Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 10 of 10 for “"array feed"”.
-
Characterization of a Phased Array Feed Model
… accurate software based models of phased array feeds (PAFs) is one of many steps to successfully integrating PAFs with current and future radio telescopes, which is a goal of many groups around the globe. This thesis characterizes the latest models of a 19 element hexagonal PAF of dipoles …
-
A Prototype Platform for Array Feed Development
… utilizes spatial filtering by placing an array of electrically small antennas at the focal plane of a parabolic reflector. This thesis documents the design and characterization of a prototype array feed and RF receiver that were used to demonstrate the spatial filtering principle. The …
-
A UHF Multimode Array Feed for the Westford Radio Telescope
A novel UHF Multimode Array Feed (MMAF) has been created for MIT’s Westford Radio Telescope. The MMAF is a dual-linear focal plane array installed concentrically with the existing QRFH feed on the telescope, enabling a combined system capable of transmit or receive on UHF radar and satcom …
-
Composite Right-Left Handed Stripline Structures for Antenna Array Feed Networks
… are proposed as viable key structures in antenna array applications, enabling reduction of the overall feed network sizes as well as allowing integration opportunities and possible reduction of radiating beam pattern distortions.</p> <p>A via-less composite right/left-handed stripline unit cell is …
-
Nineteen-Element Phased-Array Feed Development and Analysis on Effects of Focal Plane Offset and Beam Steering on Sensitivity
… to a nineteen-element platform for phased array feed experiments. The nineteen-element system was deployed at the National Radio Astronomy Observatory (NRAO) in Green Bank West Virginia for use on the Green Bank 20-Meter Telescope. Numerical simulations were performed to determine how …
-
Beamforming Techniques and Interference Mitigation Using a Multiple Feed Array for Radio Astronomy
… interference can be mitigated using a phased array feed in conjunction with a large reflector. A phased array feed would allow radio astronomers to observe fainter signals than is currently possible, while at the same time enabling rapid sky surveys. A phased array feed was designed and …
-
Analysis and Optimization of Reflector Antenna Systems (Pattern Calculation, Optimum Directivity, Sidelobe Reduction)
… reflector antenna system being illuminated by an array feed with arbitrary location, polarization, and orientation. The methods of analysis used are physical optics (PO) and the application of the Fast Fourier Transform (FFT) to the aperture fields obtained using geometrical optics (GO), …
-
On the synthesis of optimum monopulse antenna array distributions
… antennas of high performance. For this reason arrays are finding increasing application as monopulse antennas. A new exact procedure is introduced for the synthesis of optimum difference distributions for linear arrays of discrete elements, with a maximum sidelobe level specification. The …
-
Single-band and Dual-band Beam Switching Systems and Offset-fed Beam Scanning Reflectarray
The reflectarray has been considered as a suitable candidate to replace the conventional parabolic reflectors because of its high-gain, low profile, and beam reconfiguration capability. Beam scanning capability and multi-band operation of the microstrip reflectarray have been main research topics …
-
A synthesis procedure for array feeds to improve radiation performance of large distorted reflector antennas
… is implemented by weighting the elements of an array feed. In most of the studies, a precise knowledge of the reflector surface is required. An alternative approach to electromagnetic compensation is presented in this study. The proposed technique uses pattern synthesis to compensate for the …