Tech Briefs

In-house antenna measurement laboratory enables cutting-edge radio frequency aperture research.

AFRL's Radiation and Scattering Compact Antenna Laboratory (RASCAL) enables researchers to develop and evaluate advanced aperture technologies that support electronic warfare, radar, communication, and navigation— technologies supplementing a variety of applications as the "eyes and ears" of the warfighter. Current research efforts are concentrated on developing relatively small and inexpensive broadband, multifunctional antennas, as well as conformal and structurally integrated antennas for manned and unmanned air vehicles. Using the RASCAL facility, researchers can perform the necessary fabrication, simulation, testing, and measurement of aperture technologies.

Figure 1. Rolled-edge reflector

RASCAL's fully in-house rapid prototyping capability alleviates the time and costs incurred from outsourcing jobs for breadboard antennas. Researchers create the majority of fabrications using a precision milling machine specifically manufactured for creating circuit board prototypes. This equipment plays an instrumental role in manufacturing many of the nontraditional antenna designs under development. The milling machine accepts a variety of input files, reducing the amount of time spent during the premanufacturing process. Its capabilities include full routing, as well as precision milling and drilling to trace width specifications as small as 0.1 mm on a variety of substrates. Further, researchers can custom-build supplementary hardware, such as mounts or casings, in the on-site prototype lab.

Researchers employ an assortment of computational electromagnetic tools both to simulate the characteristics of antennas under development and to forecast the performance of antennas installed on different platforms. Additionally, they continually develop and expand other tools to bridge the gap between research-grade analysis codes and production-grade code suites available for intuitive, rapid, and effective utilization in practical situations. Examples include rapidly installed antenna geometry tools, tools to migrate designs from prediction to analysis, and rendering tools to aid the antenna platform designer in total system analysis.

The advent of more powerful computer resources and codes that model antennas through numeric simulations have greatly enhanced the designer's ability to forecast device performance. Computer simulation in aperture design provides precise parametric studies (for sensitivity measurement and tolerance definition), as well as a means of concept demonstration for yet undeveloped structures and materials. This capability results in a more cost-effective, convenient engineering process.