Directional RF Waveguide Antenna with Movable Bottom Beam Scanning
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Solution Overview
Problem
Existing directional antennas, particularly in the HF frequency band, are complex and expensive due to the need for numerous phase shifters and bulky quasi-optical devices, which are inefficient and often limited to circular orientations, while slot guide antennas require frequency modifications incompatible with other radio chain requirements.
Innovation Solution
A directional antenna array with a movable bottom part of the waveguide allows for beam direction control without electronic phase shifters or optical systems, using a waveguide with a movable bottom part to adjust the height and thus the wavelength, allowing for precise beam orientation in multiple planes without altering the frequency or requiring mechanical movement of the RF source.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If passive electronically scanned antennas (PESA) or active electronically scanned antennas (AESA) are used to direct the radiation beam without mechanical intervention, then beam direction control is achieved, but the device complexity and cost increase due to requiring thousands of phase shifters to be controlled simultaneously
Solution Approach 1:
The patent extracts the phase shifting function from individual antenna elements and consolidates it into a single mechanical degree of freedom. By removing the need for N phase shifters and replacing them with one movable bottom wall, the system achieves beam scanning while dramatically reducing device complexity and cost.
Solution Approach 2:
The patent replaces the electronic phase shifter system with a mechanical translation system. The bottom wall of the waveguide is translated along the z-axis to change the effective electrical length of the cavity, thereby controlling the beam direction mechanically instead of electronically.
2Ease of operation
If quasi-optical devices with lenses or mirrors are used to direct the antenna beam, then beam direction can be controlled, but the devices become bulky and inefficient
Solution Approach 1:
The patent eliminates the need for external lenses, mirrors, or quasi-optical components by integrating the beam steering function directly into the waveguide structure. The bottom wall translation mechanism provides beam direction control without requiring bulky external optical elements.
3Ease of operation
If rotation-based VICTS devices with superimposed plates are used to deflect the beam in azimuth and elevation, then beam direction control is achieved, but the device remains bulky and can only address circular antennas
Solution Approach 1:
Instead of rotating plates to deflect beams, the patent inverts the approach by translating the bottom wall to change the effective cavity length. This non-rotational mechanism works with rectangular waveguides and eliminates the bulk associated with rotation-based VICTS devices.
4Ease of operation
If slotted guide type antennas modify the frequency to change the beam direction, then beam direction control is achieved, but the frequency modification is incompatible with the rest of the radio chain
Solution Approach 1:
The patent introduces a dynamic mechanical element (movable bottom wall) that changes the effective electrical length of the waveguide cavity. This dynamic adjustment of physical dimensions allows beam steering without changing the operating frequency, maintaining compatibility with the radio chain.
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 solution enables the control of multiple phased antennas with reduced complexity and cost, providing efficient beam orientation in one or two dimensions without the need for active phase shifters or bulky components, enhancing directional control and gain while maintaining frequency stability.
Implementation Method 1
a directional antenna array with a movable bottom part of the waveguide allows for beam direction control without electronic phase shifters or optical systems, using a waveguide with a movable bottom part to adjust the height and thus the wavelength
Data Source
Figure 1A~1B
Figure 2A~2B
Figure 3a~3b
AI summary
The invention relates to a directional antenna array, a radio frequency antenna comprising one or more directional arrays, directional in one or two dimensions, a method for pointing the radio frequency antenna, and the associated computer program. The directional antenna array according to the invention comprises: - a rectangular waveguide (101) extending along a longitudinal axis (Oy), and comprising: ∘ a fixed portion with two lateral faces and a top face, and ∘ a bottom piece; - a plurality of radiating elements (102) arranged on the fixed portion of the waveguide. The bottom piece of the rectangular waveguide is movable in translation along a direction of displacement (Oz) parallel to the lateral faces, the maximum distance between the bottom piece and the top face being less than the distance between the lateral faces.