Abstract: An antenna device includes first antenna units, second antenna units, first switching circuits and second switching circuits. The first antenna units generate radio frequency (RF) signals operating at a first frequency. The second antenna units generate RF signals operating at a second frequency. The first frequency is larger than the second frequency. The first switching circuits selectively enable at least one of the first antenna units. Each of the first switching circuits includes a first switch element and a second switch element. The first switch element is connected in parallel with an inductor. The second switch element is connected in parallel with another inductor. The second switching circuits selectively enable at least one of the second antenna units.

Abstract: An antenna structure includes an antenna pattern, a ground layer and two microstrip lines. The antenna pattern includes a first portion and a second portion. The first portion is rectangle shape and includes a first, a second, a third and a fourth sides. The second portion protrudes outwardly from the first side and the second side. The ground layer has two slots. Projections of the two slots to the antenna pattern are close to the third and the fourth sides. Projections of the two microstrip lines to the antenna pattern are perpendicular to the third and the fourth sides. Each microstrip line has a first section and a second section. Projection of the second section to the antenna pattern is closer to a center of the first portion than projection of the first section. A width of the first section is greater than a width of the second section.

Abstract: An antenna device includes antenna units, transmission lines and switching circuits. The antenna units are used to be operated in a directional mode or an omni-directional mode. The transmission lines are coupled to the antenna units. The switching circuits are coupled to the respective transmission lines, and are used for selectively connecting the transmission lines according to control signals. At least one transmission line is disconnected when the antenna units are operated in the directional mode. All the transmission lines are connected when the antenna units are operated in the omni-directional mode.

Abstract: A dual-band antenna module includes a substrate, a dual-band omnidirectional antenna, a low-frequency reflection module and a high-frequency reflection module. The dual-band omnidirectional antenna is disposed perpendicular to the substrate and is used for resonating to generate a first radio-frequency signal with a first frequency and a second radio-frequency signal with a second frequency. The low-frequency reflection module includes three low-frequency reflection units used for reflecting the first radio-frequency signal with the first frequency according to different low-frequency directional control signals. The high-frequency reflection module includes three high-frequency reflection units used for reflecting the second radio-frequency signal with the second frequency according to different high-frequency directional control signals.

Abstract: An antenna structure includes an antenna pattern, a ground layer and two microstrip lines. The antenna pattern includes a first portion and a second portion. The first portion is rectangle shape and includes a first, a second, a third and a fourth sides. The second portion protrudes outwardly from the first side and the second side. The ground layer has two slots. Projections of the two slots to the antenna pattern are close to the third and the fourth sides. Projections of the two microstrip lines to the antenna pattern are perpendicular to the third and the fourth sides. Each microstrip line has a first section and a second section. Projection of the second section to the antenna pattern is closer to a center of the first portion than projection of the first section. A width of the first section is greater than a width of the second section.

Abstract: An antenna device includes first antenna units, second antenna units, first switching circuits and second switching circuits. The first antenna units generate radio frequency (RF) signals operating at a first frequency. The second antenna units generate RF signals operating at a second frequency. The first frequency is larger than the second frequency. The first switching circuits selectively enable at least one of the first antenna units. Each of the first switching circuits includes a first switch element and a second switch element. The first switch element is connected in parallel with an inductor. The second switch element is connected in parallel with another inductor. The second switching circuits selectively enable at least one of the second antenna units.

Abstract: A dual-band antenna module includes a substrate, a dual-band omnidirectional antenna, a low-frequency reflection module and a high-frequency reflection module. The dual-band omnidirectional antenna is disposed perpendicular to the substrate and is used for resonating to generate a first radio-frequency signal with a first frequency and a second radio-frequency signal with a second frequency. The low-frequency reflection module includes three low-frequency reflection units used for reflecting the first radio-frequency signal with the first frequency according to different low-frequency directional control signals. The high-frequency reflection module includes three high-frequency reflection units used for reflecting the second radio-frequency signal with the second frequency according to different high-frequency directional control signals.

Abstract: An antenna device includes antenna units, transmission lines and switching circuits. The antenna units are used to be operated in a directional mode or an omni-directional mode. The transmission lines are coupled to the antenna units. The switching circuits are coupled to the respective transmission lines, and are used for selectively connecting the transmission lines according to control signals. At least one transmission line is disconnected when the antenna units are operated in the directional mode. All the transmission lines are connected when the antenna units are operated in the omni-directional mode.

Abstract: An antenna device includes a dual-band cross dipole antenna including four radiators each extending from an axis toward a plane and including a first radiating element and a second radiating element for transmitting or receiving radio signals of a first band and a second band, wherein a plane where each radiator is located is perpendicular to a plane where a neighboring radiator is located; and a reflecting board disposed on a side of the dual-band cross dipole antenna, wherein a location and a shape of the reflecting board relate to wavelengths corresponding to signals of the first band and the second band, such that the dual-band cross dipole antenna is directional in the first band and omnidirectional in the second band.

Abstract: An antenna device includes a first dipole antenna and a second dipole antenna. The polarization direction of the first dipole antenna is a first direction, and the polarization direction of the second dipole antenna is the first direction. Each of the first dipole antenna and the second dipole antenna includes at least one first radiator and at least one second radiator, and there is a notch between the first and second radiators. The notch of the first dipole antenna is towards a second direction, and the notch of the second dipole antenna is toward a third direction that is different from the second direction.

Abstract: A smart antenna module includes an omni-directional antenna and at least one reflecting unit for adjusting a radiation pattern of the smart antenna module, wherein the one reflecting unit includes a reflector and a switch coupled between the reflector and a ground of the omni-directional antenna for electrically connecting the reflector with the ground or separating the reflector from the ground according to a control signal to adjust the radiation pattern of the smart antenna module.

Abstract: An antenna device includes a first dipole antenna and a second dipole antenna. The polarization direction of the first dipole antenna is a first direction, and the polarization direction of the second dipole antenna is the first direction. Each of the first dipole antenna and the second dipole antenna includes at least one first radiator and at least one second radiator, and there is a notch between the first and second radiators. The notch of the first dipole antenna is towards a second direction, and the notch of the second dipole antenna is toward a third direction that is different from the second direction.

Abstract: An antenna device includes a dual-band cross dipole antenna including four radiators each extending from an axis toward a plane and including a first radiating element and a second radiating element for transmitting or receiving radio signals of a first band and a second band, wherein a plane where each radiator is located is perpendicular to a plane where a neighboring radiator is located; and a reflecting board disposed on a side of the dual-band cross dipole antenna, wherein a location and a shape of the reflecting board relate to wavelengths corresponding to signals of the first band and the second band, such that the dual-band cross dipole antenna is directional in the first band and omnidirectional in the second band.

Abstract: A smart antenna module includes an omni-directional antenna and at least one reflecting unit for adjusting a radiation pattern of the smart antenna module, wherein the one reflecting unit includes a reflector and a switch coupled between the reflector and a ground of the omni-directional antenna for electrically connecting the reflector with the ground or separating the reflector from the ground according to a control signal to adjust the radiation pattern of the smart antenna module.

Abstract: A radio-frequency transceiver system adapted to a wireless local area network includes an antenna set, including a plurality of antenna units disposed toward a plurality of directions, a radio-frequency signal processing module for processing radio-frequency signals, and a switching module electrically coupled between the antenna set and the radio-frequency signal processing module for switching between different connection states of the radio-frequency signal processing module and the antenna units of the antenna set such that the radio-frequency transceiver system switches between an omnidirectional mode and a directional mode. In the omnidirectional mode, the antenna units are electrically connected to the radio-frequency signal processing module to transmit or receive radio-frequency signals omni-directionally.