Abstract: A circuit for providing an output voltage substantially equal to a reference voltage includes: a low drop-out (LDO) regulator coupled to the reference voltage for producing the output voltage at an output terminal; a reference current source having a first end and a second end for providing a predetermined reference current; a first transistor having a first terminal coupled to a first supply voltage, a second terminal, and a control terminal coupled to the second terminal of the first transistor; a first switch for selectively coupling the second terminal of the first transistor to the first end of the reference current source according to a first control signal; and a second transistor having a first terminal coupled to the first supply voltage, a control terminal coupled to the control terminal of the first transistor, and a second terminal coupled to the output terminal.

Abstract: A dynamic current steering mixer. The dynamic current steering mixer comprises a Gilbert cell mixer core, a pair of load devices, a dynamic current steering cell, and a transconductor cell. The Gilbert cell mixer core has first and second nodes, receives a first differential input signal, and provides a differential output signal at the first nodes thereof. The load devices are respectively coupled between the first nodes of the Gilbert cell mixer core and a first fixed voltage. The dynamic current steering cell has third nodes coupled to the second nodes and fourth nodes. The transconductor cell is coupled between the fourth nodes and a second fixed voltage and receives a second differential input signal. The dynamic current steering cell alternately steers current of the transconductor cell to or away from the Gilbert cell mixer core.

Abstract: A frequency divider includes a plurality of logic circuit blocks. Each of the logic circuit blocks has a plurality of control terminals. At least one of the control terminals of one of the logic circuit blocks is arranged to receive an input clock signal having a first duty cycle. At least one of the remaining control terminals of the one of the logic circuit blocks is arranged to couple another one of the logic circuit blocks by a positive feedback. A clock signal at the at least one of the remaining control terminals has a second duty cycle different from the first duty cycle.

Abstract: A frequency-selective circuit includes a signal input port, a signal output port, and a frequency response control block. The frequency response control block includes a mixer module and a filter module. The mixer module has a first port electrically connected to a signal path between the signal input port and the signal output port, a second port electrically connected to the filter module, and a local oscillator (LO) port. The mixer module operates according to an LO input received by the LO port. The filter module is electrically connected to the second port of the mixer module.

Abstract: A method of setting filtering characteristic of a signal processing apparatus includes following steps: configuring a first signal processing path, included in the signal processing apparatus and electrically connected to a signal input port of the signal processing apparatus, to have a first filtering characteristic; and configuring a second signal processing path, included in the signal processing apparatus and electrically connected between the signal input port and the first signal processing path, to have a second filtering characteristic different from the first filtering characteristic. When an input signal received at the signal input port includes a first signal component with a first frequency and a second signal component with a second frequency, most of the first signal component is processed by the first signal processing path, and most of the second signal component is processed by the second signal processing path.

Abstract: A temperature compensated oscillation circuit capable of providing a stable frequency output over temperature is provided, in which an oscillator with a crystal resonator is arranged to generate an oscillation signal with an output frequency, and a temperature sensor provides a temperature compensation voltage of which a function is linear with respect to an ambient temperature of the oscillator. A first accumulation mode MOS varactor is coupled to the oscillator, and the first accumulation mode MOS varactor adjusts a capacitance thereof in response to the temperature compensation voltage, such that the coupled oscillator has a frequency compensation over temperature for the oscillation signal, wherein the frequency compensation substantially varies as an inverse function of a deviation of the crystal resonator over temperature when the ambient temperature is within a predetermined temperature range.

Abstract: A dynamic current steering mixer. The dynamic current steering mixer comprises a Gilbert cell mixer core, a pair of load devices, a dynamic current steering cell, and a transconductor cell. The Gilbert cell mixer core has first and second nodes, receives a first differential input signal, and provides a differential output signal at the first nodes thereof. The load devices are respectively coupled between the first nodes of the Gilbert cell mixer core and a first fixed voltage. The dynamic current steering cell has third nodes coupled to the second nodes and fourth nodes. The transconductor cell is coupled between the fourth nodes and a second fixed voltage and receives a second differential input signal. The dynamic current steering cell alternately steers current of the transconductor cell to or away from the Gilbert cell mixer core.

Abstract: A dynamic current steering mixer. The dynamic current steering mixer comprises a Gilbert cell mixer core, a pair of load devices, a dynamic current steering cell, and a transconductor cell. The Gilbert cell mixer core has first and second nodes, receives a first differential input signal, and provides a differential output signal at the first nodes thereof. The load devices are respectively coupled between the first nodes of the Gilbert cell mixer core and a first fixed voltage. The dynamic current steering cell has third nodes coupled to the second nodes and fourth nodes. The transconductor cell is coupled between the fourth nodes and a second fixed voltage and receives a second differential input signal. The dynamic current steering cell alternately steers current of the transconductor cell to or away from the Gilbert cell mixer core.

Abstract: A frequency divider has an inverting unit and a plurality of switch inverters in series. Each switch inverter comprises two inphase switches and is controlled by a clock. The two inphase switches of each switch inverter are respectively supplied by a first voltage and a second voltage, while any two switch inverters in series are respectively controlled by two inverted clocks. The two inphase switches are selectively turned on and off synchronously.

Abstract: A circuit for providing an output voltage substantially equal to a reference voltage includes: a low drop-out (LDO) regulator coupled to the reference voltage for producing the output voltage at an output terminal; a reference current source having a first end and a second end for providing a predetermined reference current; a first transistor having a first terminal coupled to a first supply voltage, a second terminal, and a control terminal coupled to the second terminal of the first transistor; a first switch for selectively coupling the second terminal of the first transistor to the first end of the reference current source according to a first control signal; and a second transistor having a first terminal coupled to the first supply voltage, a control terminal coupled to the control terminal of the first transistor, and a second terminal coupled to the output terminal.

Abstract: An integrated circuit for providing an output voltage substantially equal to a reference voltage includes: a low drop-out (LDO) regulator coupled to the reference voltage for producing the output voltage at an output terminal; a fast turn-on circuit coupled to the LDO regulator for quickly supplying an output current at the output terminal according to a first control signal; and a fast turn-off circuit coupled to the LDO regulator for quickly drawing a discharge current from the output terminal according to a second control signal.

Abstract: A reflection-type phase shifter is provided. The reflection-type phase shifter has a coupler, a first reflection load, and a second reflection load. The coupler has an input port for receiving an input signal and an isolated port for outputting an output signal due to a first reflected signal at a through port and a second reflected signal at a coupled port. The first reflection load reflects the first fraction of the input signal to thereby generate the first reflected signal. The second reflection load reflects the second fraction of the input signal to thereby generate the second reflected signal. In addition, at least one of the first and second reflection loads is equivalent to a transmission line.

Abstract: According to an embodiment of the present invention, an oscillating apparatus is provided. The oscillating apparatus generates an oscillating signal, and the oscillating apparatus includes a resonating device, a transconductive device, a biasing device, and a current compensating device. The resonating device generates the oscillating signal; the transconductive device is coupled to the resonating device for providing the resonating device with a positive feedback loop; the biasing device is coupled to the transconductive device for providing the transconductive device with a biasing current; and the current compensating device is coupled between the resonating device and the biasing device for providing the biasing device with a compensating current to compensate for a current reduction of the transconductive device.

Abstract: A radio frequency voltage controlled oscillator and method for designing it are provided. The RF VCO comprises a differential oscillator and a cascoded current source. The cascoded current source substantially provides a constant current bias to the differential oscillator. A first biased transistor in the cascoded current source is connected to the differential oscillator. A second biased transistor is cascoded to the first biased transistor. A low pass filter is cascoded between the first second biased transistors.

Abstract: A dynamic current steering mixer. The dynamic current steering mixer comprises a Gilbert cell mixer core, a pair of load devices, a dynamic current steering cell, and a transconductor cell. The Gilbert cell mixer core has first and second nodes, receives a first differential input signal, and provides a differential output signal at the first nodes thereof. The load devices are respectively coupled between the first nodes of the Gilbert cell mixer core and a first fixed voltage. The dynamic current steering cell has third nodes coupled to the second nodes and fourth nodes. The transconductor cell is coupled between the fourth nodes and a second fixed voltage and receives a second differential input signal. The dynamic current steering cell alternately steers current of the transconductor cell to or away from the Gilbert cell mixer core.

Abstract: A frequency divider has an inverting unit and a plurality of switch inverters in series. Each switch inverter comprises two inphase switches and is controlled by a clock. The two inphase switches of each switch inverter are respectively supplied by a first voltage and a second voltage, while any two switch inverters in series are respectively controlled by two inverted clocks. The two inphase switches are selectively turned on and off synchronously.

Abstract: A distributed amplifier is disclosed herein, which includes a signal amplification unit amplifying a RF input signal fed into the RF signal, a first biasing circuit providing a direct current (DC) bias signal, a second biasing circuit providing a DC bias signal, the variable terminal resistance providing an adjustable resistance, a RF signal input terminal provided for input of the RF input signal and a RF signal output terminal for output of a RF output signal. The output RF signal from the distributed amplifier is obtained from a gained version of the input RF signal. Since a load mismatch issue is compensated, a gain flatness issue is considerably improved and thus a gain-adjustable range is increased with respect to the distributed amplifier.

Abstract: An integrated circuit for providing an output voltage substantially equal to a reference voltage includes: a low drop-out (LDO) regulator coupled to the reference voltage for producing the output voltage at an output terminal; a fast turn-on circuit coupled to the LDO regulator for quickly supplying an output current at the output terminal according to a first control signal; and a fast turn-off circuit coupled to the LDO regulator for quickly drawing a discharge current from the output terminal according to a second control signal.

Abstract: A distributed amplifier is disclosed herein, which includes a signal amplification unit amplifying a RF input signal fed into the RF signal, a first biasing circuit providing a direct current (DC) bias signal, a second biasing circuit providing a DC bias signal, the variable terminal resistance providing an adjustable resistance, a RF signal input terminal provided for input of the RF input signal and a RF signal output terminal for output of a RF output signal. The output RF signal from the distributed amplifier is obtained from a gained version of the input RF signal. Since a load mismatch issue is compensated, a gain flatness issue is considerably improved and thus a gain-adjustable range is increased with respect to the distributed amplifier.