An antenna structure includes a border frame, a first feed portion, a second feed portion, and two ground portions. The border frame includes a first gap and a second gap passing through the border frame, thereby defining a first radiating portion and a second radiating portion. The first feed portion is electrically coupled to the first radiating portion to supply an electric current to the first radiating portion. The second feed portion is electrically coupled to the second radiating portion to supply an electric current to the second radiating portion. The two ground portions are disposed between the first feed portion and the second feed portion and separated from each other. The two ground portions are electrically coupled to the first radiating portion or the second radiating portion.

In examples, systems and methods for increasing the performance of electrically-small antennas are described. An example system comprises an electrically-small antenna having an antenna feed. The electrically-small antenna is configured to receive a signal. The system also comprises a non-foster circuit having a negative capacitance coupled to the antenna feed in a shunt position. The non-foster circuit is configured to resonate the electrically-small antenna and provide a voltage increase to the received signal. The system also comprises a buffer circuit configured to provide an impedance conversion of the voltage-increased received signal between the antenna feed and an output of the buffer circuit. The buffer circuit includes a field-effect transistor.

The wireless communication device has a first radiation element, which includes a first line path being extended between a first end and a second end and performs communication at a first frequency. The device also has a second radiating element coupled to the first radiating element and resonating at a second frequency, which element has a second line path extending from a first connecting portion connected to the sheet metal to a third end portion near the first end portion, and a third path line extending from an intermediate point between the first connecting portion and the third end portion to the fourth end portion. And a power supply circuit for a third frequency is connected to the fourth end via a cutoff circuit which cuts off the second frequency. With this configuration, the wireless communication device enables the communication in more frequency bands.

The wireless communication device has a first radiation element, which includes a first line path being extended between a first end and a second end and performs communication at a first frequency. The device also has a second radiating element coupled to the first radiating element and resonating at a second frequency, which element has a second line path extending from a first connecting portion connected to the sheet metal to a third end portion near the first end portion, and a third path line extending from an intermediate point between the first connecting portion and the third end portion to the fourth end portion. And a power supply circuit for a third frequency is connected to the fourth end via a cutoff circuit which cuts off the second frequency. With this configuration, the wireless communication device enables the communication in more frequency bands.

A wireless handheld or portable device includes an antenna system operable in a first frequency region and a higher, second frequency region. The antenna system comprises an antenna structure, a matching and tuning system, and an external input/output (I/O) port. The antenna structure comprises at least one radiating element including a connection point, a ground plane layer including at least one connection point, and at least one internal I/O port. At least one radiating element of the antenna structure protrudes beyond the ground plane layer. The antenna structure features at any of its internal I/O ports when disconnected from the matching and tuning system an input return loss curve having a minimum at a frequency outside the first frequency region of the antenna system. The matching and tuning system modifies the impedance of the antenna structure and provides impedance matching to the antenna system in the first and second regions.

A wireless handheld or portable device includes an antenna system operable in a first frequency region and a higher, second frequency region. The antenna system comprises an antenna structure, a matching and tuning system, and an external input/output (I/O) port. The antenna structure comprises at least one radiating element including a connection point, a ground plane layer including at least one connection point, and at least one internal I/O port. At least one radiating element of the antenna structure protrudes beyond the ground plane layer. The antenna structure features at any of its internal I/O ports when disconnected from the matching and tuning system an input return loss curve having a minimum at a frequency outside the first frequency region of the antenna system. The matching and tuning system modifies the impedance of the antenna structure and provides impedance matching to the antenna system in the first and second regions.

The present disclosure provides an antenna system of a mobile terminal. The mobile terminal includes a housing, a mainboard accommodated in the housing, a plastic holder covering the mainboard, and a USB interface installed on the mainboard. The antenna system includes a radiator formed on a surface of the plastic holder facing the housing, and a feed end, a first ground point and a second ground point that are disposed on the mainboard. The radiator includes a feed end and a ground feed end spaced apart from each other, a connection end connecting the feed end and the ground feed end, a first stub connected to the ground feed end, and a second stub and a third stub connected to the feed end. The antenna system provided by the present disclosure is more space-saving, and reduces the impact of the USB interface on the antenna.

The present disclosure provides an antenna system of a mobile terminal. The mobile terminal includes a housing, a mainboard accommodated in the housing, a plastic holder covering the mainboard, and a USB interface installed on the mainboard. The antenna system includes a radiator formed on a surface of the plastic holder facing the housing, and a feed end, a first ground point and a second ground point that are disposed on the mainboard. The radiator includes a feed end and a ground feed end spaced apart from each other, a connection end connecting the feed end and the ground feed end, a first stub connected to the ground feed end, and a second stub and a third stub connected to the feed end. The antenna system provided by the present disclosure is more space-saving, and reduces the impact of the USB interface on the antenna.

An electronic device such as a wristwatch may have a housing with metal sidewalls and a display having conductive display structures. The display structures may be separated from the sidewalls by a slot for an antenna that runs around the display module. A conductive interconnect may be coupled between the sidewalls and the display structures. A feed and tuning element may be coupled between the display structures and the sidewalls. A first length of the slot from the interconnect to the tuning element may radiate in a satellite band and a cellular band. A second length of the slot from the interconnect to the feed may radiate in a 2.4 GHz band. Harmonics of the second length may radiate in bands at and above 5.0 GHz. If desired clip and blade structures may form conductive paths for coupling antenna elements.

The dual-band antenna device includes: a feeding electrode that branches into a first branch feeding electrode that serves as a low-frequency signal path and a second branch feeding electrode that serves as a high-frequency signal path; and a radiation electrode having a rectangular shape with a longitudinal direction and having a low-frequency feeding point to which the first branch feeding electrode is electrically connected and a high-frequency feeding point to which the second branch feeding electrode is electrically connected. In the radiation electrode, the low-frequency feeding point or the high-frequency feeding point is formed close to an end portion of the rectangular shape in the longitudinal direction, and the high-frequency feeding point or the low-frequency feeding point is formed at a center portion of a side of the rectangular shape that extends in the longitudinal direction.