Adjustable Phase Shifter in Air-Filled Coaxial Feeding Network
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Solution Overview
Problem
Base station antennas with variable tilt angles suffer from significant loss in the internal feeding network and phase shifters, limiting their gain and performance.
Innovation Solution
The integration of an adjustable differential phase shifter with a dielectric part that moves within the coaxial lines to vary the relative phase of signals, reducing losses and enhancing antenna gain.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If small-dimension coaxial cables are used in the feeding network to enable manual bending and reduce cost, then ease of manufacture and device flexibility are improved, but signal loss increases significantly
Solution Approach 1:
The patent replaces the traditional mechanical coaxial cable system with a waveguide-based feeding network. Instead of using flexible coaxial cables that cause signal loss, the invention uses rigid or semi-rigid waveguide structures that guide electromagnetic waves with much lower attenuation, thereby substituting a mechanical cable system with an electromagnetic waveguide system that eliminates the bending-loss tradeoff.
Solution Approach 2:
The patent changes the fundamental parameter of the transmission medium from coaxial cable to waveguide structure. This parameter change transforms the transmission characteristics, enabling low-loss signal transmission while maintaining the ability to achieve desired mechanical configurations through alternative means such as modular waveguide sections or flexible waveguide designs.
2Device complexity
If microstrip or stripline phase shifters with small conductor dimensions are used to achieve phase shifting, then device complexity is reduced, but resistive losses increase
Solution Approach 1:
The patent replaces microstrip or stripline phase shifters with waveguide-based phase shifting mechanisms. Instead of using planar transmission lines with small conductors that suffer from skin effect and resistive losses, the invention employs waveguide structures where electromagnetic waves propagate with lower attenuation, substituting the planar conductor system with a three-dimensional waveguide system.
Solution Approach 2:
The patent may employ composite material structures in the waveguide phase shifters, combining different materials with complementary properties to achieve low-loss phase shifting. This could include using high-conductivity materials for waveguide walls, dielectric materials with low loss tangents for phase control elements, or composite structures that optimize both electrical performance and mechanical properties.
3Volume of moving object
If the feeding network and phase shifter are integrated into a compact structure, then device volume is reduced, but signal loss increases due to smaller conductor dimensions
Solution Approach 1:
The patent integrates the phase shifter components within the waveguide structure itself, nesting the phase control mechanisms inside the waveguide pathway. This nesting approach allows compact integration without requiring separate small-dimension transmission lines, as the phase shifting is achieved by modifying the electromagnetic field distribution within the existing waveguide volume rather than adding separate lossy components.
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 results in higher antenna gain, increasing the range, capacity, and quality of service for base stations while reducing operational costs.
Implementation Method 1
The phase shift is achieved by moving a dielectric part that is located between the inner conductor and the outer conductor of the coaxial lines. It is a known physical property that introducing a material with higher permittivity than air in a transmission line will reduce the phase velocity of a wave propagating along that transmission line.
Data Source
AI summary
Antenna arrangement for a multi-radiator base station antenna, the antenna having a feeding network based on air filled coaxial lines (1, 2, 3), wherein each coaxial line comprises an outer conductor (8) and an inner conductor (4, 5, 6), wherein an adjustable differential phase shifter including a dielectric part (9) is arranged in the antenna and said dielectric part being movable longitudinally in relation to at least one coaxial line (1, 2, 3).