Abstract: Switched-mode power supplies (SMPSs) and their control methods for radio frequency (RF) power amplifiers in battery-powered wireless transmitter devices involve a Boost-type SMPS and a Buck-type SMPS in cascade connection which are controlled so that high efficiency is maintained for various loads and transmission power levels. The Boost SMPS and the Buck SMPS can be controlled based on the mode of operation of the transmitter, such as the actual battery voltage, the needed output power, the selected frequency band, the selected RF power amplifier (PA), the selected modulation method of the transmission signal, and/or the selected PA voltage control method, such as the envelope elimination and restoration (EER) technique, the envelope tracking (ET) technique, or the power-level tracking (PT) technique.

Abstract: A method is disclosed to operate a multi-mode multi-timeslot RF transmitter, as is an RF transmitter that includes a control unit that operates in accordance with the method. The method includes, prior to a first timeslot, setting a plurality of control signals for the RF transmitter in accordance with a first modulation format used during the first timeslot; and during a guard period between the first timeslot and a next, temporally adjacent timeslot, setting the plurality of control signals for the RF transmitter in accordance with a second modulation format used during the second timeslot, where the first modulation format differs from the second modulation format.

Abstract: A transmitter for generating modulated signals is shown, wherein in a first-type operating mode, a first digital signal is input into a digital-to-analog converter to obtain a first analog signal that is input into a first-type unit, in which a first-type modulated signal is generated in dependence on at least the first analog signal; and wherein in a second-type operating mode, a second digital signal is input into the digital-to-analog converter to obtain a second analog signal that is input into a second-type unit, in which a second-type modulated signal is generated in dependence on at least the second analog signal. Correspondingly, a wireless communication device is shown, as well as a base station, a module in a wireless communication device, a module in a base station, an integrated circuit, a method, a computer program and a computer program product.

Abstract: A method is disclosed to operate a dual mode multi-timeslot RF transmitter, as is an RF transmitter that include a control unit that operates in accordance with the method. The method includes, prior to a first timeslot, setting a plurality of control signals for the RF transmitter in accordance with a first modulation format used during the first timeslot; and during a guard period between the first timeslot and a next, temporally adjacent timeslot, setting the plurality of control signals for the RF transmitter in accordance with a second modulation format used during the second timeslot, where the first modulation format differs from the second modulation format.

Abstract: The object of the invention is the compensation of the drift in a detector and a control signal (TXC), particularly in the control of the transmit power (RFOUT) of an RF time division TDMA signal (RFIN), for the control of which there is performed a power detection. According to the invention the voltage difference between the output voltage of the detection and the control signal is stored during a transmission pause, and during the transmission state the stored voltage difference is used to compensate the temperature drift of the detection and the control signal (TXC) in generating the gain control voltage (VCTRL).

Abstract: The invention relates to a bandpass filter that follows the frequency of an input signal especially for reducing the noise on the receive band of mobile communications devices. More specifically the invention relates to a method and arrangement for tuning a resonator (100), where an input signal feeds the resonator in such a manner that the resonator oscillates at, the frequency of the input signal, and where the center frequency of the pass band of the resonator is set substantially to the frequency of the input, signal. In accordance with the invention, there is generated (200) a difference signal (Vc, Ve) proportional to the phase difference (&Dgr;&phgr;) between the input signal voltage (Vi) and resonator voltage (Vo) and the resonance frequency of the resonator is changed using the difference signal in such a manner that said phase difference becomes smaller.

Abstract: The invention relates to a method and radio receiver for attenuating spurious signals when receiving (6 to 12) radio signals, when radio signals are mixed (10) to a second frequency, which may be the baseband frequency, for example. Spurious signals are caused by balance errors in the mixer (10) which result from component value fluctuations within tolerance limits. According to the invention, mixing is balanced by setting (12) variable-level bias voltages and/or currents to transistors in the mixer circuit (10). An advantage of the invention is that even-order spurious signals caused by balance errors in the mixing of a signal to a second frequency are considerably attenuated. The invention finds particular utility in a mobile communications device, for example.

Abstract: The active component (400, 500) of a radio device comprises a first transistor (Q1) and a second transistor (Q2). The differential input of the active component comprises a first input line (RF+) and a second input line (RF−), of which the first input line is coupled to the base of the first transistor (Q1) and the second input line is coupled to the base of the second transistor (Q2). In order to match the input impedance there is cross-feedback (Rfb′) between the first transistor (Q1) and the second transistor (Q2).