摘要 :
The document is in four parts: (1) Formulation of the problem. (2) Modeling single circular stacked- patch antenna on spherical structures. (3) Modeling patch arrays on spherical structures. (4) Development of experimental model.
摘要 :
This report describes progress during the 5th quarter of this program and summarizes the current status of the research. Our primary technical activities this period emphasized the design, analyses, and documentation of representa...
展开
This report describes progress during the 5th quarter of this program and summarizes the current status of the research. Our primary technical activities this period emphasized the design, analyses, and documentation of representative high-performance FAWSEA and CAWSEA antennas suitable for designation as standard or recommended. The configurations described are scalable with wavelength.
收起
摘要 :
This report describes progress during the 7th quarter of this program and summarizes the current status of the research. Technical activities this period emphasized pursuit (still in progress) of recipes/scripts to guide engineers...
展开
This report describes progress during the 7th quarter of this program and summarizes the current status of the research. Technical activities this period emphasized pursuit (still in progress) of recipes/scripts to guide engineers in design of "Rotated Aperture Waveguide Sidewall-Emitting Antennas" (RAWSEAs). This configuration is important to address, because it features the lowest-profile of all the antennas under investigation here. However, SARA's handful of aperture-efficient RAWSEA designs to date have required time-consuming iterative numerical modeling to obtain configurations with predicted performance approaching a FAWSEA of similar aperture area. We are confident this can be improved and are working on "standard" designs and scripts for the RAWSEA, such as those we documented earlier for the (Flat) FAWSEA and (Curved) CAWSEA. Some of the challenges and possible solutions are discussed here.
收起
摘要 :
This report results from a contract tasking University of Zagreb as follows: The contractor will investigate simulation tools for analyzing single- curved and double-curved microstrip patch antennas. These tools will overcome a ke...
展开
This report results from a contract tasking University of Zagreb as follows: The contractor will investigate simulation tools for analyzing single- curved and double-curved microstrip patch antennas. These tools will overcome a key limitation in existing laboratory computer simulations, which are unable to approximate the electromagnetic characteristics of dual curvature conformal arrays.
收起
摘要 :
Several topics relating to conformal arrays have received detailed attention in the last few years. These topics include pattern synthesis, types of appropriate radiating elements, and their impedance and mutual coupling character...
展开
Several topics relating to conformal arrays have received detailed attention in the last few years. These topics include pattern synthesis, types of appropriate radiating elements, and their impedance and mutual coupling characteristics, and wide angle scanning of linear arrays located on planar and conical surfaces. In the present report, the computation of an exact element pattern is described. The report begins with the general expressions for two potential functions representing the modal fields of arbitrary apertures on a conducting cone. Expressions for the electric field components are then derived from the potential functions for circumferential and radial slots with particular slot excitations. The field expressions are the basis for a computer program which computes radiation patterns from both circumferential and radial slots. The appropriate approximations for the Legendre functions and the spherical Bessel functions used for their computations are summarized in this report. The computer program is a modification and extension of one described by Pridmore-Brown and has been executed on the IBM 370 computer system, now operational at the Hughes Aircraft Company. The program computes the special functions in DOUBLE PRECISION, thus giving the required accuracy of the computations.
收起
摘要 :
Contents: Conformal arrays in tactical missiles, RPVs, and aircraft; Polarization requirements for conformal arrays; Discussion of a symmetrical multibeam feed networks for circular arrays; Conical arrays, studies and experiment; ...
展开
Contents: Conformal arrays in tactical missiles, RPVs, and aircraft; Polarization requirements for conformal arrays; Discussion of a symmetrical multibeam feed networks for circular arrays; Conical arrays, studies and experiment; Surface ray analysis of conformal arrays; Flush mounted radiating elements for conformal arrays; Analysis of arrays on a conducting conical surface; Circular and cylindrical arrays; STAR - A conformal array technique for airborne application; Conformal antenna array configurations report; Some issues in the application of cylindrical arrays to radars.
收起
摘要 :
The work done investigates some unexplored degrees of freedom in microstrip antenna design with the goal of developing a modified substrate configuration with improved bandwidth and maintained radiation characteristics. Results in...
展开
The work done investigates some unexplored degrees of freedom in microstrip antenna design with the goal of developing a modified substrate configuration with improved bandwidth and maintained radiation characteristics. Results indicate that sectioned substrates can deliver increased impedance bandwidth. A closed-form circuit-based model is also developed to predict the performance of these new antenna structures. The modified substrate techniques developed here will be used along with loading and slot etching techniques studied previously to construct wideband planar antennas and arrays.
收起
摘要 :
An infinite array model is developed, which shows that there are only minor differences between the pattern of an element in a dielectric clad cylindrical array and that of an element in the corresponding planar array. This result...
展开
An infinite array model is developed, which shows that there are only minor differences between the pattern of an element in a dielectric clad cylindrical array and that of an element in the corresponding planar array. This result suggests that the coverage of a finite dimension array over a cylinder of large radius can be evaluated with good approximation by the means of a planar array model. The coverage of arrays in an infinite ground plane covered by dielectric is predicted by developing a model which takes into account several waveguide modes in matching the fields at the array aperture interface. This model does not require the inversion of large matrices in determining the mutual coupling between array elements, thus permitting the analysis of relatively large arrays. This model shows that no coverage in the endfire direction is obtainable from these structures. To achieve endfire coverage the dielectric sheet covering the array must be of finite dimension.
收起
摘要 :
Slot spiral antennas offer the possibility for very thin and conformal designs. This report covers the physical characteristic of a cavity- backed slot spiral, as well as the associated infinite balun and termination designs. The ...
展开
Slot spiral antennas offer the possibility for very thin and conformal designs. This report covers the physical characteristic of a cavity- backed slot spiral, as well as the associated infinite balun and termination designs. The report traces through the development and characteristics of a 6 inch and 18 inch version of the slot spiral. Simulations and measurements of various cavity-backed spirals are presented and used to optimize the antenna's computations. Several options for miniaturizing this design using capacitive and inductive loadings are also presented.
收起
