The method for calibrating the frequency synthesiser using two-point FSK modulation consists, in a first phase, in supplying an excitation signal generated by a calibration unit to a sigma-delta modulator by deactivating a digital-to-analogue converter and transmitting the output signal from a loop filter of the synthesiser to the calibration unit, which digitally converts the incoming signal and offsets the phase shift between the excitation signal and the loop filter output signal in the calibration unit. In a second phase, the excitation signal is supplied to the sigma-delta modulator and to the activated digital-to-analogue converter, and the digital-to-analogue converter gain is calibrated by checking, in the calibration unit, the polarity of the loop filter output signal with respect to the excitation signal, and using a dichotomy algorithm.

According to one embodiment, an amplification circuit includes an amplifier having a gain based on a gain control signal and amplifying an input signal by the gain, and a control portion outputting the gain control signal for increasing the gain after decreasing the gain based on an amplitude of the input signal, when the amplitude of the input signal is detected.

Disclosed is a power amplification module which has a comparatively small size and is capable of adjusting the rising characteristic of a gain. The power amplification module includes a first gain control current generation circuit which generates a first gain control current changing with a control voltage, a first bias current generation circuit which generates a first bias current according to the first gain control current, a gain control voltage generation circuit which generates a gain control voltage changing with the control voltage, a first transistor which is emitter-grounded and in which an input signal and the first bias current are supplied to a base thereof, and a second transistor which is cascode-connected to the first transistor and in which the gain control voltage is supplied to a base thereof and a first output signal obtained by amplifying the input signal is output from a collector thereof.

According to one embodiment, an amplification circuit includes an amplifier having a gain and amplifying the input signal based on the gain, and a gain control signal generator controlling the gain based on an amplitude of the input signal. The gain obtained when the amplitude of the input signal is less than a first amplitude and when the amplitude of the input signal is greater than a second amplitude is lower than the gain obtained when the amplitude of the input signal is between the first and second amplitudes or when the amplitude of the input signal is one of the first and second amplitudes. The second amplitude is greater than or equal to the first amplitude.

Radio frequency (RF) power amplifier architectures and circuits providing compensated current and gain from turn-on to end of long signal burst intervals to counteract amplifier transistor thermal rise due to self-heating at turn-on. The RF receiver circuit may be implemented as one of a single chip device or as part of an integrated system of components for use in mobile communication systems.

Provided is a power amplification module that includes: an amplification transistor that has a constant power supply voltage supplied to a collector thereof, a bias current supplied to a base thereof and that amplifies an input signal input to the base thereof and outputs an amplified signal from the collector thereof; a first current source that outputs a first current that corresponds to a level control voltage that is for controlling a signal level of the amplified signal; and a bias transistor that has the first current supplied to a collector thereof, a bias control voltage connected to a base thereof and that outputs the bias current from an emitter thereof.