Circularly polarized slot radiators
A Broadband Crossed-Slot Circularly Polarized Antenna with Stable Phase Center for GNSS Applications Hongliang Zhang, Yuanyue Guo*, Wenjuan Zhang, and Gang Wang Abstract—A broadband circularly polarized microstrip antenna with stable phase center is proposed for multi-mode GNSS INTERNET-GAMBLING.CC Size: 1MB. Abstract: In certain radar and wireless communication applications, omnidirectional circularly polarized (CP) antennas are desired but existing solutions have complex 3-D structures and are large in size. In this paper, a compact and low profile CP antenna having omnidirectional pattern on azimuthal plane is demonstrated. The CP waveform is synthesized by combining two linearly polarized and Cited by: Jul 21, · Thus, in a conventional waveguide slot antenna for radiating a circularly polarized wave, a linearly polarized wave is converted into a circularly polarized wave by combining a pair of linear slots to generate mutually orthogonal polarized waves, as disclosed in .
Higher signal isolation solutions for printed circuit board mounted antenna and waveguide interface. The waveguide achieves impedance matching between the planar radiator and the horn having a pyramid-shaped square aperture. The above and other objects and features of the present invention will become apparent from the following description of the preferred embodiments given in conjunction with the accompanying drawings, in which:. The horn antenna has a simplified and miniaturized structure by substituting a function of a providing signal power to the horn antenna with a function of a circular polarizer which induces circular polarization by using the planar radiator. The reflector must be built to a precision determined by the wavelength used.
The present invention relates to a horn antenna for circular polarization using a planar-type radiator; and, more particularly to a horn antenna for circular polarization using a planar-type radiator, the antenna which can be used for an antenna system for satellite communication using circular polarization in a high frequency band or which can be used as an element of an array antenna.
Generally, a horn antenna, which is a waveguide antenna, propagates energy through a waveguide by exciting one end of the waveguide and opening the other end to thereby radiate the energy into space through the aperture. As shown, the conventional horn antenna has a complicated structure, which includes an exciter for providing signal power to the horn antenna, a circular polarizer for inducing circular polarization, and a waveguide horn Due to the structural complicacy, it is difficult to design and fabricate the conventional horn antenna and this leads to high production cost.
The structural complicacy also makes the physical size of the horn antenna bigger and thus prohibits it from being applied to various antenna systems using a high-gain array antenna. In order to solve the problem, U. However, since the horn antenna of the cited patent radiates linear polarization energy, it cannot be applied to the antenna system for circular polarization. It is, therefore, an object of the present invention to provide a horn antenna for circular polarization using a planar radiator, the antenna that has a simplified and miniaturized structure by substituting a function of an exciter which provides signal power to the horn antenna with a function of a circular polarizer which induces circular polarization by using the planar radiator.
It is another object of the present invention to provide a wideband high-efficiency antenna that can minimize the narrowband characteristic of the planar radiator and the dielectric loss and radiation loss generated in a high-frequency band by applying a multilayer structure to which a metal plate having an aperture of a predetermined size is inserted in order to improve a narrowband characteristic of the planar radiator.
A slot antenna consists of a metal surface, usually a flat plate, with one or more holes or slots cut out. A slotted waveguide is a waveguide that is used as an antenna in microwave radar applications. When the plate is driven as an antenna by a driving frequency, the slot radiates electromagnetic waves in a way similar to a dipole antenna.
The shape and size of the slot, as well as the driving frequency, determine the radiation pattern. Often the radio waves are provided by a waveguide , and the antenna consists of slots in the waveguide. Slot antennas are usually used at UHF and microwave frequencies, where the waves are usually conducted by waveguide, so a slot in the waveguide makes a simple antenna. They are often found in standard desktop microwave sources used for research purposes.
A slot antenna's main advantages are its size, design simplicity, and convenient adaptation to mass production using either waveguide or PC board technology. An antenna consisting of multiple parallel slots in a waveguide is a widely used array antenna which radiates a narrow fan-shaped beam of microwaves at right angles to the waveguide, with its narrow axis in the plane of the waveguide and its wide axis perpendicular to the waveguide.
Multiple slot versions are widely used in radar antennas, particularly marine radar antennas on ships, and for the sector antennas used for cell phone base stations. Due to Babinet's principle a slot in a waveguide has the same radiation pattern as a driven rod antenna whose rod is the same shape as the slot. This can be used to determine the radiation pattern using calculations for a more conventional antenna. Usually a slotted waveguide antenna is protected by microwave transparent material, which may visually obscure the slots.
Nevertheless, it is easily distinguished from a parabolic reflector by its flat or tube shape. He invented it in order to produce a practical type of antenna for VHF television broadcasting that would have horizontal polarization, an omnidirectional horizontal radiation pattern and a narrow vertical radiation pattern.
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