A SWIPT (simultaneous wireless information and power transfer) device based on the modulation of power supply ripple of magnetron includes a magnetron power supply, a magnetron, an IF (intermediate frequency) signal generator and a first capacitor. The first and second cathode power lines are provided between two ends of the magnetron power supply and two ends of the cathode of the magnetron respectively. One end of the first capacitor is connected with the IF signal generator, and another end of the first capacitor is connected with the first cathode power line. A SWIPT method includes applying an IF signal which is equivalent to the ripple of anode voltage of the magnetron to the anode voltage of the magnetron; taking a resonance signal excited by the magnetron as a local oscillation signal; generating a new signal at an output end of the magnetron, and radiating the new signal through an antenna.

A feed unit includes: a power transmission section configured to perform power transmission with use of a magnetic field or an electronic field; a power limiting section provided on a power supply line from an external power source to the power transmission section; and a control section provided on a side closer to the external power source than the power limiting section, and including a power transmission control section, the power transmission control section being configured to control the power transmission.

A feed unit includes: a power transmission section configured to perform power transmission with use of a magnetic field or an electronic field; a power limiting section provided on a power supply line from an external power source to the power transmission section; and a control section provided on a side closer to the external power source than the power limiting section, and including a power transmission control section, the power transmission control section being configured to control the power transmission.

The present invention provides an amplitude modulator, which is disposed in an area through which a magnetic field flows so as to modulate amplitudes, comprising: a substrate; a first driving electrode which receives a first frequency signal and a second frequency signal supplied from the substrate and carries out resonant motion by the magnetic field; and a second driving electrode for receiving the second frequency signal and carries out resonant motion by the first driving electrode and the magnetic field, wherein a modulated signal is generated by modulating the amplitudes of the first and second frequency signals through the resonant motions of the first and second driving electrodes. Therefore, since the signal generated by modulating a carrier signal through mechanical resonance according to the magnetic field is outputted, amplitude modulation can be carried out without a complicated circuit configuration. In addition, since an MEMS device is a single structure that does not include an insulating layer, a single signal is applied to one structure, thereby simplifying driving, and all the driving electrodes of both ends thereof are driven so as to double a change in variable capacitance, thereby improving sensing ability.

The present disclosure relates to a method and apparatus for setting the frequency of wireless power transmission. To this end, the method for setting the frequency of a wireless power transmission apparatus can include the steps of: obtaining power transmission information from the wireless power receiving apparatus receiving a wireless power signal; and setting the transmission frequency of the wireless power signal on the basis of the obtained power transmission information.

The present disclosure relates to a method and apparatus for setting the frequency of wireless power transmission. To this end, the method for setting the frequency of a wireless power transmission apparatus can include the steps of: obtaining power transmission information from the wireless power receiving apparatus receiving a wireless power signal; and setting the transmission frequency of the wireless power signal on the basis of the obtained power transmission information.

A method for switching interval modulation includes modulating an RF input data signal while generating and inserting additional pulses in transitions of the data signal. The additional pulses are structured to shift transition noise into higher order harmonics. Higher order harmonics are easily filtered. The generating is conducted in the digital domain. The additional pulses can be used to simplify the transmit chain through optical modulators and improve the signal integrity over long distances, can be applied at the output of a transmitter to filter power amplifier distortion, and can be appplied to non-linear RF over fiber for a distributed MIMO system.

A transmitter circuit includes a phase locked loop circuit, having one or more operational characteristics indicative of an operating state of the phase locked loop circuit. The phase locked loop circuit is configured to generate a frequency signal. The transmitter circuit also includes a power amplifier configured to selectively drive an antenna with a drive signal according to the frequency signal, and a programmable delay circuit configured to controllably extend a propagation delay between the frequency signal and the drive signal of the power amplifier. The programmable delay circuit is programmed such that a first value of a particular operational characteristic of the phase locked loop circuit is substantially equal to a second value of the operational characteristic of the phase locked loop circuit. The first value is measured with the power amplifier not driving the antenna. The second value is measured with the power amplifier driving the antenna.

Techniques are described for using valley detection for supply voltage modulation in power amplifier circuits. Embodiments operate in context of a power amplifier circuit configured to be driven by a supply voltage generated by a supply modulator and to receive an amplitude-modulated (AM) signal at its input. The output of the power amplifier circuit can be fed to a valley detector that can detect a valley level corresponding to the bottom of the envelope of the AM signal. The detected valley level can be fed back to the supply modulator and compared to a constant reference. In response to the comparison, the supply modulator can vary the supply voltage to the power amplifier circuit in a manner that effectively tracking the envelope of the power amplifier circuit's output signal, thereby effectively seeking a flat valley for the output signal's envelope.

A physiological signal detection system is disclosed. The physiological signal detection system includes a measurement module, a signal processing module, and a microcontroller. The measurement module measures a subject in a non-contact manner to obtain a frequency modulation signal. The signal processing module is electrically connected to the measurement module, and the signal processing module includes a Mohr discriminator, which is used to demodulate the frequency modulation signal to obtain a physiological signal. The microcontroller is electrically connected to the signal processing module for converting and obtaining a digital physiological signal.