Yuichiro Yamaguchi

A flat roof automobile antenna module for LTE, GPS and SDARS applications

A flat car-roof antenna module for LTE, GPS and SDARS applications is proposed. The module consists of a planar inverted-F antenna (PIFA), a square loop one and a circular loop one, for the LTE, GPS and SDARS operations, respectively. The three antennas are located in a same plane parallel to car roof and put close to each other so that the dimension of the module is only 70 × 70 mm2 in plane. Gap between the antenna plane and the car roof is only 20 mm. This low profile makes the module almost invisible when it is installed on a car roof.

An invisible vehicle roof antenna

An invisible vehicle roof antenna for the long term evolution (LTE) application is proposed. The antenna is a bended ultra-wideband monopole with a low profile of 30 mm and covers the LTE operation bands. The antenna is embedded into a hole with a depth of 30 mm which is opened on the roof and is surrounded by metal. The antenna becomes completely invisible when the hole is covered by a dielectric lid. A slit is made on the horizontal part of the antenna to suppress a zenith-directional radiation so that the antenna has enough gain in horizontal directions, even the antenna is surrounded by the metal wall of the hole. The antenna has a dimension of 85×85×30 mm3 and is embedded into a hole of 200×200×30 mm3.

A flat car-roof antenna module for phone and GPS applications

A flat car-roof antenna module for phone and GPS applications is proposed. The module consists of a planar inverted-F antenna (PIFA) for the phone operation and a planar loop antenna for the GPS one. The two antennas are located in a same plane parallel to car roof and put close to each other so that the dimension of the module is only 50 × 80 mm2 in plane. Gap between the antenna plane and the car roof is only 19 mm. This low profile makes the module almost invisible when it is installed on a car roof. Even with this narrow gap, the two antennas keep high performance in their operation frequencies.

A wire-grid type transparent film UWB antenna

In this paper we have introduced transparent wire-grid type conductive film antenna, made of Ag-paste. The wire-grid has wire-width of only a few microns and makes the conductive film almost invisible. The antenna is designed to cover an ultra-wide band (UWB) from 2 to 6 GHz and the radiating part is made with different mesh sizes of the conductive film and ground has been taken with continuous sheet. Performance of these mesh antennas is compared with a full Cu-sheet antenna. Input characteristics and radiation patterns are approximately the same as that of the Cu-antenna. Even the wire-grid is so sparse, the radiation efficiency is higher than 50% at most frequencies. In the later part of this paper, vertical slit and horizontal slit antennas made of Cu-sheet are investigated. The horizontal slit antenna shows deviation in the results, whereas the vertical slit and full Cu antenna are matching the results to each other for the UWB of 2–6 GHz. Vertical and horizontal slit antennas confirm the appropriate polarization.