Abstract: A portable electronic device includes an antenna unit, a processor, a circuit board and a frequency switching circuit. The antenna unit includes a pin. The processor includes a signal control terminal to output a voltage control signal. The frequency switching circuit is disposed on the circuit board and connected to the signal control terminal and the pin, so as to switch the frequency of the antenna unit according to the voltage control signal. The frequency switching circuit includes a switch unit and an anti-noise unit. The switch unit is connected to the pin, and the anti-noise unit is connected to the signal control terminal and the switch unit.

Abstract: A portable electronic device includes an antenna unit, a processor, a circuit board and a frequency switching circuit. The antenna unit includes a pin. The processor includes a signal control terminal to output a voltage control signal. The frequency switching circuit is disposed on the circuit board and connected to the signal control terminal and the pin, so as to switch the frequency of the antenna unit according to the voltage control signal. The frequency switching circuit includes a switch unit and an anti-noise unit. The switch unit is connected to the pin, and the anti-noise unit is connected to the signal control terminal and the switch unit.

Abstract: A communication device having a wireless communication system and a Near Field Communication (NFC) circuit is provided. The NFC circuit includes two pads, two ferrite beads and a NFC controller. The first pad and the second pad are coupled to a NFC antenna. The first and the second ferrite bead are respectively coupled to the first pad and the second pad. The NFC controller includes two pins. The first pin and the second pin are coupled to the first ferrite bead and the second ferrite bead, respectively. The first pin and the second pin output a differential NFC signal to be emitted by the NFC antenna. The first and the second ferrite bead allow the fundamental frequency component of the NFC signal to pass, and filter out a plurality of high-frequency components for avoiding the operating frequency of the wireless communication system from being interfered by the high-frequency components.

Abstract: A handheld electronic apparatus and operation methods thereof are provided. The handheld electronic apparatus includes a button, a processor, and a sensor. The button is configured to generate an interrupt signal when being triggered. The processor is electrically connected to the button and configured to generate an event signal in response to the interrupt signal. The sensor is electrically connected to the processor, and configured to be turned on in response to the event signal and generate a sensed signal. The processor is further configured to generate a comparison result by comparing the sensed signal with a threshold, and determine whether the button is triggered intentionally or accidentally according to the comparison result.

Abstract: A communication device having a wireless communication system and a Near Field Communication (NFC) circuit is provided. The NFC circuit includes two pads, two ferrite beads and a NFC controller. The first pad and the second pad are coupled to a NFC antenna. The first and the second ferrite bead are respectively coupled to the first pad and the second pad. The NFC controller includes two pins. The first pin and the second pin are coupled to the first ferrite bead and the second ferrite bead, respectively. The first pin and the second pin output a differential NFC signal to be emitted by the NFC antenna. The first and the second ferrite bead allow the fundamental frequency component of the NFC signal to pass, and filter out a plurality of high-frequency components for avoiding the operating frequency of the wireless communication system from being interfered by the high-frequency components.