Over the last three decades, intensive work has been done to develop techniques aimed at accurate and efficient analysis of antenna radome systems. Some applications involve radar operating in the millimeter wave range and for those cases the radome size can be on the order of one hundred wavelengths or so in length. For practical simulations of such large radomes, a hybrid physical optics-method of moments (PO-MoM) technique is presented for accurate and efficient analysis of electrically large radomes. The procedure combines the method of moments (MoM) for modeling the tip region of the dielectric radome and ray optics in conjunction with physical optics (PO) for treating the flatter smooth section of the radome. Calculated far-field patterns using the new technique agree well with measured data for a reflector antenna radiating in the presence of a large radome. The computational time for simulating the performance of a 46/spl lambda/ reflector in the presence of an 88/spl lambda/ long radome was a mere 4 h on a 233 MHz PC.

Hybrid PO-MoM analysis of large axi-symmetric radomes

Gaussian beams are used as basis elements in field representations. To gain insight into how the choice of beam parameters affects the final representation, a systematic study for the simple test case of a one-dimensional linearly phased cosine-aperture distribution has been undertaken. By successively adding individual displaced and/or tilted beams with large, narrow, or matched waists, one can assess how the elements in various portions of the lattice contribute to the build-up of the actual field in the aperture, near zone, and far zone. Adding enough beams always guarantees homing in on the exact solution, as is verified here by independent comparison. Different beam choices imply different modeling of the radiation process. The understanding gained thereby is helpful for selecting beam parameters in subsequent applications where it is necessary to balance requirements of good convergence, ease of computation, and ability to track the beams through perturbing environments like a radome. Indications are that the narrow beams provide the most robust and versatile formulation to deal with these generalized conditions. >

Systematic study of fields due to extended apertures by Gaussian beam discretization

The spectacular advancements in antenna technologies for control, guidance, surveillance, and communication applications for airborne platforms have resulted in the realization of novel conformal antenna arrays, embedded antenna systems on the body of the fuselage, and structurally integrated radiating systems. Such antenna systems/ radiating structures facilitate superior functional capabilities with reduced payloads, desirable for airborne applications. They demand novel airborne radome structures with superior electromagnetic (EM) performance characteristics. Furthermore, rapid progress in the fields of frequency-selective surfaces (FSS) and metamaterials has had significant impact on the development of radome technology. Since conventional EM design techniques, based on transmission-line models, may not be sufficient for such applications, new techniques, based on numerical methods, have been developed. In order to circumvent the limitations of conventional low-frequency/high-frequency methods in analyzing antenna-radome interaction phenomena, hybrid methods, in conjunction with novel algorithms, are currently used. Considering the significant growth in EM technologies for airborne radome applications, the objective of this paper is to provide a glimpse of the techniques/methods for the EM design and analysis of airborne radomes. Some of the challenging EM issues/problems pertaining to airborne radome development are also discussed, which may be of interest to the radome community in the aerospace sectors.

Electromagnetic Design and Performance Analysis of Airborne Radomes: Trends and Perspectives [Antenna Applications Corner]

By assigning complex values to the source coordinates and pulse-initiation time of the time-dependent Green function in free space, one may generate a field solution that behaves like a propagating pulsed beam. Although the conventional pulsed line source response is known in closed form, the complex extension cannot be performed directly thereon because of the nonanalytic behavior of the causal field. The analytic continuation is carried, out here by spectral analysis and synthesis, utilizing the recently formulated spectral theory of transients. This approach not only guarantees uniqueness but also elucidates the spectral content of the resulting waveform, which is composed of contributions from singularities in the complex spectral wave-number plane. By similar analytic extension of time-dependent Green functions for more complicated environments, one may construct directly the transient field produced in these environments by the incident pulsed beam.

Spectral analysis of complex-source pulsed beams

Gaussian-beam reflection and transmission in the presence of a convex circular boundary separating two different dielectrics is analyzed by the complex ray method whereby rays are traced in a complex coordinate space from the complex source point to the complex extension of the interface and then to the real observation point. The search for the complex parameters describing the ray connecting the source and the observer can be numerically time consuming. Much more efficient are paraxial approximations that express the field as perturbations about its values on the axis of maximum strength. Such paraxial approximations are explored here, using on-axis complex ray and even on-axis real ray solutions with corrections accounting for differences in phase, ray reflection and transmission coefficients, and ray divergence coefficients. Extensive numerical comparisons establish a reasonable range of validity of both paraxial approximations, except in regions characterizing the transition to total reflection, if that can occur.

Reflection and transmission of beams at a curved interface

Assessment of the radiation characteristics of certain types of radome covered antennas poses the problem of transmission of amplitude tapered large-aperture fields through a curved dielectric layer. Modeling the amplitude taper by a Gaussian, the incident illumination can be generated by a source at a complex coordinate location. The radome problem is then addressed by tracing complex ray fields from the complex source point through the complex extension of the radome configuration to the real location of the observer. No integrations over equivalent apertures are required here. The complex ray tracing has been performed for conventional complex geometric trajectories as well as more accurate trajectories with lateral shifts at the radome interfaces, and takes into account multiple reflections inside the radome. As previously for real rays, the multiple internally reflected complex rays can be combined into a "collective ray" that is weighted with a curvature and (or) taper corrected slab transmission coefficient. Numerical calculations for various two-dimensional circular cylindrical and wedge-tapered prototypes and various beam illuminations demonstrate the feasibility of the complex ray method, the efficiency of the collective ray concept, and the adequacy of the ray model without lateral shifts for the radome application.

Complex ray analysis of beam transmission through two-dimensional radomes

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

X. Gao

Author Tools

Chat about Author

Papers

Complex ray analysis of beam transmission through two-dimensional radomes