A device for transmitting data includes a transmitter for generating a frequency-modulated output signal. The transmitter includes a phase-locked loop for adjusting an output frequency of the output signal to a carrier frequency, and a coupling circuit for coupling a data stream into the phase-locked loop. The output signal modulated in frequency by the coupled-in data stream has an output frequency variable over time, and the coupling circuit includes a compensation unit, which couples a compensation signal into the phase-locked loop. The compensation signal compensates at least approximately for an adjustment of the output frequency to the carrier frequency carried out by the phase-locked loop.

Embodiments described herein include a receiver, a method, and a plurality of high-pass filters for demodulating a radio frequency (RF) signal. An example receiver includes a plurality of high-pass filters. The receiver includes a demodulator configured to demodulate an RF signal received at an input of the demodulator and configured to output a demodulated signal. The receiver also includes a plurality of high-pass filters connected to an output of the demodulator. The plurality of high-pass filters are configured to receive the demodulated signal and configured to high-pass filter the demodulated signal. The plurality of high-pass filters are configured to operate with a first set of filter responses during a first time period of the demodulated signal and configured to operate with a second set of filter responses during a second time period of the demodulated signal.

A mixer in a receiver converts a sounding sequence of alternating ones and zeros to an intermediate frequency signal. A digital mixer converts the intermediate frequency signal to a baseband signal that contains a positive tone and a negative tone. A frequency offset correction circuit generates frequency offset corrections based on frequency offset estimates of the frequency offset between a transmitter of the sounding sequence and the receiver. A frequency adjustment circuit adjusts a frequency of the mixer or the digital mixer to thereby center the positive tone and the negative tone around DC. DFT circuits perform single bin DFTs respectively centered on the positive and negative tones. Phases of the positive and negative tones are calculated based on outputs of the DFT circuits and the phases are used to determine fractional time value associated with a distance measurement between the transmitter and receiver.

A quadrature detection unit subjects an FM signal to quadrature detection using a local oscillation signal and outputs a base band signal. A first correction unit and a second correction unit correct the base band signal using a DC offset correction value. A DC offset detection unit subjects the corrected base band signal to rectangular to polar conversion and derives the DC offset correction value such that amplitudes in a plurality of phase domains defined in an IQ plane approximate each other. An FM detection unit subjects the corrected base band signal to FM detection and generates a detection signal. An addition unit adds an offset to the detection signal. An AFC unit generates a control signal for controlling a frequency of a local oscillation signal based on the detection signal to which the offset is added.

A first local oscillator generates a modulation signal of a predetermined frequency. A second local oscillator outputs a local oscillation signal frequency-modulated by using the modulation signal from the first local oscillator. A quadrature detection unit subjects an FM signal to quadrature detection by using the local oscillation signal output from the second local oscillator and outputs a base band signal. A first reduction unit and a second reduction unit reduce a direct current component contained in the base band signal. A correction unit restores the direct current component by correcting the base band signal such that the base band signal is centered around an origin of a polar coordinate system on an IQ plane. An FM detection unit subjects the corrected base band signal to FM detection and generates a detection signal.

System, methods and apparatus are described that improve link turnaround performance in a differentially driven link. A method performed at a first device coupled to a two-wire serial link includes transmitting from the first device first differentially-encoded data to a second device over the two-wire serial link during a first time period, receiving at the first device second differentially-encoded data from the second device over the two-wire serial link during a second time period, and driving by the first device both wires of the two-wire serial link to a common voltage level during a third time period, the third time period spanning a link turnaround period between the first time period and the second time period. Both wires of the two-wire serial link are driven toward the common voltage level by the second device during the third time period.

A mixer in a receiver converts a sounding sequence of alternating ones and zeros to an intermediate frequency signal. A digital mixer converts the intermediate frequency signal to a baseband signal that contains a positive tone and a negative tone. A frequency offset correction circuit generates frequency offset corrections based on frequency offset estimates of the frequency offset between a transmitter of the sounding sequence and the receiver. A frequency adjustment circuit adjusts a frequency of the mixer or the digital mixer to thereby center the positive tone and the negative tone around DC. DFT circuits perform single bin DFTs respectively centered on the positive and negative tones. Phases of the positive and negative tones are calculated based on outputs of the DFT circuits and the phases are used to determine fractional time value associated with a distance measurement between the transmitter and receiver.

A mixer is connected to a signal generator and an antenna and outputs a signal at an intermediate frequency. A PLL demodulator subjects the signal at the intermediate frequency from the mixer to PLL demodulation. An amplifier amplifies a signal from the PLL demodulator. A detector detects an amount of shift occurring in the PLL demodulator. A detector detects a gain of the amplifier. An FSK demodulator subjects a signal from the amplifier to FSK demodulation. An AFC unit detects a frequency offset in the signal from the amplifier and causes the signal generator to make a correction for the frequency offset detected.

An electronic assembly including a plurality of electrically conductive elements separated by insulative material and a digital FM demodulator circuit coupled to some of the electrically conductive elements. The FM demodulator circuit having an FM detector circuit and a DC drift reducing circuit. The FM detector circuit has a detector input and a detector output that is the output of a comparator that is AC coupled to the rest of the FM detector circuit, the detector input receiving an input signal. The DC drift reducing circuit is electrically coupled to the detector output of the comparator, the DC drift reducing circuit detecting a DC drift of the detector output, the DC drift reducing circuit being additionally coupled to an input of the comparator, the DC drift reducing circuit substantially eliminating DC drift at the output of the FM demodulator circuit.

A mixer is connected to a signal generator and an antenna and outputs a signal at an intermediate frequency. A PLL demodulator subjects the signal at the intermediate frequency from the mixer to PLL demodulation. An amplifier amplifies a signal from the PLL demodulator. A detector detects an amount of shift occurring in the PLL demodulator. A detector detects a gain of the amplifier. An FSK demodulator subjects a signal from the amplifier to FSK demodulation. An AFC unit detects a frequency offset in the signal from the amplifier and causes the signal generator to make a correction for the frequency offset detected.