Abstract: The present application provides a transmission structure of an antenna and a proximity sensing circuit. The transmission structure includes a transmission line and at least one radio-frequency short-circuit element, a first coupling end of the transmission line is coupled to an antenna, and a second coupling end of the transmission line is coupled to a proximity sensing circuit, and the at least one radio-frequency short-circuit element is coupled between the transmission line and a ground, and is located between the antenna and the proximity sensing circuit. Utilizing the at least one radio-frequency short-circuit element in conjunction with the transmission line so that the transmission path between the antenna and the proximity sensing circuit has the high impedance, and hence preventing a radio-frequency signal from the antenna from affecting the sensing accuracy of the proximity sensing circuit.

Abstract: The present application provides a transmission structure of an antenna and a proximity sensing circuit. The transmission structure includes a transmission line and at least one radio-frequency short-circuit element, a first coupling end of the transmission line is coupled to an antenna, and a second coupling end of the transmission line is coupled to a proximity sensing circuit, and the at least one radio-frequency short-circuit element is coupled between the transmission line and a ground, and is located between the antenna and the proximity sensing circuit. Utilizing the at least one radio-frequency short-circuit element in conjunction with the transmission line so that the transmission path between the antenna and the proximity sensing circuit has the high impedance, and hence preventing a radio-frequency signal from the antenna from affecting the sensing accuracy of the proximity sensing circuit.

Abstract: An antenna switching system is provided. The system includes a radio frequency (RF) circuit for transmitting and receiving signals, a first antenna, a second antenna, a first switch, a first switch assembly, a second switch assembly, and a power divider. The first switch electrically connected to the RF circuit. The first switch assembly electrically connected between the first switch and the first antenna. The second switch assembly electrically connected between the first switch and the second antenna. The power divider electrically connected between the first switch and the first switch assembly and between the first switch and the second switch assembly. When the first switch is switched to the power divider, the signals are transmitted by the first antenna and the second antenna.

Abstract: An antenna switching system is provided. The system includes a radio frequency (RF) circuit for transmitting and receiving signals, a first antenna, a second antenna, a first switch, a first switch assembly, a second switch assembly, and a power divider. The first switch electrically connected to the RF circuit. The first switch assembly electrically connected between the first switch and the first antenna. The second switch assembly electrically connected between the first switch and the second antenna. The power divider electrically connected between the first switch and the first switch assembly and between the first switch and the second switch assembly. When the first switch is switched to the power divider, the signals are transmitted by the first antenna and the second antenna.

Abstract: A wireless communication device includes a first antenna, a second antenna, a first switching circuit, and a first tunable matching circuit. The first switching circuit is electrically connected to the first antenna, the second antenna, and the first tunable matching circuit. In a first operation mode, the first antenna of the wireless communication device performs signal transmission or reception, an impedance value corresponding to the first tunable matching circuit is adjusted to a first impedance value, and the second antenna is conducted to the first tunable matching circuit through the first switching circuit. In a second operation mode, the second antenna of the wireless communication device performs signal transmission or reception, the impedance value corresponding to the first tunable matching circuit is adjusted to a second impedance value, and the first antenna is conducted to the first tunable matching circuit through the first switching circuit.

Abstract: An antenna switching system is provided. The system includes a radio frequency (RF) circuit for transceiving signals, N antennas, a master switch, N switches, and N power dividers. The signals may be transmitted by one of the N antennas, or the signals are transmitted by the antennas of the N antennas.

Abstract: A wireless communication device includes a first antenna, a second antenna, a first switching circuit, and a first tunable matching circuit. The first switching circuit is electrically connected to the first antenna, the second antenna, and the first tunable matching circuit. In a first operation mode, the first antenna of the wireless communication device performs signal transmission or reception, an impedance value corresponding to the first tunable matching circuit is adjusted to a first impedance value, and the second antenna is conducted to the first tunable matching circuit through the first switching circuit. In a second operation mode, the second antenna of the wireless communication device performs signal transmission or reception, the impedance value corresponding to the first tunable matching circuit is adjusted to a second impedance value, and the first antenna is conducted to the first tunable matching circuit through the first switching circuit.

Abstract: A wireless communication apparatus and a method for improving specific absorption ration thereof are provided. The method includes following steps. A first signal quality parameter of a first antenna and a second signal quality parameter of a second antenna are obtained. A first amplifier character parameter of a power amplifier while the power amplifier is connected to the first antenna is predicted, and a second amplifier character parameter of the power amplifier while the power amplifier is connected to the second antenna is predicted. The first antenna or the second antenna is selected to transmit a RF transmission signal according to the first amplifier character parameter, the first signal quality parameter, the second amplifier character parameter and the second signal quality parameter.

Abstract: A wireless communication apparatus and a method for improving specific absorption ration thereof are provided. The method includes following steps. A first signal quality parameter of a first antenna and a second signal quality parameter of a second antenna are obtained. A first amplifier character parameter of a power amplifier while the power amplifier is connected to the first antenna is predicted, and a second amplifier character parameter of the power amplifier while the power amplifier is connected to the second antenna is predicted. The first antenna or the second antenna is selected to transmit a RF transmission signal according to the first amplifier character parameter, the first signal quality parameter, the second amplifier character parameter and the second signal quality parameter.

Abstract: A tunable impedance matching circuit is provided for matching a signal source to an impedance of an antenna. The tunable impedance matching circuit includes two terminals, a series path, and two shunt paths. The first terminal is coupled to the signal source, and the second terminal is coupled to the antenna. The series path is coupled between the first terminal and the second terminal and includes a first tunable capacitor and at least one tunable inductor. One of the two shunt paths is coupled between the first terminal and a ground end, and the other one of the two shunt paths is coupled between the second terminal and the ground end. Each of the shunt paths includes a second tunable capacitor.

Abstract: An electronic device includes an antenna, an RF circuit, and a matching circuit. The matching circuit is configured to provide variable impedance between the antenna and the RF circuit, wherein the matching circuit includes a first element having a first terminal and a second terminal, and wherein the first terminal is coupled to the antenna; a second element having a third terminal connected to the second terminal of the first element and a fourth terminal coupled to the RF circuit; a first tuning cell connected to the second terminal of the first element and the third terminal of the second element, and comprising a first tuning element, a second tuning element and a first control element, wherein the first control element determines whether to make a first node connected between the first and second tuning elements couple to a voltage level.

Abstract: A portable communication device and an adjustable antenna thereof are disclosed herein. The portable communication device includes a substrate, the adjustable antenna and a control circuit. The adjustable antenna includes an antenna body, an adjusting element, a feeding terminal and a ground terminal. The antenna body has multiple conductive portions and is disposed above the substrate. The adjusting element is coupled between the conductive portions. The feeding terminal and the ground terminal extend from the antenna body and are coupled to the substrate. The control circuit feeds a first control signal and a second control signal respectively through the feeding terminal and the ground terminal to the adjusting element, so as to adjust an electrical length of the adjustable antenna.

Abstract: A portable communication device and an adjustable antenna thereof are disclosed herein. The portable communication device includes a substrate, the adjustable antenna and a control circuit. The adjustable antenna includes an antenna body, an adjusting element, a feeding terminal and a ground terminal. The antenna body has multiple conductive portions and is disposed above the substrate. The adjusting element is coupled between the conductive portions. The feeding terminal and the ground terminal extend from the antenna body and are coupled to the substrate. The control circuit feeds a first control signal and a second control signal respectively through the feeding terminal and the ground terminal to the adjusting element, so as to adjust an electrical length of the adjustable antenna.

Abstract: An electronic device for processing radio frequency signals includes an antenna, an RF circuit, and a matching circuit. The matching circuit provides variable impedance between the antenna and the RF circuit. The antenna is capable of operating in a first frequency band or a second frequency band according to the variable impedance The matching circuit includes a first element; a second element; a first tuning cell connected to the first element and the second element, and comprising a first tuning element, a second tuning element and a first control element, the first control element determining whether to make a first node connected between the first and second tuning elements couple to a voltage level according to a first control signal; and a selecting circuit coupled to the first control element and configured to generate the first control signal so as to adjust the variable impedance.

Abstract: A tunable impedance matching circuit is provided for matching a signal source to an impedance of an antenna. The tunable impedance matching circuit includes two terminals, a series path, and two shunt paths. The first terminal is coupled to the signal source, and the second terminal is coupled to the antenna. The series path is coupled between the first terminal and the second terminal and includes a first tunable capacitor and at least one tunable inductor. One of the two shunt paths is coupled between the first terminal and a ground end, and the other one of the two shunt paths is coupled between the second terminal and the ground end. Each of the shunt paths includes a second tunable capacitor.

Abstract: An electronic device for processing radio frequency signals includes an antenna, an RF circuit, and a matching circuit. The matching circuit provides variable impedance between the antenna and the RF circuit. The antenna is capable of operating in a first frequency band or a second frequency band according to the variable impedance The matching circuit includes a first element; a second element; a first tuning cell connected to the first element and the second element, and comprising a first tuning element, a second tuning element and a first control element, the first control element determining whether to make a first node connected between the first and second tuning elements couple to a voltage level according to a first control signal; and a selecting circuit coupled to the first control element and configured to generate the first control signal so as to adjust the variable impedance.

Abstract: An electronic device includes an antenna, an RF circuit, and a matching circuit. The matching circuit is configured to provide variable impedance between the antenna and the RF circuit, wherein the matching circuit includes a first element having a first terminal and a second terminal, and wherein the first terminal is coupled to the antenna; a second element having a third terminal connected to the second terminal of the first element and a fourth terminal coupled to the RF circuit; a first tuning cell connected to the second terminal of the first element and the third terminal of the second element, and comprising a first tuning element, a second tuning element and a first control element, wherein the first control element determines whether to make a first node connected between the first and second tuning elements couple to a voltage level.

Abstract: The dual-band monopole printed antenna of this invention comprises: a monopole printed antenna body to perform resonance in response to a first frequency, with one end of the body connected to feed-in line; a tail; and a short-circuited transmission line connecting the other end of the antenna body and an end of the tail; wherein the short-circuited transmission line forms open circuit at its connection with said antenna body when supplied with a current of the first frequency and wherein the antenna body, the transmission line and the tail together perform resonance in response to a second frequency.