| Multi-Channel Impulse Radiating Antennas with Polarization Diversity |
JAN 1999 |
31 pages |
| Authors:
Everett G. Farr; Leland H. Bowen; Carl E. Baum; William D. Prather; FARR RESEARCH ALBUQUERQUE NM
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 | The tri-impulse radiating antenna (IRA) and quad-IRA are derived here from earlier versions of Impulse Radiating Antennas. In the new designs, the aperature is divided into three, four, or more sections to provide at least two receive channels and at least one transmit channel, all within a very compact structure. The two receive channels allow reception in two orthogonal polarizations. This configuration is useful when searching for mines using the ... |
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| Multifunction Impulse Radiating Antennas: Theory and Experiment |
NOV 97 |
15 pages |
| Authors:
Everett G. Farr; Carl E. Baum; William Pruther; FARR RESEARCH ALBUQUERQUE NM
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| A Multifunction Impulse Radiating Antenna (IRA) is an extension of a standard IRA that has the additional flexibility of an adjustable beam width. This a just ability is implemented by defocusing the feed to select between a narrow or broad beam. We provide the theory of operation of the antenna, for both in focus and out of focus situations. Furthermore, we built and tested a design with a 46 cm ... |
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| A Comparison of Exact Versus Perturbed Pole Locations of Dielectric Objects in Dielectric Medium |
03 JUL 1997 |
13 pages |
| Authors:
Mark C. Worthy; Carl E. Baum; PHILLIPS LAB KIRTLAND AFB NM
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| The dielectric properties of soils and plastic targets are given. The approach for finding exact pole locations from a dielectric infinite slab, a dielectric sphere, and a dielectric infinite cylinder is presented (and applied) . The exact poles for the slab and sphere are found for various sizes and dielectric properties. There is a discussion (and use) of Carl E. Baum's perturbation formulas for dielectric slabs and spheres. George Hanson's ... |
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| Perturbation Formula for the Internal Resonances of a Dielectric Object Embedded in a Low-Impedance Medium |
12 AUG 1996 |
12 pages |
| Authors:
George W. Hanson; Carl E. Baum; PHILLIPS LAB KIRTLAND AFB NM
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| A simple perturbation formula is presented for characterizing the natural frequencies of a dielectric object embedded in an isotropic, homogeneous medium of low wave impedance. For this situation the natural frequencies of the object can be obtained from the interior "cavity" resonances of the same object when immersed in a perfect conductor. Since the cavity modes are assumed to be known or easily measurable for a given body of interest, ... |
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| Concerning the Identification of Buried Dielectric Targets |
24 JUL 1994 |
24 pages |
| Authors:
Carl E. Baum; PHILLIPS LAB KIRTLAND AFB NM
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| For identifying dielectric targets buried in a lossy dielectric such as soil, one can use the natural frequencies as a signature. However, these are dependent not only on the constitutive parameters of the target, but also on those of the surrounding medium. For frequencies above the relaxation frequency of the medium (the high-frequency window) and for the relative dielectric constant Er of the target (relative to the external medium) sufficiently ... |
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| A Figure of Merit for Transit-Time-Limited Time-Derivative Electromagnetic Field Sensors |
JAN 93 |
26 pages |
| Authors:
Carl E. Baum; PHILLIPS LAB KIRTLAND AFB NM
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| This note derives a sensitivity-bandwidth figure of merit for comparing the performance of sensors designed to measure the time derivative of D or B. This figure of merit is a dimensionless number combining sensitivity and upper frequency response (bandwidth) in a form equivalent area times the square of bandwidth. The larger the figure of merit A, the more efficient is the design. This figure of merit is appropriate where sensor ... |
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| The Single-Gap Hollow Spherical Dipole in Non-Conducting Media |
JAN 93 |
72 pages |
| Authors:
Carl E. Baum; PHILLIPS LAB KIRTLAND AFB NM
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| This note considers the response of a hollow spherical dipole in non- conducting media. This sensor is a sphere with a slot around the equator which is uniformly resistively loaded. The current through the resistive load across the slot is proportional to the time rate of change of the displacement vector for low frequencies. The response characteristics of such a device at high frequencies are calculated using expansions in spherical ... |
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| A Spiral-Transmission-Line Technique for Detecting Slot Apertures in Shield Enclosures |
31 DEC 87 |
12 pages |
| Authors:
Carl E. Baum; AIR FORCE WEAPONS LAB KIRTLAND AFB NM
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| This note presents another concept, SPIRA, for monitoring the integrity of a shield enclosure. In this concept a helically wound conductor is used as a transmission line in conjunction with the shield enclosure. This type of structure produces an external magnetic field with a strong component parallel to the axis of the helix. This allows the helix to lie parallel to potential slot apertures in the shield ... |
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| Monitor for Integrity of Doors in a Shield Enclosure |
25 NOV 87 |
16 pages |
| Authors:
Carl E. Baum; AIR FORCE WEAPONS LAB KIRTLAND AFB NM
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| This note extends the SCUTUM concept for monitoring the integrity of a shield enclosure. Arrays of loops are placed around (outside) the perimeter of a door which must open and close. Coaxial cables are used to reroute the transmission-line conductors (passing along the shield surface) around the door opening. (RH) |
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| Electromagnetic Pulse Interaction Notes-EMP 3-39. |
JUL 1979 |
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| Authors:
Carl E. Baum; AIR FORCE WEAPONS LAB KIRTLAND AFB NM
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 | This is a series of notes on electromagnetic pulse interaction. Subjects covered are: Electromagnetic Penetration Through a Circular Aperture in a Plane Screen Separating a Conducting Medium and Nonconducting Medium; Small Aperture on a Multiconductor Transmission Line Filled with Inhomogeneous Dielectrics; On the Electromagnetic Field Excitation of Unshielded Multiconductor Cables; A Coupling Model for a Pair of Skewed Transmission Lines; On the Analysis of General Multiconductor Transmission-Line Networks; Field Excitation ... |
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| Electromagnetic Pulse Interaction Notes -- EMP 3-38. |
MAY 1979 |
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| Authors:
Carl E. Baum; AIR FORCE WEAPONS LAB KIRTLAND AFB NM
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| This is a series of five notes on electromagnetic pulse interaction. Subjects covered in this volume are: electromagnetic shielding by advanced composite materials; fields in a rectangular cavity excited by a plane wave on an elliptical aperture; transient electromagnetic characterization of arbitrary conducting bodies through an aperture-perforated conducting screen; a comparison of stick model skin current predictions with scale model measurements for the E-4 and EC-135 aircraft; aperture excitation of ... |
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| Differential-Geometry Scaling Method for Electromagnetic Field and Its Applications to Coaxial Waveguide Junctions. |
MAR 1973 |
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| Authors:
Tse Chin Mo; Charles H. Papas; Carl E. Baum; CALIFORNIA INST OF TECH PASADENA ANTENNA LAB
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| A differential geometry scaling method, stemming from Baum's pioneering work, is thoroughly explored and developed for electromagnetic fields. This method creates a class of equivalent electromagnetic problems P each described by a complicated geometry and having a complicated medium from an electromagnetic problem P' described by a simple Cartesian geometry and having a simple medium. Application of this method to coaxial waveguide structures is examined with special emphasis. Various conditions ... |
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| A SCALING TECHNIQUE FOR THE DESIGN OF IDEALIZED ELECTROMAGNETIC LENSES. |
MAR 1968 |
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| Authors:
Carl E. Baum; CALIFORNIA INST OF TECH PASADENA ANTENNA LAB
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| A technique is developed for the design of lenses for transitioning TEM waves between conical and/or cylindrical transmission lines, ideally with no reflection or distortion of the waves. These lenses utilize isotropic but inhomogeneous media and are based on a solution of Maxwell's equations instead of just geometrical optics. The technique employs the expression of the constitutive parameters, epsilon and mu, plus Maxwell's equations, in a general orthogonal curvilinear coordinate ... |
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