2,442 research outputs found
A systematic study of focal ratio and effects of optical misalignment for LST
Possible large space telescope geometries are studied to determine performance and the effects of misalignments. The results are displayed parametrically as a function of relative back focal distance (RBFD). As RBFD increases, a larger high resolution field is obtained, and misalignment effects become less severe
Strain gauge ambiguity sensor for segmented mirror active optical system
A system is described to measure alignment between interfacing edges of mirror segments positioned to form a segmented mirror surface. It serves as a gauge having a bending beam with four piezoresistive elements coupled across the interfaces of the edges of adjacent mirror segments. The bending beam has a first position corresponding to alignment of the edges of adjacent mirror segments, and it is bendable from the first position in a direction and to a degree dependent upon the relative misalignment between the edges of adjacent mirror segments to correspondingly vary the resistance of the strain guage. A source of power and an amplifier are connected in circuit with the strain gauge whereby the output of the amplifier varies according to the misalignment of the edges of adjacent mirror segments
Elf: computer automation and error correction for a microwave network analyzer
A microwave measurement system has been developed that combines a personal computer (PC) and an conventional vector network analyzer to yield a full complex-error-corrected automatic network analyzer. The system consists of a Hewlett-Packard HP 8410C network analyzer, an HP 8350B sweep oscillator, and an IBM PC. A program called Elf runs on the PC, performing calibration and measurement algorithms and providing a flexible, menu-oriented user interface. The system, when calibrated, achieves a worst-case measurement error vector of magnitude ≤ 0.02 for transmission and reflection coefficient measurements over the 2-12.4-GHz frequency range and has a measurement speed of three frequency points/s. Elf provides an inexpensive method for upgrading the HP 8410 to achieve the high accuracy of an automatic network analyzer
Puff, an Interactive Microwave Computer Aided Design Program for Personal Computers
We will demonstrate a CAD program designed for the lay out
and analysis of microstrip circuits. The program runs on the
IBM PC or AT. Circuit elements are selected from a parts list
and drawn on the screen using the cursor keys. The analysis
may then be performed, directly from the screen drawing. Puff
has been used by microwave students in classes at the California
Institute of Technology and the University of California at Los
Angeles
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