摘要:
An antenna includes antenna elements for transmitting and receiving signals. The antenna elements have a helical shape and are disposed parallel to one another. The antenna elements are individually connected in parallel to a common conductor surface and are capacitively coupled to a radio-frequency counterpoise via the common conductor surface.
摘要:
A feedhorn of the invention comprises: at least first and second waveguides in positions so as to face each other over a center line, each having an axis parallel to the center line; and first and second horns on extension lines of the axes. The outer ends of the first and second horns have aperture end faces, respectively. Each of the aperture end faces of the first and second horns is tilted toward the center line by a predetermined angle so that the first and second horns are perpendicular to the travel directions of radio waves transmitted from at least two broadcasting satellites orbiting around the earth and reflected by an antenna on the ground.
摘要:
The present invention provides various wave-guides and support structures that are used in conjunction with feed structures to form compact antennas. Specifically, in one embodiment, the present invention provides a wave-guide design used for connecting the feed of an antenna to various electronics, such as a transmitter or receiver. The wave-guide of this embodiment includes a first end for connecting to the feed and a second end for connection to either a transmitter, receiver, or other electronic components. Importantly, the body of the wave-guide extends in a direction towards the reflector of the antenna so that the second end of the wave-guide is positioned closer to the reflector than the first end of the wave guide. As such, the transmitter or receiver that is connected to the second end of the wave-guide is located in close relationship with the reflector, thereby creating a compact, aesthetically pleasing antenna structure.
摘要:
A multiple beam antenna system including a reflector that is at least partially parabolic in one dimension, a pair of dielectric lenses (or optionally at least one shaped reflector to perform functionality otherwise performed by the lens(es)), and a pair of waveguides. Multiple received beams are received and reflected by the reflector into an orthogonal mode junction which separates signals of a first polarity from signals of a second orthogonal polarity. The signals of the first polarity are forwarded into a first waveguide and the orthogonal signals of the second polarity are forwarded into a second parallel waveguide. A plurality of satellites may be accessed simultaneously thus allowing the user to utilize both signals at the same time. In certain embodiments, each of the dielectric lenses may be of the bifocal type.
摘要:
A multiple beam antenna system including a reflector that is at least partially parabolic in one dimension, a pair of dielectric lenses, and a pair of waveguides. Multiple received beams are received and reflected by the reflector into an orthogonal mode junction which separates signals of a first polarity from signals of a second orthogonal polarity. The signals of the first polarity are forwarded into a first waveguide and the orthogonal signals of the second polarity are forwarded into a second parallel waveguide. A plurality of satellites may be accessed simultaneously thus allowing the user to utilize both signals at the same time.
摘要:
A low cost, highly efficient multiband feedhorn mount assembly for co-locating first and second feedhorns on a ground satellite receiving antenna comprises a first mounting bracket adapted to be secured to an antenna bridge for adjustably supporting the first feedhorn. A second mounting bracket carrying the second feedhorn is adjustably attached to the first mounting bracket such that the first and second feedhorns, when attached respectively to the first and second mounting brackets, may be individually oriented relative to the antenna reflector. Co-located transmissions in different frequency bands from one or more satellites may thus be received without the need for a costly hybrid multiband feedhorn. Methods for installing the assembly are disclosed.
摘要:
The invention relates to an antenna system which is capable of producing multiple, high-gain, independently steerable antenna beams from a single antenna aperture. The system accomplishes this, in part, by utilizing a separate phased array antenna as the feed element of a spherical lens for each desired beam. In this fashion, the beam(s) produced by the antenna system can each be electronically steered (independently of the other beams, if any) and physical movement of the feed element(s) is not required. The invention may also use multiple spherical lenses, wherein each lens includes at least one phased array feed.
摘要:
An antenna system is described including a reflector antenna, responsive to radio frequency signals at a first frequency, having a first reflector surface, a second reflector surface and a Cassegrain feed. The antenna system further includes an array antenna having a plurality of antenna elements responsive to radio frequency signals having a second different frequency, wherein a center element is in a common location with the feed of the reflector antenna. With such an arrangement, an improved dual band antenna system is provided. By providing the center element of the array antenna in a common location with the feed of the reflector antenna, a dual band radio frequency antenna system is provided which is more compact with improved radiation characteristics than known similar configured antennas.
摘要:
A coaxial multiple-mode antenna system (10) is disclosed, including a coaxial input section (14) for coaxially collecting, for example, MMW and IR electromagnetic radiation. The IR radiation is focused to a point at the input section's focal plane, while the MMW beam has a relatively large width in this plane. An interface section (16) includes an IR section (18) and MMW section (20) that allow the two beams to be separately processed with a minimum of losses. In that regard, the MMW section includes a lens (42), having an incident surface, the center of which is positioned at the focal plane. An optical fiber (46) extends axially through the lens and has an incident end that is aligned with the incident surface of the lens. The lens quasi-optically transmits the MMW beam to a detection circuit (26), while the optical fiber transmits the IR beam to detection circuit (22). Because the optical fiber receives the IR beam before it is processed by the lens, IR losses are limited. Further, the small diameter of the optical fiber and its axial alignment in the lens cause minimal disruption of the MMW beam.
摘要:
The present invention relates to a multifrequency antenna comprising a microstrip patch first antenna (10, 11, 12) operating at one or more frequencies, and a second antenna (17) disposed in front of the antenna and using the same radiating surface and operating at a different frequency. The invention is applicable, in particular, to space telecommunications.