摘要:
Provided is a mixer including: an amplifier amplifying an input signal using at least one amplifier element; a mixing unit mixing the input signal amplified by the amplifier with a local oscillator signal output from a local oscillator. The mixing unit includes at least one pair of switching elements switching the amplifier, and the switching elements are MOSFETs having gates and body nodes to which a same local oscillator signal is applied. Thus, a time required for turning on the switching elements can be reduced, and 1/f noise is also reduced. Also, an overdrive voltage can be increased with respect to local oscillator signals having an identical intensity. Thus, a relatively low voltage operation can be performed.
摘要:
Provided is a mixer including: an amplifier amplifying an input signal using at least one amplifier element; a mixing unit mixing the input signal amplified by the amplifier with a local oscillator signal output from a local oscillator. The mixing unit includes at least one pair of switching elements switching the amplifier, and the switching elements are MOSFETs having gates and body nodes to which a same local oscillator signal is applied. Thus, a time required for turning on the switching elements can be reduced, and 1/f noise is also reduced. Also, an overdrive voltage can be increased with respect to local oscillator signals having an identical intensity. Thus, a relatively low voltage operation can be performed.
摘要:
A buffer amplifier, which includes a first differential signal amplifier including first and second NMOSFETs (N-type metal-oxide semiconductor field-effect transistors) amplifying differential input signals; a second differential signal amplifier including first and second PMOSFETs (P-type metal-oxide semiconductor field-effect transistors) amplifying the differential input signals; a first feedback resistor including an end commonly connected to drains of the first NMOSFET and the first PMOSFET and the other end commonly connected to gates of the first NMOSFET and the first PMOSFET; a second feedback resistor including an end commonly connected to drains of the second NMOSFET and the second PMOSFET and the other end commonly connected to gates of the second NMOSFET and the second PMOSFET; and a current source providing a bias current for driving the first and second differential signal amplifiers, is provided.
摘要:
A radio frequency identification (RFID) reader is provided, having a transmitting circuit that generates a transmitted signal to operate an RFID tag, a receiving circuit that receives a received signal including a tag signal from the RFID tag and a transmission carrier leakage signal leaking from the transmitting circuit, and a leakage removing circuit that senses a phase and amplitude of the transmission carrier leakage signal inputted to the receiving circuit, converts the transmitted signal from the transmitting circuit into a signal having a phase opposite to that of the transmission carrier leakage signal and an amplitude equal to that of the transmission carrier leakage signal, and synthesizes the converted signal and the received signal inputted to the receiving circuit.
摘要:
A radio frequency identification (RFID) reader is provided, having a transmitting circuit that generates a transmitted signal to operate an RFID tag, a receiving circuit that receives a received signal including a tag signal from the RFID tag and a transmission carrier leakage signal leaking from the transmitting circuit, and a leakage removing circuit that senses a phase and amplitude of the transmission carrier leakage signal inputted to the receiving circuit, converts the transmitted signal from the transmitting circuit into a signal having a phase opposite to that of the transmission carrier leakage signal and an amplitude equal to that of the transmission carrier leakage signal, and synthesizes the converted signal and the received signal inputted to the receiving circuit.
摘要:
A buffer amplifier, which includes a first differential signal amplifier including first and second NMOSFETs (N-type metal-oxide semiconductor field-effect transistors) amplifying differential input signals; a second differential signal amplifier including first and second PMOSFETs (P-type metal-oxide semiconductor field-effect transistors) amplifying the differential input signals; a first feedback resistor including an end commonly connected to drains of the first NMOSFET and the first PMOSFET and the other end commonly connected to gates of the first NMOSFET and the first PMOSFET; a second feedback resistor including an end commonly connected to drains of the second NMOSFET and the second PMOSFET and the other end commonly connected to gates of the second NMOSFET and the second PMOSFET; and a current source providing a bias current for driving the first and second differential signal amplifiers, is provided.
摘要:
An inductor circuit includes a pair of inductors connected in parallel with each other and a switch for turning on and off electric power to one of the pair of inductors. The inductance of the inductor circuit can be varied and the quality factor Q can be improved. Further, RF circuits employing the inductor circuit can generate an intended operating frequency.
摘要:
Disclosed is a variable inductance applying device using a variable capacitor, and a variable frequency generating device thereof. The variable inductance applying device includes: a first inductor whose both terminals are connected to an inductance applying terminal applying inductance to an external circuit; a second inductor inductively coupled to the first inductor; and a variable capacitor connected to both terminals of the second inductor, which varies inductance from the inductance applying terminal by changing capacitance. Therefore, the inductance to be applied to the external circuit can be varied by changing the capacitance of the variable capacitor. Since the variable capacitor rarely contains a resistance component, energy loss due to the resistance component hardly occurs. As a result, the variable inductance applying device has a high value of Q.
摘要:
An inductor circuit includes a pair of inductors connected in parallel with each other and a switch for turning on and off electric power to one of the pair of inductors. The inductance of the inductor circuit can be varied and the quality factor Q can be improved. Further, RF circuits employing the inductor circuit can generate an intended operating frequency.
摘要:
A transmitter having a vertical BJT, capable of reducing power consumption, carrier leakage of a local oscillator and an error vector magnitude (EVM), is disclosed. In the transmitter, vertical BJTs implemented by a standard triplex well CMOS process are used in a frequency up-mixer and a baseband analog circuit including a DAC, an LPF, a VGA and a PGA, thereby improving the overall performance of the transmitter.