An integrated circuit having integrated inductors includes at least one pair of transistors, and at least one inductor group which includes a pair of inductors coupled to the at least one pair of the transistor, respectively. The pair of the inductors form a spiral shape on a plane and the inductors arranged symmetrically to each other. Magnetic fluxes, which are generated by current flows along the inductors of the at least one inductor group, are formed in a direction to mutually intensify the magnetic fluxes according to differential signals applied to the at least one transistors from outside. Accordingly, high inductance and high quality factor can be attained owing to the positive magnetic coupling of the inductors.
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.
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.
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.
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.