A slot array antenna including a smooth curved surface and planar feed structures which are respectively disposed at two ends of the smooth curved surface and are tangent to the smooth curved surface. The smooth curved surface includes at least two arcs mutually connected by smooth transition. The at least two arcs each includes an upper copper metal layer, a lower copper metal layer, and a dielectric substrate layer between the upper and lower copper metal layers. The upper copper metal layer includes radiating slots, and the adjacent radiating slots in a linear array have opposite offsets along the center line of the slot array antenna. The dielectric substrate layer includes metallic vias symmetrically arranged on both sides of the central line of the antenna to form a substrate integrated waveguide.

A wireless communication system including a shield room forming section, leaky transmission line, first antenna, first device, second antenna and second device. The shield room forming section covers an internal space with an electromagnetic wave reflector that blocks wireless communication. The leaky transmission line is provided with first and second leakage parts arranged inside the shield room forming section. The first antenna is arranged inside the shield room forming section and configured to be wirelessly communicable with the first leakage part. The first device is arranged inside the shield room forming section and has the first antenna. The second antenna is arranged inside the shield room forming section and configured to be wirelessly communicable with the second leakage part. The second device is arranged inside the shield room forming section and has the second antenna. The first device and the second device perform direct two-way wireless communication with each-other.

An in-cabin communication system performs wireless communication between a vehicle and a portable terminal carried by an occupant. The in-cabin communication system includes: a vehicular device mounted to the vehicle; and a leaky coaxial cable that is connected to the vehicular device, and that outputs an electromagnetic wave having a predetermined wavelength according to a command from the vehicular device. The leaky coaxial cable is disposed inside a steel plate of a body of the vehicle. The leaky coaxial cable is disposed at a predetermined distance, which corresponds to an integer multiple of a half-wavelength of the predetermined wavelength, from the steel plate.

In a method for reading from an RFID-tagged article and an RFID system, information is accurately read from an RFID tag while interference with other devices is prevented by use of a compact and simple configuration. An article is conveyed on a conveyor belt. Also, an RFID tag is attached to the article. Information on the RFID tag is read by a leaky coaxial cable that is a stationary read/write antenna in a vicinity of the conveyor belt. The leaky coaxial cable is above the conveyor belt and at least a portion of the cable traverses the conveyor belt.

A wireless proximity detection system employs short-range wireless communication to detect the proximity of a user device within a strictly defined wireless zone and as a result trigger a desired action. The proximity detection system may utilize one or more leaky feeders to define the wireless zone and the associated received signal strength(s) detected by the user's wireless device. Alternatively, a compact planar antenna structure coupled with a highly shielded radio transceiver is used to allow a similar precise low-power radio beam to be emitted defining a small location to enable identification of a wireless device such as a smartphone in a given area in front of the device. The planar antenna structure allows a compact and low-cost fabrication method and the use of common printed circuit fabrication methods provide an integrated solution.

Example proximity sensors are described. The proximity sensor can include a transceiver unit, and a leaky coaxial cable operably coupled to the transceiver unit. The proximity sensor described herein can be used with a steering wheel. For example, the leaky coaxial cable can be embedded in the steering wheel.