Phased Array Antenna Beam Correction for Stable Satellite Links
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Solution Overview
Problem
Existing phased array antenna systems for satellite communications on mobile objects face power reduction issues due to errors in sensor information and antenna directivity, leading to unstable communications, especially with high-frequency systems requiring large antennas and narrow beam widths, and existing solutions involve complex hardware and greater power fluctuations.
Innovation Solution
A phased array antenna device comprising multiple subarrays with phase shifters and a controller that calculates and applies direction-correction phase shift values to optimize signal power, allowing for stable satellite communication by adjusting the beam direction based on signal power and carrier-to-noise ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If beam scanning is used to direct the antenna toward the satellite based on sensor information, then satellite tracking is achieved, but power reduction in received signals occurs due to errors in sensor information or antenna directivity
Solution Approach 1:
The patent implements a feedback mechanism where the received signal power is continuously monitored and used to adjust the beam direction. The controller calculates the derivative of the received power with respect to beam direction and uses this information to iteratively optimize the beam pointing direction, compensating for errors in sensor information or antenna directivity without requiring complex additional hardware
Solution Approach 2:
The patent replaces complex mechanical feedback systems (such as those described in Patent Literature 1 requiring dedicated feedback signal generation hardware) with a computational approach. The feedback function is achieved through software-based optimization algorithms that process the received signal power information to adjust phase shifter settings, eliminating the need for separate feedback signal generation hardware
2Reliability
If high frequency systems with large antennas and narrow beam widths are used, then antenna performance is improved, but power reduction in received signals increases due to narrow beam width and sensitivity to directional errors
Solution Approach 1:
The patent makes the beam direction dynamic by continuously optimizing it based on real-time received power measurements. Instead of relying on static, pre-calibrated beam directions that are sensitive to errors, the system dynamically adjusts the beam pointing direction to track the maximum received power, thereby maintaining optimal performance despite the narrow beam width inherent in high-frequency systems
3Power
If feedback systems with dedicated hardware for generating feedback signals are implemented, then power reduction is compensated, but device complexity and cost increase
Solution Approach 1:
The patent makes the existing phase shifters and controllers perform multiple functions: they not only control the beam direction for satellite tracking but also serve as the feedback mechanism for optimizing received power. The same hardware components are used for both primary tracking function and power optimization, eliminating the need for dedicated feedback signal generation hardware described in Patent Literature 1
Solution Approach 2:
The system uses its own received signal power information to automatically optimize its performance. The controller monitors the received power and autonomously adjusts the phase shifter settings to maximize signal strength, making the system self-correcting without requiring external feedback hardware or complex additional components
4Measurement precision
If peak search of C/N ratio is performed for satellite tracking, then satellite acquisition is achieved, but greater power fluctuations occur with larger antenna size and smaller beam width, causing less stable communications
Solution Approach 1:
The patent applies preliminary optimization by continuously adjusting the beam direction based on received power measurements even during the satellite acquisition process. This preliminary optimization of beam pointing, performed in conjunction with the C/N ratio peak search, reduces power fluctuations and stabilizes communications before final acquisition is complete
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
The solution enables stable satellite communications by simply correcting the beam direction to maximize signal power, reducing power fluctuations and system complexity, thereby enhancing communication stability.
Implementation Method 1
Each of the plurality of phase shifters shifts phase of signal received by the corresponding antenna element with set phase shift value
Data Source
AI summary
A phased array antenna device for receiving a signal from a satellite includes subarrays including antenna elements and phase shifters that shift phases of signals received by the antenna elements with set phase shift values, a demodulator that demodulates the signals from the satellite with the phases shifted by the phase shifters and outputs the demodulated signals, and a controller that sets the phase shift values of the phase shifters and controls a beam direction. The controller calculates, for each of the subarrays, a direction-correction phase shift value that maximizes a power value of the signal from the satellite by being added to the phase shift values of the phase shifters included in the subarray and adds the direction-correction phase shift value to the phase shift values of the phase shifters included in the subarray.