ANSERLIN. A Broad-Band, Low-Profile, Circularly Polarized Antenna

A technique is presented for improving the performance of low-profile, circularly polarized (CP) radiating-line antennas. The essential elements of the technique pertain to establishing a single traveling wave on an annular sector of conducting strip that is positioned parallel and close to a large conducting surface. The antenna is named the annular sector, radiating-line (ANSERLIN) antenna. Using this technique, the impedance bandwidth becomes so large that it no longer has any bearing on the operating bandwidth. Instead, the pattern shape and axial ratio become the factors that limit the bandwidth. Both senses of circular polarization can be transmitted or received from the same structure. Experimental results for two-port ANSERLIN antennas are presented. The method of exciting a traveling wave on the annular sector is discussed. Design parameters are given for an antenna that will produce a broadside axial ratio that is less than 0.5 dB at a specified frequenc

Power Division by Element Design in a Circularly Polarized, Series-fed Array

The feasibility of designing a wideband circular polarized (CP) array of series-fed elements using the element geometry to control the array excitation has been demonstrated. The simple array of wideband, low-profile CP elements requires no phase-shifters and only sufficient feed lines for the interconnection of the elements in a series-fed array. A complicated network is not required to obtain the excitation coefficients for a specified design. Rather, the excitation coefficients can be realized by utilizing the geometric parameters of the individual elements

The Synthesis of Patterns using a Series-Fed Array of Annular Sector Radiating Line (ANSERLIN) Elements: Low-Profile, Circularly Polarized Radiators

A series-fed, circularly polarized array of annular sector radiating-line elements that operates over a ground plane and has a low profile is presented. Pattern shaping can be achieved through control of the fraction of the incident power that is radiated by each element. This can be accomplished over a wide range by a simple adjustment in the geometry of each element. A synthesis technique is given, and experimental results are presented. The array is demonstrated to have a high return loss (good impedance match) and a low axial rati

Automation and Other Extensions of the SMAC Modal Parameter Extraction Package

As model validation techniques gain more acceptance and increase in power, the demands on the modal parameter extractions increase. The estimation accuracy, the number of modes desired, and the data reduction efficiency are required features. An algorithm known as SMAC (Synthesize Modes And Correlate), based on principles of modal filtering, has been in development for a few years. SMAC has now been extended in two main areas. First, it has now been automated. Second, it has been extended to fit complex modes as well as real modes. These extensions have enhanced the power of modal extraction so that, typically, the analyst needs to manually fit only 10 percent of the modes in the desired bandwidth, whereas the automated routines will fit 90 percent of the modes. SMAC could be successfully automated because it generally does not produce computational roots

A theory of metamaterials based on periodically loaded transmission lines: Interaction between magnetoinductive and electromagnetic waves

Published versio

Effects of transportation, handling and environment on slaughter cattle. I, Weight loss and carcass yield

Includes bibliographical references (page 11)