摘要:
In order to transmit a signal received in a GPS antenna (20) to a GPS receiver body (30) through a glass plate (40), a signal transmission circuit (10) is divided into first and second signal transmission parts (11, 12). The first signal transmission part (11) is for transmitting a high frequency signal from an output terminal (20out) of the GPS antenna (20) to a first surface (41) of the glass plate (40). The second signal transmission part (12) is for transmitting the high frequency signal from a second surface (42) of the glass plate (40) to an input terminal (30in) of the GPS receiver body (30). The first signal transmission part (11) includes a first coaxial cable (111), a first electrode pair (112), a first balanced line (113), and a first balun (114). The second signal transmission part (12) includes a second coaxial cable (121), a second electrode pair (122), a second balanced line (123), and a second balun (124).
摘要:
In a helical antenna comprising a hollow cylindrical member having an inner peripheral surface and an outer peripheral surface and an antenna pattern film wound around the outer peripheral surface of the hollow cylindrical member, the helical antenna further comprises a center rod coaxial with a center axis of the hollow cylindrical member and at least three ribs disposed between the center rod and the inner peripheral surface of the hollow cylindrical member. The ribs symmetrically extends in a radial manner at equal angular intervals. The hollow cylindrical member, the center rod, and the ribs preferably may be integrally molded out of plastic. The antenna pattern film may comprise a flexible insulator film and a conductive pattern formed on the flexible insulator film. The conductive pattern has at least one antenna lead member which is wound around the outer peripheral surface of the hollow cylindrical member in a helix fashion.
摘要:
A helical antenna includes a hollow cylindrical member having an inner peripheral surface and an outer peripheral surface, an antenna pattern film wound around the outer peripheral surface of the hollow cylindrical member, a center rod coaxial with a center axis of the hollow cylindrical member, and at least three ribs disposed between the center rod and the inner peripheral surface of the hollow cylindrical member. The ribs symmetrically extend in a radial manner at equal angular intervals. The hollow cylindrical member, the center rod, and the ribs preferably may be integrally molded out of plastic. The antenna pattern film may include a flexible insulator film and a conductive pattern formed on the flexible insulator film. The conductive pattern has at least one antenna lead member which is wound around the outer peripheral surface of the hollow cylindrical member in a helix fashion.
摘要:
A bushing is provided for placement on a cable to be held between an upper cover and a lower cover of an apparatus. The bushing has a flange on an outer peripheral surface thereof, and the flange extends perpendicular to the cable on which the bushing is put. The upper cover and the lower cover of the apparatus are attached to form a unit, and the upper cover comprises a flange receiving portion. The flange comes closely into contact with the flange receiving portion to fix the cable against the upper cover and serve as a watertight packing. As a result, a simple watertight structure is provided.
摘要:
To provide an antenna unit that can always provide good broadcast transmission reception and a signal switching circuit to be used therein. A first antenna element for receiving satellite broadcast transmissions, a second antenna element for receiving VHF terrestrial broadcast transmissions, and a switching means for selectively switching output of either a reception signal of the satellite broadcast transmissions received by the first antenna element or a reception signal of the VHF terrestrial broadcast transmissions received by the second antenna element and supplying that output to the receiver unit via the signal supply cable in response to a direct-current bias level supplied from a receiver unit via a signal supply cable are provided inside a single identical casing.
摘要:
In an electromagnetic coupling type four-point feeding loop antenna (10) comprising a tubular body (11), a loop portion (12) having a loop width (W1), four feeders (13) each having a feeder width (W2), and four electromagnetic coupling wires (17) each having a coupling wire width (W3), the loop width, the feeder width, and the coupling wire width are substantially equal to one another. A gap (&dgr;) between the feeder and the electromagnetic coupling wire is laid in a range between 0.2 mm and 0.8 mm, both inclusive, when the electromagnetic coupling type four-point feeding loop antenna has a feeding impedance of a range between 25 &OHgr; and 100 &OHgr;, both inclusive.
摘要:
A shield cover is disposed so as to be opposed to a bottom plate and electromagnetic-shields a signal processing circuit mounted on a rear surface of a circuit board. The shied cover has a ceiling portion which includes a mounter vacuumed portion disposed in a center portion of the ceiling portion and vacuumed by a vacuum nozzle of a mounter, a ring-shaped outer edge disposed from an end of the side wall portion inwardly, and a plurality of beam portions joining the mounter vacuumed portion to the outer edge. An electromagnetic shielding of the signal processing unit is carried out using both of the shield cover and the bottom plate.
摘要:
To provide an antenna device adapted to interrupt jamming waves and enable cost reduction, a high-pass filter (HPF) adapted to interrupt general-use frequencies at least near a low-frequency side of a pass band intended for use is provided as a frequency selection circuit 11A on the antenna 1 side in an initial-stage LNA 2A. By setting a low-side cutoff frequency to 900 MHz, it is possible to prevent reception of frequencies in a general-use frequency band with a high frequency of use as jamming waves. That is, for example, it is possible to prevent reception of frequencies in 800 to 900 MHz band for mobile cellular telephones and higher harmonics thereof as jamming waves. Further, since an additional filter is not required in the antenna device, the circuit structure can be simplified.
摘要:
Disclosed is an antenna apparatus comprising: an antenna module comprising a ground plate and an antenna element having a metal plate disposed at a predetermined distance from the ground plate; and an antenna cover to cover the antenna module, wherein the antenna cover includes an antenna holding section to hold the antenna module, and a mounting section which is integrally formed on the antenna holding section to mount the antenna cover on external equipment.