Abstract: A transformer filter arrangement including a transformer having a first winding and a second winding is provided. Both of the first and the second windings are located between an outer border and an inner border, which is inside the outer border. The transformer filter arrangement further includes at least one reactive sub circuit, each including at least one inductor. The first winding of the transformer is divided into a plurality of winding segments. At least a first one of the at least one reactive sub circuit being connected in series with the winding segments of the first winding between two such winding segments, and having at least one of the at least one inductor located inside said inner border.

Abstract: A technique for cancelling or reducing crosstalk signals between controlled oscillators in an integrated circuit is provided. The technique involves an arrangement adapted to reduce a crosstalk signal generated by a first controlled oscillator to a second oscillator both comprised in the integrated circuit, wherein both controlled oscillators are configured to output a respective clock signal. The arrangement comprises a detector adapted to detect the crosstalk signal generated by the first controlled oscillator to the second controlled oscillator, a crosstalk cancellation circuit adapted to generate a cancellation signal having an amplitude substantially the same as that of the crosstalk signal and a phase substantially opposite to that of the crosstalk signal, and a cancellation signal injector adapted to introduce the cancellation signal into the second controlled oscillator.

Abstract: A transmitter comprising a power amplifier, a phase modulator, a switched DC-DC converter, all operating in dual mode, and a controller is disclosed. The power amplifier is arranged to selectively operate either in a first mode or in a second mode, wherein the first mode is a linear mode and the second mode is a non-linear mode in order to save power with least increasing cost in hardware. The transmitter is adapted to operate at different allocated bandwidths, for different radio standards while keeping minimum power consumption governed by the controller. A transceiver, a communication device, a method and a computer program are also disclosed.

Abstract: A circuit for calibration measurements comprises a first and a second current source arranged to provide current outputs; a resistor connected between the first current source and a reference voltage; a capacitor connected between the second current source and the reference voltage; a discharge switch connected in parallel with the capacitor and arranged to selectively discharge the capacitor; a comparator circuit arranged to compare voltages across the resistor and the capacitor and output a signal when voltage across the capacitor reaches the voltage across the resistor; and a controller having a clock signal input and connected to the output of the comparator circuit.

Abstract: A receiver circuit comprising a transformer arrangement comprising a transformer structure, multiple and distributed receiver units arranged to be connected to one and same antenna via the transformer arrangement and arranged to operate on the same frequency and bandwidth as each other, wherein the transformer arrangement is arranged to input the antenna signal and to output signals at different output ports for the respective receiver unit, and a combiner circuit arranged to combine outputs of the multiple receiver units such that the combiner circuit outputs a combined signal, and corresponding communication apparatus, method and computer program are disclosed.

Abstract: A transmitter comprising a power amplifier, a phase modulator, a switched DC-DC converter, all operating in dual mode, and a controller is disclosed. The power amplifier is arranged to selectively operate either in a first mode or in a second mode, wherein the first mode is a linear mode and the second mode is a non-linear mode in order to save power with least increasing cost in hardware. The transmitter is adapted to operate at different allocated bandwidths, for different radio standards while keeping minimum power consumption governed by the controller. A transceiver, a communication device, a method and a computer program are also disclosed.

Abstract: Interference cancellation techniques may be implemented in a radio transceiver configured to transmit a radio-frequency transmit signal at a transmit frequency and having two or more local oscillators operative to simultaneously generate local oscillator signals, at corresponding local oscillator frequencies, for simultaneously down-converting two or more corresponding received radio-frequency signals. An example method begins with identifying one or more self-interfering frequencies, based on the local oscillator frequencies and the transmit frequency. A baseband cancellation signal is then generated by weighting and frequency-shifting a baseband representation of the transmit signal, based on the identified self-interfering frequencies. The baseband cancellation signal is then combined with a down-converted received signal, to obtain an interference-reduced baseband signal.

Abstract: A transformer filter arrangement including a transformer having a first winding and a second winding is provided. Both of the first and the second windings are located between an outer border and an inner border, which is inside the outer border. The transformer filter arrangement further includes at least one reactive sub circuit, each including at least one inductor. The first winding of the transformer is divided into a plurality of winding segments. At least a first one of the at least one reactive sub circuit being connected in series with the winding segments of the first winding between two such winding segments, and having at least one of the at least one inductor located inside said inner border.

Abstract: A quadrature signal generator comprises a resistor-capacitor, RC, polyphase filter and an inductor compensation arrangement. The inductor compensation arrangement comprises a first inductor connected between the first and the third output terminals, and a second inductor connected between the second and fourth output terminals. The first and second inductors are arranged to compensate for a capacitive load on the output terminals when in use. A beamforming arrangement, a communication device and a base station are also disclosed.

Abstract: A distributed power amplifier circuit is disclosed. The distributed power amplifier circuit comprises an amplifier arrangement comprising a plurality of sub amplifiers, each having an output port for outputting an output signal of the sub-amplifier and an output combiner network for combining the output signals from the sub amplifiers. The output combiner network includes, for each sub amplifier, an associated auto transformer operatively connected to the output port of the sub amplifier for receiving the output signal of the sub amplifier. The auto transformers each have a first interconnection terminal and a second interconnection terminal. The auto transformers are operatively connected in series via the interconnection terminals, thereby forming a chain of auto transformers having a first end and a second end, wherein the first end is arranged to be connected to an antenna.

Abstract: A complex intermediate frequency mixer (IFM) for frequency translating a received complex intermediate frequency, IF, signal, wherein the received complex IF signal comprises at least two frequency bands located at upper-side and lower-side of 0 Hz, is provided. The complex intermediate frequency mixer comprises a first, second, third and fourth mixer (M1, M2, M3, M4). The complex intermediate frequency mixer further comprises a first, second, third and fourth gain adjusting component (?1, ?2, ?2, ?1), connected to a first, second, third and fourth mixer output (M1-out, M2-out, M3-out, M4-out), respectively. Moreover, a first summing unit (S1), connected to a first gain output (?1-out), a fourth gain output (?1-out) and a third mixer output (M3-out) negated, and second summing unit (S2), connected to the second gain output (?2-out), the third gain output (?2-out) and the fourth mixer output (M4-out), are configured to output a first baseband complex signal of the received complex IF signal.

Abstract: A method and system for achieving increased efficiency in a quadrature modulated power amplifier (11) are disclosed. In some embodiments, a supply path (36, 40) and a gain path (38, 42) are provided in each of an I-channel and a Q-channel. The supply path (36, 40) produces a variable voltage and the gain path (38, 42) produces a gain control signal. The variable voltage and gain control signal are used by a variable gain power amplifier (44, 46) to modulate a local oscillator signal to produce a modulated radio signal.

Abstract: A complex intermediate frequency mixer (IFM) for frequency translating a received complex intermediate frequency, IF, signal, wherein the received complex IF signal comprises at least two frequency bands located at upper-side and lower-side of 0 Hz, is provided. The complex intermediate frequency mixer comprises a first, second, third and fourth mixer (M1, M2, M3, M4). The complex intermediate frequency mixer further comprises a first, second, third and fourth gain adjusting component (?1, ?2, ?2, ?1), connected to a first, second, third and fourth mixer output (M1-out, M2-out, M3-out, M4-out), respectively. Moreover, a first summing unit (S1), connected to a first gain output (?1-out), a fourth gain output (?1-out) and a third mixer output (M3-out) negated, and second summing unit (S2), connected to the second gain output (?2-out), the third gain output (?2-out) and the fourth mixer output (M4-out), are configured to output a first baseband complex signal of the received complex IF signal.

Abstract: A transmitter comprising a power amplifier, a phase modulator, a switched DC-DC converter, all operating in dual mode, and a controller is disclosed. The power amplifier is arranged to selectively operate either in a first mode or in a second mode, wherein the first mode is a linear mode and the second mode is a non-linear mode in order to save power with least increasing cost in hardware. The transmitter is adapted to operate at different allocated bandwidths, for different radio standards while keeping minimum power consumption governed by the controller. A transceiver, a communication device, a method and a computer program are also disclosed.

Abstract: A complex intermediate frequency mixer (IFM) for frequency translating a received complex intermediate frequency, IF, signal, wherein the received complex IF signal comprises at least two frequency bands located at upper-side and lower-side of 0 Hz, is provided. The complex intermediate frequency mixer comprises a first, second, third and fourth mixer (M1, M2, M3, M4). The complex intermediate frequency mixer further comprises a first, second, third and fourth gain adjusting component (?1, ?2, ?2, ?1), connected to a first, second, third and fourth mixer output (M1-out, M2-out, M3-out, M4-out), respectively. Moreover, a first summing unit (S1), connected to a first gain output (?1-out), a fourth gain output (?1-out) and a third mixer output (M3-out) negated, and second summing unit (S2), connected to the second gain output (?2-out), the third gain output (?2-out) and the fourth mixer output (M4-out), are configured to output a first baseband complex signal of the received complex IF signal.

Abstract: The disclosure relates to a Complex Intermediate Frequency (CIF)-based receiver adapted to process a received signal comprising a signal component at a desired frequency and a signal component as an image frequency. The CIF-based receiver determines the power of the received signal by calibrating the receiver to minimize the power of the signal component at the image frequency that interferes with the signal component at the desired frequency, introduces signal leakage from the image frequency to intentionally degrade the quality of the signal component at the desired frequency, and determines the power of the signal component at the image frequency based on the amount of degradation.

Abstract: A low noise amplifier comprises at least one amplifying transistor (Ts1; Ts2) configured in a common source configuration to receive an input signal (RFin) at a gate terminal and provide an amplified signal at a drain terminal and at least one feedback path arranged to couple a part of the amplified signal back to the gate terminal and comprising a feedback impedance. The low noise amplifier further comprises a self-coupled step-up transformer having at least one primary winding (Lp) connected to a supply voltage (Vdd) and the drain terminal of the at least one amplifying transistor and at least one self-coupled secondary inductor winding (Lf1; Lf2) arranged in the feedback path. The low noise amplifier provides a better suppression for out-band interference and at the same time it has a wider input match bandwidth, decent conversion gain and decent noise figure without increasing power consumption.

Abstract: Interference cancellation techniques may be implemented in a radio transceiver configured to transmit a radio-frequency transmit signal at a transmit frequency and having two or more local oscillators operative to simultaneously generate local oscillator signals, at corresponding local oscillator frequencies, for simultaneously down-converting two or more corresponding received radio-frequency signals. An example method begins with identifying one or more self-interfering frequencies, based on the local oscillator frequencies and the transmit frequency. A baseband cancellation signal is then generated by weighting and frequency-shifting a baseband representation of the transmit signal, based on the identified self-interfering frequencies. The baseband cancellation signal is then combined with a down-converted received signal, to obtain an interference-reduced baseband signal.

Abstract: A circuit converts a single-ended signal to differential signals that are balanced to have the same amplitudes and opposite phases relative to a reference point of the differential signals. The circuit includes a balance tunable balun, a detector, and a controller. The balance tunable balun has a primary winding, a secondary winding, a control input, and a switched resistor-capacitor (RC) network. The primary winding receives the single-ended signal and the secondary winding outputs the differential signals. The control input receives a control signal and the switched RC network controls the reference point of the differential signals responsive to this control signal. The detector detects the output imbalance and the controller generates the control signal to control the switched RC network to effectively adjust the reference point as needed to reduce that output imbalance. The circuit produces well balanced differential signals over a wide range of signal frequencies.

Abstract: A technique for cancelling or reducing crosstalk signals between controlled oscillators in an integrated circuit is provided. The technique involves an arrangement adapted to reduce a crosstalk signal generated by a first controlled oscillator to a second oscillator both comprised in the integrated circuit, wherein both controlled oscillators are configured to output a respective clock signal. The arrangement comprises a detector adapted to detect the crosstalk signal generated by the first controlled oscillator to the second controlled oscillator, a crosstalk cancellation circuit adapted to generate a cancellation signal having an amplitude substantially the same as that of the crosstalk signal and a phase substantially opposite to that of the crosstalk signal, and a cancellation signal injector adapted to introduce the cancellation signal into the second controlled oscillator.