Abstract: In certain aspects, a voltage controlled oscillator (VCO), a system circuit, and a control method thereof are disclosed. The VCO includes a first oscillator circuit and a second oscillator circuit. The first oscillator circuit includes a first inductor. The second oscillator circuit includes a second inductor. The first inductor is embedded inside the second inductor so that a total mutual inductance between the first and second inductors is smaller than or equal to a predetermined threshold.

Abstract: In certain aspects, a power amplification device, a power amplification system, and an operation method thereof are disclosed. The power amplification system includes a power amplification device and a control unit. The power amplification device includes a plurality of power amplification circuits, a power supply network configured to supply a power source from a plurality of power sources to the plurality of power amplification circuits, and a transformer network configured to provide an output power that matches a transmit power level. The control unit includes a memory storing code and a processor coupled to the memory. When the code is executed, the processor is configured to determine a plurality of circuit configurations for the plurality of power amplification circuits based on the transmit power level, and configure the plurality of power amplification circuits using the plurality of circuit configurations, respectively, so that the output power matches the transmit power level.

Abstract: Embodiments of systems and methods for transmission of audio information are disclosed herein. In one example, a System on Chip (SoC) includes a wired transceiver module, a wireless module, a Frequency Modulation (FM) demodulation module, and an audio information codec module operatively coupled to the wired transceiver and the FM demodulation module. The wired transceiver module is configured to receive a data packet corresponding to first audio information. The wireless module is configured to receive an FM signal, corresponding to second audio information. The FM demodulation module is configured to output the second audio information based on demodulating the FM signal. The audio information codec module is configured to decode the first audio information and the second audio information based on the data packet and the demodulated FM signal, respectively.

Abstract: Embodiments of systems and methods for transmission of audio information are disclosed herein. In one example, a System on Chip (SoC) includes a wired transceiver module, a wireless module, a Frequency Modulation (FM) demodulation module, and an audio information codec module operatively coupled to the wired transceiver and the FM demodulation module. The wired transceiver module is configured to receive a data packet corresponding to first audio information. The wireless module is configured to receive an FM signal, corresponding to second audio information. The FM demodulation module is configured to output the second audio information based on demodulating the FM signal. The audio information codec module is configured to decode the first audio information and the second audio information based on the data packet and the demodulated FM signal, respectively.

Abstract: Embodiments of circuits and methods for starting a crystal oscillator are disclosed herein. In one example, an oscillation circuit is disclosed. The oscillation circuit includes a multi-phase oscillator, a control circuit, a phase selection circuit, a drive circuit, and a crystal oscillator. The multi-phase oscillator is configured to generate candidate clock signals of multiple phases. The phase selection circuit is coupled to the multi-phase oscillator and configured to select a clock signal from the candidate clock signals. The drive circuit is coupled to the phase selection circuit and configured to inject the selected clock signal to the crystal oscillator for a period of time determined by the control circuit. The control circuit is coupled to the phase selection circuit and the drive circuit and is configured to control the on and off of the drive circuit and output a plurality of injections signals.

Abstract: Embodiments of oscillator circuits for wireless transmission of data are disclosed herein. In one example, an oscillator circuit includes an active network and a passive differential network coupled to the active network is disclosed. The active network is configured to generate an active signal for sustaining oscillation of the oscillator circuit. The passive network includes a first subnetwork, a second subnetwork, a first inductor and a second inductor. The first subnetwork is configured to adjust a central value of a resonant frequency of the oscillation. The passive network further includes a second subnetwork configured to further adjust the resonant frequency of the oscillation.

Abstract: Embodiments of systems and methods for clock synchronization for transmission of audio information are disclosed herein. In one example, a System on Chip (SoC) includes a Universal Serial Bus (USB) transceiver, an oscillator circuit free of a crystal, a frequency divider, and a clock synchronization calibrator. The USB transceiver is configured to extract a first synchronization clock associated with data received by the USB transceiver. The oscillator circuit free of a crystal is configured to generate an original clock. The frequency divider is configured to generate a second synchronization clock based on the original clock. The clock synchronization calibrator configured to generate a first set of frequency control data based on a frequency difference between the first synchronization clock and the second synchronization clock.

Abstract: Embodiments of systems and methods for clock synchronization for transmission of audio information are disclosed herein. In one example, a System on Chip (SoC) includes a Universal Serial Bus (USB) transceiver, an oscillator circuit free of a crystal, a frequency divider, and a clock synchronization calibrator. The USB transceiver is configured to extract a first synchronization clock associated with data received by the USB transceiver. The oscillator circuit free of a crystal is configured to generate an original clock. The frequency divider is configured to generate a second synchronization clock based on the original clock. The clock synchronization calibrator configured to generate a first set of frequency control data based on a frequency difference between the first synchronization clock and the second synchronization clock.

Abstract: Embodiments of voltage-controlled oscillators for wireless transmission of data are disclosed herein. In one example, an oscillator circuit includes an active network, a passive differential network coupled to the active network, and a tail tank connected to the active network through a low impedance point of the active network is disclosed. The active network is configured to generate an activating signal for sustaining oscillation of the oscillator circuit. The passive differential network has a first input impedance magnitude peak at a first frequency and a second input impedance magnitude peak at a second frequency. The tail tank circuit has a third input impedance magnitude peak at a third frequency.

Abstract: Embodiments of a system utilizing a human body for communication, a headset that uses a human body as a transmission medium, and a headset stereo playback method are disclosed. In an example, a system utilizing a human body for communication includes a processing chip, a signal emitting module and a signal receiving module connected with the processing chip, a signal receiving antenna connected to the signal receiving module, and a signal emitting electrode connected to the signal emitting module. The signal emitting electrode is separated from the signal receiving antenna. The signal emitting electrode and the signal receiving antenna are coupled to the human body for emitting a signal to the human body and receiving a signal from the human body.

Abstract: Embodiments of a system utilizing a human body for communication, a headset that uses a human body as a transmission medium, and a headset stereo playback method are disclosed. In an example, a system utilizing a human body for communication includes a processing chip, a signal emitting module and a signal receiving module connected with the processing chip, a signal receiving antenna connected to the signal receiving module, and a signal emitting electrode connected to the signal emitting module. The signal emitting electrode is separated from the signal receiving antenna. The signal emitting electrode and the signal receiving antenna are coupled to the human body for emitting a signal to the human body and receiving a signal from the human body.