Antenna Array Phase Shifters Using Square-Wave Beam Steering
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Solution Overview
Problem
Existing liquid crystal-based antenna systems face challenges in achieving symmetric 'turn on' and 'turn off' speeds, leading to asymmetric operational control, and require complex voltage supply systems for non-DFLC antennas, increasing complexity and cost.
Innovation Solution
The use of multi-frequency control of variable dielectric constant (VDC) material to control the orientation of liquid crystal domains in an antenna array, allowing for independent and rapid control of each radiator's dielectric constant through pulse width modulation (PWM) or frequency modulation, enabling faster response times and reduced complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional liquid crystal control is used with single frequency, then the system can operate with simpler control, but the response time is slow and asymmetric (turn on faster than turn off)
Solution Approach 1:
The patent applies periodic square wave signals at two different frequencies (first frequency for turn-on, second frequency for turn-off) to control the liquid crystal domains. This periodic action with frequency switching enables symmetric and faster response times by utilizing the dielectric anisotropy changes at different frequencies, resolving the asymmetry problem of conventional single-frequency control.
Solution Approach 2:
The patent changes the frequency parameter of the applied electrical signal to control liquid crystal domain orientation. By switching between first frequency (for horizontal alignment) and second frequency (for vertical alignment), the system achieves rapid and symmetric response times without increasing structural complexity.
2Adaptability or versatility
If non-DFLC antennas are used, then more voltage suppliers are needed to control each radiator, but this increases system complexity and cost
Solution Approach 1:
The patent makes a single voltage supplier universal by enabling it to output signals at multiple frequencies (first frequency and second frequency). This multi-functional voltage supplier controls all radiators in the array, eliminating the need for multiple voltage suppliers while maintaining full beam steering capability across the antenna array.
Solution Approach 2:
The patent segments the control signal into different frequency components (first frequency for horizontal polarization, second frequency for vertical polarization) that can be selectively applied to different radiators. This frequency-based segmentation allows a single voltage supplier to independently control multiple radiators, reducing system complexity.
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 enables faster and more symmetric control of liquid crystal domains, reducing response time and complexity, and allows for the creation of electronically-scanned antenna arrays with improved beam steering capabilities for satellite communication antennas.
Implementation Method 1
multi-frequency control of variable dielectric constant (VDC) material to control the orientation of liquid crystal domains
Implementation Method 2
When an external electric field is applied to the liquid crystal, the dipole molecules tend to orient themselves along the direction of the field
Implementation Method 3
an array of antenna elements, each having an associated delay line and a voltage-dependent difference in dielectric anisotropy
Data Source
Figure 1~3
Figure 4~5
Figure 6
AI summary
An antenna array is steered electronically by controlling the transmission speed of the RF signal in feed line of each radiator in the array. The transmission speed is controlled using phase shifters, that include variable dielectric constant (VDC) material causing the change in transmission speed. The control signal applied to the VDC material generates the required phase shift. The control signal is calculated for each phase shifter in real time for each control cycle, so as to enable the main beam to track a target, such as a satellite. The control signal is a square wave signal, and each control signal has a specifically calculated duty cycle or frequency to generate the required phase shift.