuit. But, the DC offset cannot be suppressed when a complex filter is used in the communication circuit. It is because phase changes of the complex filter cause output signal fed back to the input of the complex filter to generate phase differences. The present invention includes a phase compensation unit and a DC feedback unit. The phase compensation unit compensates a change in frequency between input and output of the complex filter for phase compensation. The DC feedback unit inverses and feeds back the compensated phase to an input of the complex filter.

Abstract: The present invention discloses a mixer circuit for mixing two input signals by source-coupled MOS transistors and outputting a mixed result. A duty cycle controlling MOS transistor is connected to a source of each source-coupled MOS transistor in series. A duty cycle controlling pulse is applied to a gate of the duty cycle controlling MOS transistor. The duty cycle controlling pulse has a phase shift of ?90 degrees with respect to a controlling pulse applied to the gate of the source-coupled MOS transistor connected with the duty cycle controlling MOS transistor in series. An AND-combination of the duty cycles of the two controlling pulses applied to the gates of the two MOS transistors connected in series can be controlled at 25%. Comparing to the conventional mixer circuit having a switch control duty cycle of 50%, the present invention achieves the effects of increasing the gain and reducing the noise figure.

Abstract: Provided is a receiver capable of automatically controlling a gain of the receiver and receiving three or more band signals. A gain controlled receiver includes a low noise amplifier, a first variable gain control amplifier, a frequency mixer, a filter, a second variable gain control amplifier, and a gain control block. The gain controlled receiver automatically controls gains of the low noise amplifier, the first variable gain control amplifier, the frequency mixer, the filter, the second variable gain control amplifier by detecting strength of the signals processed in the receiver. Therefore, without an additional manual tuning operation, the gain of the receiver can be automatically maintained in an optimal state. A multi-band processing receiver includes a first receiving unit, a second receiving unit, and a switch. The multi-band processing receiver can process three or more RF signals in multi-band by using a single receiver.

Abstract: A low noise reference voltage circuit without using an amplifier inside is capable of transforming a current IPTAT in positive proportion to absolute temperature into a voltage VPTAT in positive proportion to absolute temperature, and outputting it to a ring oscillator. The low noise reference voltage circuit improves a degradation of noise performance compared with a conventional band-gap reference voltage circuit and is in characteristic of low noise and higher PSRR.

Abstract: A variable-gain low-noise amplifier is provided. The variable-gain low-noise amplifier includes a first load, a second load, an input transistor, a pole/zero control circuit, and a gain control circuit. A first terminal of the first load is connected to a power-source voltage, and a second terminal thereof is connected to an output terminal. The second load is operated in response to a bias voltage, and a first terminal thereof is connected to the output terminal. A first terminal of the input transistor is connected to the second terminal of the second load, and a gate thereof is connected to an input terminal. The pole/zero control circuit adjusts frequency characteristics and a gain in response to at least one pole/zero control signal. A first terminal of the pole/zero control circuit is connected to the input terminal, and a second terminal thereof is connected to the output terminal. The gain control circuit adjusts the gain in response to at least one gain control signal.

Abstract: An attenuator for attenuating an input signal at a predetermined rate and a step attenuation device having the same are provided. The attenuator includes first to sixth impedance components. A terminal of the first impedance component is connected to an input signal. A terminal of the second impedance component is connected to the other terminal of the first impedance component. The other terminal of the second impedance component outputs an attenuated signal. A terminal of the third impedance component is connected to a common terminal of the first and second impedance components. A terminal of the fourth impedance component is connected to a ground voltage. A terminal of the fifth impedance component is connected to the other terminal of the fourth impedance component. The other terminal of the fifth impedance component is connected to the ground voltage. A terminal of the sixth impedance component is connected to a common terminal of the fourth and fifth impedance component.

Abstract: The present invention provides a receiver having low power consumption and method thereof. The receiver with low power consumption adjusts the gain based on the automatic gain control information. The receiver acquires the signal peaks both after and before a channel selection filter and further analyzes the wanted signal and interference signal with respect to the signal peaks. The receiver determines the magnitude of the wanted signal and determines whether the interference signal exists. The receiver provides the signals with optimal current correspondingly in order to effectively decrease the power consumption of the receiver.

Abstract: The present invention provides a receiver with low power consumption. The receiver with low power consumption adjusts the gain of the programmable gain amplifier based on the automatic gain controller and further optimizes the gain bandwidth product by current-adjusting unit. The current-adjusting unit thus adjusts the current provided for the programmable gain amplifier, e.g. operational amplifier. Therefore, the gain bandwidth product of the programmable gain amplifier is optimized and the power consumption of the receiver is effectively decreased.

Abstract: Provided is a low-power variable gain amplifier having a direct-current (DC) bias stabilizer.

Abstract: A variable-gain low-noise amplifier is provided. The variable-gain low-noise amplifier includes a first load, a second load, an input transistor, a pole/zero control circuit, and a gain control circuit. A first terminal of the first load is connected to a power-source voltage, and a second terminal thereof is connected to an output terminal. The second load is operated in response to a bias voltage, and a first terminal thereof is connected to the output terminal. A first terminal of the input transistor is connected to the second terminal of the second load, and a gate thereof is connected to an input terminal. The pole/zero control circuit adjusts frequency characteristics and a gain in response to at least one pole/zero control signal. A first terminal of the pole/zero control circuit is connected to the input terminal, and a second terminal thereof is connected to the output terminal. The gain control circuit adjusts the gain in response to at least one gain control signal.

Abstract: An attenuator for attenuating an input signal at a predetermined rate and a step attenuation device having the same are provided. The attenuator includes first to sixth impedance components. A terminal of the first impedance component is connected to an input signal. A terminal of the second impedance component is connected to the other terminal of the first impedance component. The other terminal of the second impedance component outputs an attenuated signal. A terminal of the third impedance component is connected to a common terminal of the first and second impedance components. A terminal of the fourth impedance component is connected to a ground voltage. A terminal of the fifth impedance component is connected to the other terminal of the fourth impedance component. The other terminal of the fifth impedance component is connected to the ground voltage. A terminal of the sixth impedance component is connected to a common terminal of the fourth and fifth impedance component.

Abstract: Provided is a low-power variable gain amplifier having a direct-current (DC) bias stabilizer.

Abstract: Provided is a receiver capable of automatically controlling a gain of the receiver and receiving three or more band signals. A gain controlled receiver includes a low noise amplifier, a first variable gain control amplifier, a frequency mixer, a filter, a second variable gain control amplifier, and a gain control block. The gain controlled receiver automatically controls gains of the low noise amplifier, the first variable gain control amplifier, the frequency mixer, the filter, the second variable gain control amplifier by detecting strength of the signals processed in the receiver. Therefore, without an additional manual tuning operation, the gain of the receiver can be automatically maintained in an optimal state. A multi-band processing receiver includes a first receiving unit, a second receiving unit, and a switch. The multi-band processing receiver can process three or more RF signals in multi-band by using a single receiver.

Abstract: A binary coding method of a fingerprint image, the method comprises detecting a ridge range direction and a ridge curvature of the fingerprint image; and binary coding the fingerprint image using a binary coding filter selected in accordance with the ridge curvature.

Abstract: There is an ion mobility spectrometer(IMS) comprising a ion drift tube comprising a reaction region, a shutter grid, a drift region and a collector; an inlet for introducing a carrier gas into the reaction region; and an ionization source in the reaction region, wherein flexible PCBs (printed circuit board) are fixed onto the surface of the ion drift tube to develop electric fields along the axis of the reaction region and the drift region for the movement of ions generated in the reaction region to the collector.