Abstract: The present disclosure relates to a front-end system for a radio device comprising: a charge generator circuit arranged for receiving a digital baseband signal, a first converter circuit arranged for calculating at least one charge value based on the digital baseband signal, a second converter circuit arranged for converting the at least one charge value into at least one electrical charge, and a modulator circuit arranged for generating a radio frequency signal based on the at least one electrical charge and at least one local oscillator signal.

Abstract: A conversion circuit is disclosed. In one aspect, the conversion circuit includes a first input terminal for receiving a digital signal. The conversion circuit includes a second input terminal for receiving a bias voltage signal. The conversion circuit includes an output terminal for outputting a current. The conversion circuit includes a first and a second switch transistor connected to the first input terminal for receiving the digital signal. The conversion circuit includes a first and a second current source transistor connected to the second input terminal for receiving the bias voltage signal. The conversion circuit further includes a first branch, wherein the first switch transistor is connected to the output terminal via the first current source transistor. The conversion circuit further includes a second branch, wherein the second current source transistor is connected to the output terminal via the second switch transistor.

Abstract: The present disclosure relates to a delay control circuit arranged for adding delay to a signal. The delay control circuit includes a driver circuit arranged to receive a first signal and to output a second signal. The driver circuit includes a variable load arranged for outputting the second signal by adding delay to the first signal. The delay control circuit also includes a control circuit arranged to receive the first signal and to control the variable load of the driver circuit based on a current state of the first signal and on a control signal indicative of an amount of delay to be added to the first signal in the current state.

Abstract: A conversion circuit is disclosed. In one aspect, the conversion circuit includes a first input terminal for receiving a digital signal. The conversion circuit includes a second input terminal for receiving a bias voltage signal. The conversion circuit includes an output terminal for outputting a current. The conversion circuit includes a first and a second switch transistor connected to the first input terminal for receiving the digital signal. The conversion circuit includes a first and a second current source transistor connected to the second input terminal for receiving the bias voltage signal. The conversion circuit further includes a first branch, wherein the first switch transistor is connected to the output terminal via the first current source transistor. The conversion circuit further includes a second branch, wherein the second current source transistor is connected to the output terminal via the second switch transistor.

Abstract: The present disclosure relates to a front-end system for a radio device comprising: a charge generator circuit arranged for receiving a digital baseband signal, a first converter circuit arranged for calculating at least one charge value based on the digital baseband signal, a second converter circuit arranged for converting the at least one charge value into at least one electrical charge, and a modulator circuit arranged for generating a radio frequency signal based on the at least one electrical charge and at least one local oscillator signal.

Abstract: The present disclosure relates to a direct digital radio frequency modulator that includes a plurality of input terminals arranged to receive a multi-bit digital signal, and a plurality of converter circuits. In one example, the converter circuits are arranged to receive at an input terminal one bit of the multi-bit digital signal and to provide at a converter circuit output terminal an analog signal in accordance to the one bit. In the present example, a converter circuit includes an input transistor arranged to receive the one bit for enabling the converter circuit to produce the analog signal, a current source transistor, an additional transistor in cascode to the current source transistor, and a frequency modulator output terminal connected to the output terminal of each converter circuit for providing an analog output signal.

Abstract: Transmitter circuits for generating baseband signals having low receiver-band noise are disclosed. In one embodiment, the transmitter circuit comprises an active filtering-and-amplifying component comprising a first input configured to receive a first input signal, and a first output configured to output a first output signal. The transmitter circuit further comprises a passive filtering component comprising a second input connected to the first output and configured to receive the first output signal, a passive pole arrangement comprising a number of switchable resistance elements and a capacitance element connected across the plurality of switchable resistance elements, and a second output configured to output a second output signal having reduced noise as compared to the first output signal. The transmitter still further comprises a number of feedback loops connecting the passive filtering component to the first input.

Abstract: A radio frequency modulator is disclosed that includes a finite impulse response filter including a first modulator element having a first gain and configured to receive a first input signal and produce a first output signal, a second modulator element having a second gain and configured to receive a second input signal delayed with respect to the first input signal and produce a second output signal, a third modulator element having a third gain and configured to receive a third input signal delayed with respect to the second input signal and produce a third output signal, and a fourth modulator element having a fourth gain and configured to receive a fourth input signal delayed with respect to the third input signal and produce a fourth output signal. The first, second, third, and fourth gains are each different and are based on coefficients of the finite impulse response filter.

Abstract: Transmitter circuits for generating baseband signals having low receiver-band noise are disclosed. In one embodiment, the transmitter circuit comprises an active filtering-and-amplifying component comprising a first input configured to receive a first input signal, and a first output configured to output a first output signal. The transmitter circuit further comprises a passive filtering component comprising a second input connected to the first output and configured to receive the first output signal, a passive pole arrangement comprising a number of switchable resistance elements and a capacitance element connected across the plurality of switchable resistance elements, and a second output configured to output a second output signal having reduced noise as compared to the first output signal. The transmitter still further comprises a number of feedback loops connecting the passive filtering component to the first input.