Compact Antenna Beamforming Network Using Cross Couplers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-frequency antenna systems face significant signal attenuation and bulk management challenges due to the use of traditional coaxial cables, which are inadequate for frequency bands above 15 GHz, and rigid waveguide technology complicates isolength and size management.
Innovation Solution
A compact antenna beamforming network utilizing a network of cross couplers with equal-length input and output waveguides, arranged in a specific geometric configuration to maintain constant electrical paths and minimize size, addresses the challenges by using cross couplers to efficiently route signals to antenna sub-arrays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If traditional coaxial cables are used to connect Butler matrices to antenna sub-arrays, then flexibility and ease of connection are improved, but signal attenuation becomes excessive at frequencies above 15 GHz
Solution Approach 1:
The patent replaces the mechanical coaxial cable transmission system with a waveguide-based transmission system. Waveguides use electromagnetic wave propagation through hollow metallic structures instead of coaxial conductors, providing lower attenuation at high frequencies while maintaining rigid structural connections.
Solution Approach 2:
The invention changes the transmission medium parameters by transitioning from coaxial cable geometry to waveguide geometry. This parameter change enables efficient signal transmission at Ka-band frequencies by utilizing the waveguide's superior high-frequency characteristics, including lower skin effect losses and reduced radiation losses.
2Loss of energy
If rigid waveguide technology is used instead of coaxial cables, then signal attenuation is reduced at high frequencies, but isolength management and overall antenna size become more complex
Solution Approach 1:
The patent transitions from two-dimensional planar arrangements to three-dimensional spatial configurations by stacking Butler matrices vertically. This dimensional change allows waveguides to connect inputs and outputs through the third dimension, achieving equal path lengths more easily and reducing the overall footprint of the antenna system.
Solution Approach 2:
The invention implements a nested configuration where multiple Butler matrices are stacked vertically, with each matrix positioned at different heights. The waveguides are routed through the intermediate spaces between stacked matrices, creating a compact nested structure that efficiently manages connections while maintaining equal isolengths.
3Ease of manufacture
If linear Butler matrices with all inputs and outputs on opposite sides are used, then manufacturing is simplified, but isolength cannot be respected when connecting to antenna sub-arrays arranged around a cone
Solution Approach 1:
The patent resolves the isolength problem by utilizing the vertical dimension created by stacking matrices. Instead of requiring all inputs and outputs to lie in the same plane, the vertical stacking allows waveguides to reach antenna sub-arrays at different angular positions while maintaining equal path lengths through three-dimensional routing.
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 efficient signal routing while respecting isolength constraints and minimizing the overall size of the antenna, particularly effective in high-frequency bands like Ka-band, ensuring reliable communication without excessive signal loss.
Implementation Method 1
a number, equal to the number of inputs, of input waveguides, rigid, of equal length between them, connected at one end to the said inputs of the network of couplers and intended to receive, to their opposite free ends, a power supply signal and a number, equal to the number of outputs, of output waveguides, rigid, of equal length between them
Implementation Method 2
a network of cross couplers comprising two opposite groups of a number K of paired inputs and two opposite groups of a number K of paired outputs
Data Source
Figure 1~2
Figure 3
Figure 4a~4b
AI summary
The network (600) has a set of superimposed elements (631-633), and a network of cross-couplers (601-604) comprising two opposite groups of paired entries. A set of lengths of waveguides of each of the set of superimposed elements is arranged such that a wave enters electric path. A free end of each of the set of waveguides is connected to an output (614), and constant data is provided for all superimposed elements. Each cross-coupler of the superimposed elements is turned at a predetermined angle with regard to couplers of an immediate lower superimposed element. An independent claim is also included for an antenna network.