A device for information transmission, a so-called transponder, for receiving a first microwave signal, modulating and coding, and retransmitting a second microwave signal, having at least one antenna made in microstrip technique is described. The device is characterized primarily in that the antenna has an antenna layer (20), acting towards a ground plane (21), the antenna layer and the ground plane essentially equal area, and in that the device further having a reflex position (23 ), arranged next to or at a distance of at most 1/6 of the air wave length of the first microwave signal from the edges of the antenna layer and the ground plane, so that an antenna lobe directional from the antenna is obtained, including directly transmitted microwave signal and reflected microwave signal. With this embodiment a device is obtained that is compact, effective, light and inexpensive and gives well defined and directional antenna lobe for communications with good range.
A radio frequency automatic identification system detects targets which include a plurality of radio frequency resonators. Information is attributed to the target in accordance with the radio frequency response characteristics of the target, such as the resonant frequencies of resonators present, and/or the spatial locations within the target of the resonators. Preferred resonators include thin dipoles, which may be metallizations on a plastic film substrate. Information may be attributed to a target by fabricating the target with resonators disposed at locations to encode information in accordance with a predetermined encoding system; alternatively, resonators may be randomly disposed, and a translation code applied to convert the radio frequency information to particular information in a particular format. Readers for use in the system read the radio frequency response characteristics of a target in the near field of a radiating aperture which is illuminated by a radio frequency source. Items which may be encoded with radio frequency readable information include documents, credit cards, and computer diskettes.
In a radio signal detecting system, an antenna is rotatably mounted on a wrist watch type case, and this antenna is manually rotated to receive a radio signal reflected from a target to be distance-measured every time the antenna is rotated by a preselected rotation angle. The reflected radio signal is digitally converted into field strength data, or distance data. These field strength data, or distance data are sequentially stored into a memory circuit in correspondence with the rotation angle of the antenna. Since the data stored into the memory circuit at every rotation angle for the antenna are displayed on a liquid crystal display unit, the radio signal detecting system can be made compact and operated under low power consumption.
It is an object of this invention to provide a wrist watch containing an RFID tag which maintains a sense of luxury and has comparatively high sensitivity. The wrist watch containing tag of this invention comprises a watch case having a ring-shaped frame, a glass lid, and a bottom lid; a drive section which is accommodated inside the watch case; a display section for displaying time which is driven by the drive section; and an RFID tag which is accommodated inside the watch case and comprises an antenna and an IC chip; the ring-shaped frame and/or the bottom lid having at least one slit therein, and the antenna comprising a wound coil which runs along the inner face of the ring-shaped frame so as to surround the drive section. The slit is filled with a nonconductive resin, affixing the opposing cutaway planes together.
An array substrate for use in a liquid crystal display device includes a thin film transistor as a switching element, having a gate electrode, a source electrode and a drain electrode, wherein the gate electrode is a portion of a gate line near the crossing of the gate and data lines, and has an inverted "T"-shaped opening or a rectangularly-shaped opening. The drain electrode is shaped like the inverted "T"-shape and corresponds to the opening of the gate electrode. The source electrode surrounds the drain electrode along the steps of the semiconductor layer. Accordingly, in the thin film transistor having this structure, the gate electrode is only overlapped by the edges of the drain electrode. And thus, the gate-drain parasitic capacitance is reduced and minimized. Also, variations in the gate-drain parasitic capacitance are prevented. As a result, a high resolution is achieved and the picture quality is improved in the liquid crystal display device.
A radio frequency identification (RFID) transponder (tag) includes a spiral over ground plane antenna. The RFID tag includes a RFID circuitry that may be implemented as an RFID tag integrated circuit and may be mounted on one surface of a substrate such as a printed circuit board. The RFID tag circuitry may be electrically connected to an impedance matching circuit printed on the same side of printed circuit board. The matching circuit is electrically connected to a spiral antenna that may be mounted on same side of the printed circuit board as the tag circuit and matching circuit. The spiral antenna is held a prescribed distance from the ground plane in order to maximize the gain of the RFID tag and to thereby maximize the range of the RFID tag.