 Digital display plug-in |
| OF A PREFERRED EMBODIMENT FIG. 1 shows a block diagram of the digital display module 10 (area ... |
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| Integrated circuit with frequency-dividing circuits capable of being tested at a high speed |
| In view of the aforesaid problem inherent in the conventional circuit, the principal object of the ... |
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| Fast search and lock-on means for distance measuring equipment |
| I claim: 1. In an electronic ranging system, means for generating a range gate in time synchronism ... |
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| Coil assembly |
| According to the present invention, a coil assembly, particularly attractive in the case of a coil ... |
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| Antenna alarm assembly for vehicle |
| It is an object of the invention to provide an antenna assembly for vehicle radio transceiver which ... |
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| Measuring apparatus for detecting the distance "H" to an object |
| What is claimed is: 1. A measuring apparatus for detecting the distance h to an object, said ... |
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| Phase comparison systems employing improved phaselock loop apparatus |
| It is accordingly an object of the present invention to provide improved phaselock loop apparatus ... |
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| Desk organizer unit |
| In the present invention, a vertically movable desk organizing device for office supplies and ... |
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| Leatherlike fabrics |
| I claim as my invention: 1. A fabric of interlaced multi-fiber yarns having a nap of fibers ... |
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| Corrugated paper board |
| OF THE PRESENT INVENTION In the aforementioned copending application Ser. No. 599,142, filed July 2... |
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Wideband polarization-transforming electromagnetic mirror
| Details |
Inventors: Shelton, J. Paul;
Assignee: The United States of America as represented by the Secretary of the Navy (Washington, DC)
Primary Examiner: Lieberman; Eli
Assistant Examiner:
Attorney, Agent or Firm: Sciascia; R. S., Schneider; Philip, Ranucci; Vincent
A reflecting mirror for transforming the polarization of electromagnetic ) waves independently of the frequency of the waves and, thus, over an arbitrarily wide RF bandwidth includes two interleaved sets of planar arrays of resonant elements, both being orthogonally polarized, and each set comprising layers of the arrays which are arranged so that the layered elements of each set form a log-periodic configuration. The difference in phase between the reflection coefficient functions of the first and second sets of arrays is independent of the frequency of EM waves. Each of the arrays resonates at a different frequency and the arrays resonate over the frequency band of operation. A plane EM wave, the polarization of which has two vector components, strikes the mirror on the array having the shortest strips. The two polarization components of the wave travel into the mirror. Each component is reflected as it encounters strips of an array having a resonance which matches the resonant frequency of the component. The components being non-parallel to each other are reflected from different arrays which causes the components to change in phase relative to each other, thereby transforming the polarization of the wave. |
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DETAILED DESCRIPTION The general purpose and object of the present invention is to transform the polarization of EM waves into any desirable type of polarization independently of the frequency of a signal.
This and other objects of the present invention are accomplished by a reflecting mirror comprising two interleaved sets of layered planar arrays, each array having a regular lattice of parallel, resonant elements, the arrays of one set being alternately layered with the arrays of the other set, the layered elements of each set forming a log-periodic configuration, and the elements of each set being perpendicular to the elements of the other set so that the sets are orthogonally polarized.
Each set has a reflection coefficient function which varies essentially linearly with the logarithm of frequency.
The difference in phase between the reflection coefficient functions of the two sets of arrays is constant with frequency.
This phase-difference between the reflection-coefficient functions causes the polarization of an incident wave to transform upon reflection of the wave.
The phase difference is a function of the scale factor from a polarized array of one set to the next succeeding polarized array of the other set, and is not a function of the difference between the reflective path lengths of the components of polarization.
Therefore, the polarization-transformation properties of the invention are not sensitive to wavelength or frequency.
The log-periodic, three-dimensional configuration of interleaved horizontally and vertically polarized arrays is a novel feature of the reflecting mirror.
The advantage of the invention is that a polarization of EM waves may be transformed into another type of polarization over an arbitrarily wide bandwidth.
Thus, the invention provides a frequency-independent solution to a problem, for example, of requiring a dedicated antenna for each radar system on naval vessels.
Other objects and advantages of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawing wherein:
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Radio 
