Examples of antennas to reduce specific absorption rate (SAR) are described herein. In some examples, an antenna may include a metal structure with an open slot and a closed slot. A first radiator trace may be positioned to overlap a portion of the open slot. A second radiator trace may be positioned to overlap a portion of the closed slot. A matching network may pass a low frequency band to the first radiator trace and may pass a high frequency band to the second radiator trace.

An antenna (100) for emitting radiation from at least one electromagnetic traveling wave which propagates along a guide path is designed to reduce reflection of the traveling wave likely to occur at the end of the guide path. To this purpose, the guide path has at least one portion in the form of a spiral segment (11, 12), which is connected to another portion of the guide path in the form of a loop (13). Gain in the antenna's reflection coefficient can be obtained in this manner, which is effective in particular near a lower frequency limit of a transmission band of the antenna.

An antenna (100) for emitting radiation from at least one electromagnetic traveling wave which propagates along a guide path is designed to reduce reflection of the traveling wave likely to occur at the end of the guide path. To this purpose, the guide path has at least one portion in the form of a spiral segment (11, 12), which is connected to another portion of the guide path in the form of a loop (13). Gain in the antenna's reflection coefficient can be obtained in this manner, which is effective in particular near a lower frequency limit of a transmission band of the antenna.

A patch antenna intended to equip a spacecraft, the antenna comprising a dielectric substrate, a radiating antenna element present on the dielectric substrate, the radiating antenna element having a center of symmetry and an area devoid of material, the center of symmetry being present in the area devoid of material, and a protective layer covering the radiating antenna element.

An electromagnetic tool using slotted dipole antennas is presented. The dipoles may be placed in slots on a drill collar. A receiver or transmitter antenna consists of one or more slots. A dipole consists of a ferrite rod with electric wires placed above and below the ferrite. Wires may be connected such that wire current forms a loop around the ferrite rod. When a group of slots are used for an antenna, wire holes are constructed between slots. Effectively a single wire may be used to go above all ferrite rods in the group and then turn to go below all the rods. Two wire segments are in a wire hole connecting two adjacent slots. Currents in the two segments are the same in magnitudes and flow in opposite directions. There is no net current in wires in a wire hole.

A patch antenna includes a dielectric substrate formed by a high dielectric coefficient material covered with a soft material. The dielectric substrate has a first surface, an opposite second surface, and surrounding side surfaces there between. The patch antenna further includes a radiating metal arm formed on at least the first surface with a thin metal layer in a specific shape, a grounding metal plate disposed on the second surface, and a parasitic metal arm extending from the grounding metal plate towards the first surface via at least one of the side surfaces. The parasitic metal arm is approximate but not connected to the radiating metal arm. The radiation metal arm further includes an enclosed slot, together with the parasitic metal arm, improve the working bandwidth and high directivity of the antenna.

A patch antenna includes a dielectric substrate formed by a high dielectric coefficient material covered with a soft material. The dielectric substrate has a first surface, an opposite second surface, and surrounding side surfaces there between. The patch antenna further includes a radiating metal arm formed on at least the first surface with a thin metal layer in a specific shape, a grounding metal plate disposed on the second surface, and a parasitic metal arm extending from the grounding metal plate towards the first surface via at least one of the side surfaces. The parasitic metal arm is approximate but not connected to the radiating metal arm. The radiation metal arm further includes an enclosed slot, together with the parasitic metal arm, improve the working bandwidth and high directivity of the antenna.

A reflector structure is configured to connect an antenna. The antenna has an excitation source. The reflector structure includes a metal substrate, at least one first flat plate and a second flat plate. The metal substrate is configured to reflect the radiation of the antenna. The at least one first flat plate is disposed on the metal substrate. The second flat plate is floated to the metal substrate along a virtual normal and completely separated from the at least one first flat plate to form a closed slot. A cavity is formed by the metal substrate, the at least one first flat plate and the second flat plate and communicated with the closed slot. The excitation source is projected onto a plane to form an excitation source region. The excitation source region is located in the second flat plate.

Eyewear with a slot ring antenna generating E-fields that are orthogonal to each other at a frequency. The slot ring antenna has a first portion including an inner ring and an outer ring configured to generate a first E-field in a first direction, and a second portion having a respective inner ring and the outer right configured to generate a second E-field in a second direction that is orthogonal to the first E-field. The outer ring encompasses the respective inner rings, where a first slot is defined between the respective inner ring and the outer ring. A second slot is encompassed by the respective inner ring, and it may be a cutout. The slot ring antenna encompasses eyewear optical assemblies. In one example, the slot antenna first portion encompasses a first optical assembly, and the second portion encompasses the second optical assembly. The outer ring may comprise of a common ground plane, which ground plane may extend proximate a bridge of the eyewear. The two portions of the antenna co-exist in very close proximity to each other and support the same frequency band with minimal coupling to each other due to the orthogonal E-fields.

Eyewear with a slot ring antenna generating E-fields that are orthogonal to each other at a frequency. The slot ring antenna has a first portion including an inner ring and an outer ring configured to generate a first E-field in a first direction, and a second portion having a respective inner ring and the outer right configured to generate a second E-field in a second direction that is orthogonal to the first E-field. The outer ring encompasses the respective inner rings, where a first slot is defined between the respective inner ring and the outer ring. A second slot is encompassed by the respective inner ring, and it may be a cutout. The slot ring antenna encompasses eyewear optical assemblies. In one example, the slot antenna first portion encompasses a first optical assembly, and the second portion encompasses the second optical assembly. The outer ring may comprise of a common ground plane, which ground plane may extend proximate a bridge of the eyewear. The two portions of the antenna co-exist in very close proximity to each other and support the same frequency band with minimal coupling to each other due to the orthogonal E-fields.