Abstract: A method and arrangement for transmitting and receiving RF signals, associated with different radio interfaces of communication systems, employ a direct conversion based transceiver which substantially comprises one receive signal branch and one transmit signal branch. Mixing frequencies of the different systems are generated by a single common by use of an output frequency divider in combination with the synthesizer, and by use of filtering corresponding to a system channel bandwidth by means of a controllable low-pass filter operating at baseband frequency.

Abstract: A method and arrangement for transmitting and receiving RF signals, associated with different radio interfaces of communication systems, employ a direct conversion based transceiver which substantially comprises one receive signal branch and one transmit signal branch. Mixing frequencies of the different systems are generated by a single common by use of an output frequency divider in combination with the synthesizer, and by use of filtering corresponding to a system channel bandwidth by means of a controllable low-pass filter operating at baseband frequency.

Abstract: A method and arrangement for transmitting and receiving RF signals, associated with different radio interfaces of communication systems, employ a direct conversion based transceiver which substantially comprises one receive signal branch and one transmit signal branch. Mixing frequencies of the different systems are generated by a single common by use of an output frequency divider in combination with the synthesizer, and by use of filtering corresponding to a system channel bandwidth by means of a controllable low-pass filter operating at baseband frequency.

Abstract: A method and arrangement for transmitting and receiving RF signals, associated with different radio interfaces of communication systems, employ a direct conversion based transceiver which substantially comprises one receive signal branch and one transmit signal branch. Mixing frequencies of the different systems are generated by a single common by use of an output frequency divider in combination with the synthesizer, and by use of filtering corresponding to a system channel bandwidth by means of a controllable low-pass filter operating at baseband frequency.

Abstract: A method and arrangement for transmitting and receiving RF signals, associated with different radio interfaces of communication systems, employ a direct conversion based transceiver which substantially comprises one receive signal branch and one transmit signal branch. Mixing frequencies of the different systems are generated by a single common by use of an output frequency divider in combination with the synthesizer, and by use of filtering corresponding to a system channel bandwidth by means of a controllable low—pass filter operating at baseband frequency.

Abstract: A method and arrangement for transmitting and receiving RF signals, associated with different radio interfaces of communication systems, employ a direct conversion based transceiver which substantially comprises one receive signal branch and one transmit signal branch. Mixing frequencies of the different systems are generated by a single common by use of an output frequency divider in combination with the synthesizer, and by use of filtering corresponding to a system channel bandwidth by means of a controllable low-pass filter operating at baseband frequency.

Abstract: A method and arrangement for transmitting and receiving RF signals, associated with different radio interfaces of communication systems, employ a direct conversion based transceiver which substantially comprises one receive signal branch and one transmit signal branch. Mixing frequencies of the different systems are generated by a single common by use of an output frequency divider in combination with the synthesizer, and by use of filtering corresponding to a system channel bandwidth by means of a controllable low-pass filter operating at baseband frequency.

Abstract: A method and arrangement for transmitting and receiving RF signals, associated with different radio interfaces of communication systems, employ a direct conversion based transceiver which substantially comprises one receive signal branch and one transmit signal branch. Mixing frequencies of the different systems are generated by a single common by use of an output frequency divider in combination with the synthesizer, and by use of filtering corresponding to a system channel bandwidth by means of a controllable low-pass filter operating at baseband frequency.

Abstract: There is provided a solution for dual channel transmission in a radio communication device. Both transmission signals to be transmitted on different channels are mixed two times by using oscillator signals having the same frequencies for both transmission signals, and the transmission circuitry is arranged to process the signals so that the transmission signals are nevertheless up-converted to different frequency channels.

Abstract: A method and arrangement for transmitting and receiving RF signals, associated with different radio interfaces of communication systems, employ a direct conversion based transceiver which substantially comprises one receive signal branch and one transmit signal branch. Mixing frequencies of the different systems are generated by a single common by use of an output frequency divider in combination with the synthesizer, and by use of filtering corresponding to a system channel bandwith by means of a controllable low-pass filter operating at baseband frequency.

Abstract: There is provided a solution for dual channel transmission in a radio communication device. Both transmission signals to be transmitted on different channels are mixed two times by using oscillator signals having the same frequencies for both transmission signals, and the transmission circuitry is arranged to process the signals so that the transmission signals are nevertheless up-converted to different frequency channels.

Abstract: An apparatus configured to separate from a received radio frequency (RF) signal a first low-frequency signal and a second low-frequency signal having different phases, up-convert the first low-frequency signal and the second low-frequency signal into a first intermediate frequency signal and a second intermediate frequency signal, respectively, and amplify the first and the second intermediate-frequency signals.

Abstract: On a radio frequency signal path a transmission phase shifter causes a phase shift. From a first end of said phase shifter comes a first sample, and from a second end of said phase shifter comes a second sample. Another phase shifter changes the phase of the second sample by the same magnitude as said transmission phase shifter. A measurement circuit combines the phase-shifted second sample with a phase-inverted version of the first sample to produce an output indicative of a power level of the original signal on the radio frequency signal path.

Abstract: A passive amplifier structure capable of multiplying the voltage of an input signal is provided. In a first stage, a first and a second capacitance are connected between a first and a second input port of a balanced input port in response to a first oscillator signal. In a second stage, in response to a second oscillator signal having a phase different from that of the first oscillator signal, the first capacitance is connected between the first input port and a third capacitance and the second capacitance is connected between the second input port and the third capacitance. An output voltage over the third capacitance is obtained from terminals of the third capacitance. Presented embodiments also describe an automatic gain control feature.

Abstract: An apparatus configured to separate from a received radio frequency (RF) signal a first low-frequency signal and a second low-frequency signal having different phases, up-convert the first low-frequency signal and the second low-frequency signal into a first intermediate frequency signal and a second intermediate frequency signal, respectively, and amplify the first and the second intermediate-frequency signals.

Abstract: A frequency-mixing device performing voltage multiplying and low-pass filtering operations in addition to the frequency mixing is provided. The three operations may be carried out with the same components by designing the frequency mixer appropriately. The frequency mixer comprises a balanced input port to receive a balanced input signal, an oscillator signal input port to receive a first and a second oscillator signal and a first, a second, and a third capacitance. First switching means are arranged to connect, in response to the first oscillator signal, the first and the second capacitance between a first and a second input port of the balanced input port. Second switching means are arranged to connect, in response to the second oscillator signal, the first capacitance between the first input port and the third capacitance and the second capacitance between the second input port and the third capacitance. An output port is connected to terminals of the third capacitance.

Abstract: A circuit for rounding the edges of a digital pulse so as to reduce interference has a first rounding block, a second rounding block and an output stage. The first rounding block rounds the second and fourth pulse edges so as to prolong rising and falling time of the digital pulse. The second rounding block rounds the first and third pulse edges in accordance with non-linear characteristics of a semiconductor of the second rounding block. The output stage is a feedback circuit where the first rounding block is coupled with the second rounding block and the second rounding block is coupled with the feedback circuit.

Abstract: A frequency-mixing device performing voltage multiplying and low-pass filtering operations in addition to frequency mixing is provided. The three operations may be carried out with the same components by designing the frequency mixer appropriately. The frequency mixer comprises a first capacitance connected in series to the input of the frequency-mixing device, a first switch connected in parallel to the first capacitance, a second switch connected in series to the first capacitance, and a second capacitance connected in parallel to the second switching means. The switches are controlled by a local oscillator signal to close and open alternately according to a change in the voltage level of the first oscillator signal.

Abstract: A method and arrangement is shown for performing analog signal processing tasks like impedance matching, phase shifting, and/or signal filtering on a signal path from a signal source to a load so that a number of electrical components is smaller than that of solutions according to prior art for performing corresponding analog signal processing tasks. The signal source can be e.g. a power amplifier of a transmitter and the load can be e.g. an antenna of the transmitter. A solution is shown in which a same ninety degree phase shifter element (910) is used for performing more than one of the analog signal processing tasks of the kind mentioned above.

Abstract: A method and arrangement for transmitting and receiving RF signals, associated with different radio interfaces of communication systems, employ a direct conversion based transceiver which substantially comprises one receive signal branch and one transmit signal branch. Mixing frequencies of the different systems are generated by a single common by use of an output frequency divider in combination with the synthesizer, and by use of filtering corresponding to a system channel bandwith by means of a controllable low-pass filter operating at baseband frequency.