Results 251 to 260 of about 139,447 (303)
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Applied Optics, 1966
A rotating-field phase shifter is described which permits continuous electronic tuning of birefringent filters over extended spectral regions. The use of such phase shifters reduces the conditions for tuning synchronism between all filter stages to a simple relationship between the electrical driving frequencies.
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A rotating-field phase shifter is described which permits continuous electronic tuning of birefringent filters over extended spectral regions. The use of such phase shifters reduces the conditions for tuning synchronism between all filter stages to a simple relationship between the electrical driving frequencies.
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2012
Most current radio receivers use SAW bandpass filters for band selection. Their center frequency depends on the dimensions of the interdigital structure. Therefore, in the next few years, SAW technology will face some fabrication process limits because of the need of higher operating frequencies. BAW resonators are emerging as an alternative technology.
Razafimandimby, S. +3 more
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Most current radio receivers use SAW bandpass filters for band selection. Their center frequency depends on the dimensions of the interdigital structure. Therefore, in the next few years, SAW technology will face some fabrication process limits because of the need of higher operating frequencies. BAW resonators are emerging as an alternative technology.
Razafimandimby, S. +3 more
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Ferroelectric liquid crystal tunable filters
Annual Meeting Optical Society of America, 1989Rapidly tunable optical filters have applications in remote sensing, signal processing, colorimetry, color displays, and communications. In this paper we present simulation and experimental results of electronically tunable filter structures employing smectic A* electroclinic and smectic C * liquid crystals.
H J, Masterson, G D, Sharp, K M, Johnson
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SPIE Proceedings, 2005
The advantages of low cost amplifier solutions in single-channel link extender or loss compensator systems cannot be fully realized unless the ASE noise around the signal peak is removed. Doing so requires a cost-effective solution with high performance, including low insertion loss (
Eugene Y. Ma +2 more
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The advantages of low cost amplifier solutions in single-channel link extender or loss compensator systems cannot be fully realized unless the ASE noise around the signal peak is removed. Doing so requires a cost-effective solution with high performance, including low insertion loss (
Eugene Y. Ma +2 more
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SPIE Proceedings, 2003
Many astronomical researches make use of narrow-band observations to isolate specific spectral features. We present a project to implement an imaging tunable interference filter, representing an observational facility that can greatly expand the capabilities of the instrumentation currently mounted at TNG.
Carlotta Bonoli +3 more
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Many astronomical researches make use of narrow-band observations to isolate specific spectral features. We present a project to implement an imaging tunable interference filter, representing an observational facility that can greatly expand the capabilities of the instrumentation currently mounted at TNG.
Carlotta Bonoli +3 more
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Electronically Tunable Filters
IEEE Microwave Magazine, 2009In this article, a brief introduction to the development of tunable filters was given. A classical design technique based on a combline filter approach was shown, where minimum degradation in passband performance could be obtained across a broad-tuning range.
Peng Wong, Ian Hunter
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Proceedings of the IRE, 1951
Heretofore, tunable waveguide filters have consisted of cavities connected with quarter-wavelength coupling lines and tuned by means of a lumped reactance in the cavity. Such filters exhibit asymmetrical frequency response and a bandwidth proportional to the cube of frequency when tuned.
W. Sichak, H. Augenblick
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Heretofore, tunable waveguide filters have consisted of cavities connected with quarter-wavelength coupling lines and tuned by means of a lumped reactance in the cavity. Such filters exhibit asymmetrical frequency response and a bandwidth proportional to the cube of frequency when tuned.
W. Sichak, H. Augenblick
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Optical Engineering, 1981
This article reviews the types and capabilities of birefringent filters. The general operating principles of Lyot (perfect polarizers), partial polarizing, and Solc (no internal polarizers) filters are introduced. Appropriate techniques for tuning each filter type are presented.
Alan M. Title, William J. Rosenberg
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This article reviews the types and capabilities of birefringent filters. The general operating principles of Lyot (perfect polarizers), partial polarizing, and Solc (no internal polarizers) filters are introduced. Appropriate techniques for tuning each filter type are presented.
Alan M. Title, William J. Rosenberg
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Measurement Science and Technology, 2003
We present the details of a new tunable optical filter, suitable for selecting different bands of wavelength in the UV, visible and IR regions. The filter comprises a ferrofluid-based emulsion cell (emulsion sandwiched between two transparent sheets), a miniature solenoid and a variable direct current source for changing the magnetic field inside the ...
John Philip +3 more
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We present the details of a new tunable optical filter, suitable for selecting different bands of wavelength in the UV, visible and IR regions. The filter comprises a ferrofluid-based emulsion cell (emulsion sandwiched between two transparent sheets), a miniature solenoid and a variable direct current source for changing the magnetic field inside the ...
John Philip +3 more
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Polarization-based tunable interferometric filter
Applied Optics, 1998A polarization-based tunable interferometric filter essentially consisting of a two-beam interferometer with birefringence elements is described. The analysis of the filter is done through the concept of a geometric phase in optics-namely, the Pancharatnam phase. The transmission characteristics of the filter can be controlled through three parameters:
E M, Frins, W, Dultz
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