An antenna system includes a dielectric substrate, a ground element, and a first antenna element. The dielectric substrate has a first surface and a second surface, which are opposite to each other. The ground element is disposed on the first surface of the dielectric substrate. The first antenna element includes a first radiation element, a feeding radiation element, a second radiation element, and a shorting radiation element. The first radiation element has a feeding point, and is disposed on the second surface of the dielectric substrate. The feeding radiation element is adjacent to the first radiation element. The second radiation element is coupled to the feeding radiation element. The second radiation element is further coupled through the shorting radiation element to the ground element.

A phase-shift unit includes: a first substrate and a second substrate provided opposite to each other; a medium layer provided between the first substrate and the second substrate; a microstrip line disposed at a side of the second substrate facing towards the first substrate; and a grounding layer provided at a side of the first substrate facing towards the second substrate and formed with a via hole; wherein a projection of the via hole onto the second substrate and a projection of the microstrip line onto the second substrate have an overlapped area therebetween; and wherein the via hole is configured to feed a phase-shifted microwave signal out of the phase-shift unit, or feed a microwave signal into the phase-shift unit such that the microwave signal is phase-shifted.

A phase-shift unit includes: a first substrate and a second substrate provided opposite to each other; a medium layer provided between the first substrate and the second substrate; a microstrip line disposed at a side of the second substrate facing towards the first substrate; and a grounding layer provided at a side of the first substrate facing towards the second substrate and formed with a via hole; wherein a projection of the via hole onto the second substrate and a projection of the microstrip line onto the second substrate have an overlapped area therebetween; and wherein the via hole is configured to feed a phase-shifted microwave signal out of the phase-shift unit, or feed a microwave signal into the phase-shift unit such that the microwave signal is phase-shifted.

An eyewear device has an antenna system having at least one element which contributes to wireless signal transmission, and which is thermally connected to a heat-generating electronic component of the eyewear device to serve as a heat sink for the electronic component. A driven antenna element and/or a plurality of PCB extenders electrically connected to a PCB ground plane can thus be employed for both signal transmission and heat management.

An eyewear device has an antenna system having at least one element which contributes to wireless signal transmission, and which is thermally connected to a heat-generating electronic component of the eyewear device to serve as a heat sink for the electronic component. A driven antenna element and/or a plurality of PCB extenders electrically connected to a PCB ground plane can thus be employed for both signal transmission and heat management.

The insertion loss of a multilayer substrate and an antenna element is reduced. A multilayer substrate according to an embodiment of the present disclosure includes a multilayer body, a wire conductor, and a first ground electrode. The multilayer body is formed by dielectric layers being layered. The wire conductor is formed in the multilayer body, and a radio frequency signal passes through the wire conductor. The first ground electrode is formed in or on the multilayer body and includes a first surface that faces the wire conductor. The first surface includes a first region and a second region. The surface roughness of the first region is lower than the surface roughness of the second region. The first region overlaps at least part of the wire conductor in plan view in a direction normal to the first ground electrode.

Provided is an antenna device with a simple configuration, said antenna device supporting a plurality of frequency bands. An antenna device according to the present invention is provided with: at least one first radiation element that has a resonant frequency in a first frequency band; at least one second radiation element; and a connection line for connecting the first radiation element and the second radiation element. The line length formed of the first radiation element, the connection line, and the second radiation element is set to a length so as to have a resonant frequency in a second frequency band lower than the first frequency band.

Provided is an antenna device with a simple configuration, said antenna device supporting a plurality of frequency bands. An antenna device according to the present invention is provided with: at least one first radiation element that has a resonant frequency in a first frequency band; at least one second radiation element; and a connection line for connecting the first radiation element and the second radiation element. The line length formed of the first radiation element, the connection line, and the second radiation element is set to a length so as to have a resonant frequency in a second frequency band lower than the first frequency band.

An antenna includes: a first antenna portion and a second antenna portion arranged adjacently. The first antenna portion includes a first antenna branch and a first parasitic branch, and the second antenna portion includes a second antenna branch. The first parasitic branch is positioned between the first antenna branch and the second antenna branch. The first parasitic branch is L-shaped, and includes a first branch segment and a second branch segment. A first end of the first branch segment is in contact to a ground region, a second end of the first branch segment is joined to a first end of the second branch segment, and a second end of the second branch segment points towards the second antenna branch.

An antenna includes: a first antenna portion and a second antenna portion arranged adjacently. The first antenna portion includes a first antenna branch and a first parasitic branch, and the second antenna portion includes a second antenna branch. The first parasitic branch is positioned between the first antenna branch and the second antenna branch. The first parasitic branch is L-shaped, and includes a first branch segment and a second branch segment. A first end of the first branch segment is in contact to a ground region, a second end of the first branch segment is joined to a first end of the second branch segment, and a second end of the second branch segment points towards the second antenna branch.