Abstract:
In the field of circular-polarized planar wire antennas for very wide band telecommunications systems, and an antenna reflector for such an antenna, an antenna device comprises an antenna reflector and an antenna, and a method for implementing the antenna reflector. The antenna reflector comprises, on the one hand, a first reflection region exhibiting electromagnetic properties of an electrical conductor in a first sub-band of frequencies and, on the other hand, a second reflection region exhibiting electromagnetic properties akin to a magnetic conductor in a second sub-band of frequencies. Each reflection region is designed to face a region of the antenna able to emit electromagnetic radiation in the corresponding sub-band of frequencies in order to reflect the electric field of the backward radiation in phase with the electric field of the forward radiation.
Abstract:
A small antenna device having an increased gain is provided. The antenna device includes a multilayer dielectric substrate composed of a combination of a plurality of dielectric layers, wherein a feeding antenna is provided in a lower layer of the multilayer substrate, a reflective metal plate is provided above the feeding antenna, and circular or rectangular metal loops are arranged so as to be of increasing diameter from lower layers toward upper layers in the plurality of dielectric layers.
Abstract:
An object of the invention is to provide a slot array antenna in which unstable factors for contact of an adjustment portion comprising a slot waveguide and a waveguide holder are removed, a number of parts is decreased to save weight, and assembly is simplification. Accordingly, this invention is to constitute a radiation portion (1) unitedly of a slot waveguide (1a), a flare holder (1b), and a supported portion (1d), if necessary, further adding a screen holder (1c) for a screen (4) for cross polarization suppression. Furthermore, this invention is to constitute a reinforcement feeder (2) unitedly of a feeder waveguide (2a), a reinforcement portion (2b) and a reinforcement connector (2c) in the case of an open type antenna.
Abstract:
A filter including an enclosure, a dielectric material within the enclosure, at least two microstrip antennas within the enclosure, and at least one frequency selective surface including a metallic pattern. The frequency selective surface is utilized to filter an electromagnetic signal propagated within the enclosure. The geometry of the antennas and the frequency selective surfaces as well as the resonant frequencies of the frequency selective surfaces determine whether the filter is a bandpass, bandstop, notched, or combination filter. If the frequency selective surface is omitted, the combination acts as a delay circuit for delaying the electromagnetic signal, where the time delay is a function of the dielectric constant of the dielectric material.
Abstract:
A microstrip backfire antenna which combines the microstrip type antenna ment with a backfire cavity to provide more than three times the gain over a single microstrip element and thereby be capable of replacing four or more elements of a conventional microstrip array. The microstrip backfire antenna consists of a microstrip element in a cavity between a total reflector and a partial reflector and is characterized by multiple reflections of electromagnetic waves between the two reflectors and by energy being radiated normal to and through the partial reflector.
Abstract:
An optimized reflector antenna is provided which includes a reflector with a rim of adjustable width around its perimeter and a feed system having a predetermined spacing from the reflector. The rim is excited by radiation coupling and its edge acts like a secondary radiator that yields a substantial and unique effect on the radiation patterns of the antenna by preselecting the rim dimensions in amplitude and phase in reference to the feed system.
Abstract:
A lightweight aerial mast for electromagnetic waves is provided with a planar reflector fixed to the top of the mast for reflecting waves onto a planar reflector near the ground, which in turn reflects the waves to a parabolic reflector at whose focus there is a horn aerial. The parallelism of the two planar reflectors is made independent from the bending of the mast due to a connection between these two reflectors provided by three parallel wires of equal lengths which are held taut.
Abstract:
A multi-beam antenna module includes a radio frequency circuit board, a plurality of reflecting plates and a plurality of area coverage feed antenna groups. Each of the area coverage feed antenna groups includes a feed antenna. The reflecting plates have different arrangement directions, and each of the reflecting plates is arranged relative to the feed antenna of each of the area coverage feed antenna groups, thereby changing a radiation pattern of the feed antenna of each of the area coverage feed antenna groups to deflect a main radiation direction of the feed antenna of each of the area coverage feed antenna groups.