Astigmatic Millimeter-Wave Focusing for Active Denial Depth of Field
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Solution Overview
Problem
Existing active denial systems using millimeter-waves face challenges in maintaining effective power density over a broad range of distances, with traditional focusing systems either requiring high peak power or being ineffective at close ranges due to converging or diverging beam intensity, which can lead to inadequate deterrence or tissue damage.
Innovation Solution
The implementation of an astigmatic focusing system that diverges in one direction and converges in another, maintaining a constant effective area and power density over a greater distance, and the ability to alternate between different focusing configurations to achieve peak power densities at various ranges with reduced total output power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a traditional focusing system converges the beam in both x and y directions, then the peak power density is increased at the focal point, but the depth of field is reduced and the beam becomes ineffective at close ranges
Solution Approach 1:
The patent applies asymmetry by using different focal lengths in the x and y directions (astigmatic focusing). The beam is focused to a line rather than a point, with the first focal length in one direction and the second focal length in the perpendicular direction, creating an elongated focal region that extends the depth of field while maintaining effective power density over a broader distance range.
Solution Approach 2:
The patent transitions from point focusing (zero-dimensional focus) to line focusing (one-dimensional focus) by introducing different focal lengths in orthogonal directions. This dimensional change in the focal region transforms the beam profile from a concentrated spot to an extended line, thereby increasing the depth of field while maintaining effective power density.
2Length of moving object
If a collimated beam is used instead of a focused beam, then the depth of field is increased, but the total output power required is increased significantly
Solution Approach 1:
The patent uses asymmetric focusing with different focal lengths in orthogonal directions to create a line focus. This astigmatic configuration allows the beam to maintain a more uniform power density over an extended distance range, achieving a deeper depth of field while requiring significantly less total output power compared to a collimated beam system.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the depth of field and reduces the total output power required to achieve effective power densities over a broader range, ensuring consistent deterrence without tissue damage across different distances.
Implementation Method 1
at least one beam-processing element comprising an astigmatic focusing system configured to direct a focused beam with a focusing profile in a plane defined by a x-axis and a z-axis that includes an axis of propagation, and a substantially different focusing profile in a plane defined by a y-axis and the z-axis
Data Source
AI summary
An active denial apparatus for use in non-lethal weaponry includes at least one focusing element configured to focus millimeter-wave energy along an axis of propagation. The at least one focusing element includes an astigmatic or dual axis focusing system configured to direct a focused beam that allows the active denial apparatus to accurately immobilize targets at both close and long range within acceptable limits of intensity.