Abstract: A method and a device for tuning power amplifier (PA, 203) properties such as back-off. A peak-to-average value (PAR) of the amplifier input signal is first obtained by control means (206) and then used for adjusting the power amplifier (203) with tuning means (204, 208, 210) functionally connected to the amplifier (203). The suggested solution is advantageously exploited in a wireless communications device like a mobile terminal to optimize the performance thereof by, for example, reducing the power dissipation in the transmitter.

Abstract: An RF power amplifier module can be used without a matching device between the power amplifier module and an antenna. The power amplifier module is constructed and operated to detect, protect and maintain the performance of the power amplifier in the presence of severe VSWR load mismatches, without requiring the use of external circuitry. The RF power amplifier module includes integral detection circuitry for generating a first detection signal having a value that is indicative of the current flowing through an output power transistor and a second detection signal having a value that is indicative the voltage appearing at the output of the output power transistor, as well as integral compensation circuitry for controlling the generation of a plurality of bias current and bias voltage signals to have values that are a function of the values of the first and second detection signals, as well as the current output power level of the RF power amplifier module.

Abstract: A method for managing transmission conditions in a mobile telecommunication system according to movement of a mobile terminal is provided. The mobile terminal is having a communication link with a base station. The movement of the mobile terminal is monitored, and then a database is checked for the most optimal transmission conditions for the monitored movement of the mobile terminal, and action is taken to change the transmission conditions of the communication link upon detecting, in the database, transmission conditions providing a more optimal communication link for the current movement of the mobile terminal than the transmission conditions currently being used for the communication link.

Abstract: A RF transmitter has at least one amplifier having an input terminal for receiving a phase modulated signal to be transmitted on an RF carrier and an input node for receiving a modulation signal for amplitude modulating the RF carrier. The RF transmitter further includes an amplitude modulator having an output coupled to the input node of the power amplifier through a low-pass filter. The low-pass filter includes at least one variable filter component for varying a bandwidth of the low-pass filter. In a preferred embodiment an envelope elimination and restoration (EER) RF transmitter includes at least one power RF amplifier having the input terminal for receiving the phase modulated signal to be transmitted on the RF carrier, and further including an input power node for receiving a modulated voltage for amplitude modulating the RF carrier.

Abstract: A transmission device and method are shown, wherein an amplification is implemented which can be changed between a switched operation mode and linear operation mode as desired, depending on which mode of operation best meets the needs of the radio system in use. This opens the possibility of using the same hardware for different systems.

Abstract: A method and a device for tuning power amplifier (PA, 203) properties such as back-off. A peak-to-average value (PAR) of the amplifier input signal is first obtained by control means (206) and then used for adjusting the power amplifier (203) with tuning means (204, 208, 210) functionally connected to the amplifier (203). The suggested solution is advantageously exploited in a wireless communications device like a mobile terminal to optimize the performance thereof by, for example, reducing the power dissipation in the transmitter.

Abstract: A RF transmitter has at least one amplifier having an input terminal for receiving a phase modulated signal to be transmitted on an RF carrier and an input node for receiving a modulation signal for amplitude modulating the RF carrier. The RF transmitter further includes an amplitude modulator having an output coupled to the input node of the power amplifier through a low-pass filter. The low-pass filter includes at least one variable filter component for varying a bandwidth of the low-pass filter. In a preferred embodiment an envelope elimination and restoration (EER) RF transmitter includes at least one power RF amplifier having the input terminal for receiving the phase modulated signal to be transmitted on the RF carrier, and further including an input power node for receiving a modulated voltage for amplitude modulating the RF carrier.

Abstract: A mobile telephone including a hearing aid compatible system for coupling an output of the mobile telephone to a hearing aid device of a user; and a metal detector system adapted to detect a metal object brought into proximity relative to the mobile telephone.

Abstract: An RF power amplifier module can be used without a matching device between the power amplifier module and an antenna. The power amplifier module is constructed and operated to detect, protect and maintain the performance of the power amplifier in the presence of severe VSWR load mismatches, without requiring the use of external circuitry. The RF power amplifier module includes integral detection circuitry for generating a first detection signal having a value that is indicative of the current flowing through an output power transistor and a second detection signal having a value that is indicative the voltage appearing at the output of the output power transistor, as well as integral compensation circuitry for controlling the generation of a plurality of bias current and bias voltage signals to have values that are a function of the values of the first and second detection signals, as well as the current output power level of the RF power amplifier module.

Abstract: The invention relates to a matching circuit for adapting an amplifier to load impedance at various output power levels of the amplifier, and a method for adapting the amplifier to load impedance at various output power levels of the amplifier. The matching circuit comprises an LC circuit, i.e. an electric circuit switching consisting of at least one coil and at least one capacitor for tuning harmonic signals resulting from amplifier non-linearities. At least one capacitor of the LC circuit (600, 602, 604, 606) is an adjustable microelectromechanical (MEMS) capacitor (602, 606). The LC circuit comprises an interface for receiving control signals (220) adjusting capacitance of the microelectromechanical (MEMS) capacitor. The control signals (220) adjust the capacitance of the microelectromechanical (MEMS) capacitor (602, 606) such that the LC circuit (600, 602, 604, 606) resonates at the frequency of the harmonic signal to be tuned.

Abstract: The invention relates to a matching circuit for adapting an amplifier to load impedance at various output power levels of the amplifier, and a method for adapting the amplifier to load impedance at various output power levels of the amplifier. The matching circuit comprises an LC circuit, i.e. an electric circuit switching consisting of at least one coil and at least one capacitor for tuning harmonic signals resulting from amplifier non-linearities. At least one capacitor of the LC circuit (600, 602, 604, 606) is an adjustable microelectromechanical (MEMS) capacitor (602, 606). The LC circuit comprises an interface for receiving control signals (220) adjusting capacitance of the microelectromechanical (MEMS) capacitor. The control signals (220) adjust the capacitance of the microelectromechanical (MEMS) capacitor (602, 606) such that the LC circuit (600, 602, 604, 606) resonates at the frequency of the harmonic signal to be tuned.

Abstract: The course of an oscillating signal is controlled in mutually alternative first active component (31) and second active component (32), both of which can be set into active state by a certain first value of a control signal brought to the component and which are in inactive state with a certain second value of the control signal. The signal is directed to pass through the first active component (31) by setting it into active state by a control signal (33) brought to it. At the same time, the second active component (32) is prevented from affecting the course of the signal by setting a control signal brought to it to a second value (107, 111).

Abstract: A transmitter (2) for communication devices according to the invention comprises a high-frequency power amplifier for amplifying the high-frequency signal to be transmitted, which high-frequency power amplifier includes an output stage for giving an amplified high-frequency signal, and measuring devices for measuring the power (Pdc) of the high-frequency signal. The measuring devices comprise devices (A1, RECT1, INT1, A2, RECT2, INT2) for measuring the voltage (VCE) and current (IE) of the high-frequency signal in said output stage, and means (M1, INT3) for calculating the power of the high-frequency signal on the basis of the measured high-frequency voltage (Vmeas) and high-frequency current (Imeas). A mobile station (1) according to the invention has a transmitter (2) for transmitting signals, which transmitter (2) includes a high-frequency power amplifier for amplifying the high-frequency signal to be transmitted.

Abstract: A radio frequency amplifier having a power transistor (Q1) to the base of which is coupled a radio frequency signal to be amplified. An amplified radio frequency signal is provided at the collector of the power transistor (Q1). A control transistor (Qc) has its base coupled to the base of the power transistor (Q1) while a driver transistor (Q2) provides a control bias signal to the bases of the control and power transistors. A differential amplifier (Qd1, Qd2) has a first input coupled to an input bias signal and an output coupled to the base of the driver transistor (Q2). The collector of the control transistor (Qc) is coupled to a second input of the differential amplifier to provide a negative feedback signal to the differential amplifier and the driver transistor (Q2) and thereby to stabilise the operating point of the power transistor (Q1).