相关论文: Implementation of an Optimised Cassegrain System f…
Large imaging arrays of detectors at millimeter and submillimeter wavelengths have applications that include measurements of the faint polarization signal in the Cosmic Microwave Background (CMB), and submillimeter astrophysics. We are…
Microstrip patch antennas are low-profile and robust when mounted on rigid surfaces of the devices making them suitable for communication and millimeter-wave applications. In this paper, an antenna is designed for the resonant frequency of…
We are contructing an interferometric telescope, the Very Small Array, to study the cosmic microwave background on angular scales 0.2--4.5 degrees. The physical layout and electronic design of the telescope are optimised to give maximum…
We summarise the mathematical foundation of the holographic method of measuring the reflector profile of an antenna or radio telescope. In particular, we treat the case, where the signal source is located at a finite distance from the…
Image quality in mosaicked observations from interferometric radio telescopes is strongly dependent on the accuracy with which the antenna primary beam is calibrated. The next generation of radio telescope arrays such as the Allen Telescope…
This letter presents the first experimental results of our three-dimensional (3D) millimeter-wave (mm-wave) Compressive-Reflector-Antenna (CRA) imaging system. In this prototype, the CRA is 3D-printed and coated with a metallic spray to…
We report the first use of Michelson interferometry on the Keck I telescope for diffraction-limited imaging in the near infrared JHK and L bands. By using an aperture mask located close to the f/25 secondary, the 10 m Keck primary mirror…
We report development of a simple and affordable radio interferometer suitable as an educational laboratory experiment. With the increasing importance of interferometry in astronomy, the lack of educational interferometers is an obstacle to…
Aberration compensation with emphasis on the generalized spherical aberration components is discussed for plane-symmetric and anamorphic optical systems. A narrow field-of-view double-plane symmetric telescope objective containing…
We propose and demonstrate a compact acoustic retroreflector that reroutes probing signals back towards the source with minimal scattering. Gradient refractive index (GRIN) acoustic metamaterials, based on Archimedean spiral structures, are…
We describe a system being developed for measuring the shapes of the mirrors of the Fred Young Submillimeter Telescope (FYST), now under construction for the CCAT Observatory. "Holographic" antenna-measuring techniques are an efficient and…
In this paper, the design, realization, and demonstration of a broadband millimeter-wave imaging system based on the synthetic aperture radar technique (SAR) are discussed. The proposed system, operating within the frequency range of…
We develop a proto-model of an off-axis reflective telescope for infrared wide-field observations based on the design of Schwarzschild-Chang type telescope. With only two mirrors, this design achieves an entrance pupil diameter of 50 mm and…
We propose a low-pretension reflective kirigami film as a material for the reflective surfaces of large deployable space reflector antennas with an operating frequency around 10 GHz. The kirigami cut pattern is based on the well-known…
This paper presents a reflectarray compact antenna test range (RACATR). The new range layout is designed to suppress the unwanted diffraction. A fast near field optimization method has been used to determine the phase distribution of the…
Studies are under way to propose a new generation of post-VLTI interferometers. The Carlina concept studied at the Haute- Provence Observatory is one of the proposed solutions. It consists in an optical interferometer configured like a…
Fundamentally new technology is described for constructing low areal mass density (1kg/m^2), high precision (< 10micron RMS) reflectors scalable to large apertures (10 to 20 meters) for use as the primary element of a telescope system. A…
A new optical design concept of telescopes to provide an aberration-free, wide field, unvignetted flat focal plane is described. The system employs three aspheric mirrors to remove aberrations, and provides a semi-circular field of view…
We present a concept of the X-ray imaging system with high angular-resolution and moderate sensitivity. In this concept, a two-dimensional detector, i.e., imager, is put at a slightly out-of-focused position of the focusing mirror, rather…
In this work, a method is presented to maximize the obtained gain from millimeter-wave (mm-wave) lens antennas using phase center analysis. Commonly, for designing a lens antenna, the lens is positioned just on top of the antenna element…