Active Reflector Oscillation Inhibition via Phase Shifting
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Solution Overview
Problem
Active reflectors in radar systems often exhibit self-induced oscillation due to self-interference, which can render them unresponsive and cause interference to surrounding radar sensors.
Innovation Solution
The implementation of an active reflector apparatus and method that includes an amplifier and an adjustable phase shifter to modify the phase of the transmit signal relative to the receive signal, thereby inhibiting oscillation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If active reflectors are implemented with adequate gain factors to enhance reflected wave energy, then radar detection range and visibility of small vehicles are improved, but self-induced oscillation occurs due to self-interference feedback
Solution Approach 1:
The patent converts the harmful self-interference feedback into a beneficial control mechanism by using the same feedback path to detect oscillation conditions and trigger corrective phase shifting, thereby transforming the source of harm into the means of prevention
Solution Approach 2:
The patent dynamically changes the phase parameter of the transmit signal to prevent oscillation. By adjusting the phase relationship between transmit and receive signals, the system maintains adequate gain for detection while avoiding the feedback conditions that cause self-induced oscillation
2Power
If amplifier gain is increased to improve detection of small vehicles, then reflected wave energy is enhanced, but self-interference causes oscillation that makes the reflector unresponsive
Solution Approach 1:
The patent implements a feedback mechanism that monitors the receive signal for oscillation conditions and automatically adjusts the phase shifter to correct the issue, allowing the system to maintain high power output while ensuring continued responsiveness through automatic correction
Solution Approach 2:
The patent introduces dynamic phase adjustment capability that allows the system to adapt its operating parameters in real-time based on detected conditions, transitioning from a static high-gain configuration to a dynamically controlled system that maintains both power and responsiveness
3Length of stationary object
If active reflectors re-transmit amplified signals to improve visibility, then detection range is extended, but interference is presented to surrounding radar sensors
Solution Approach 1:
The patent changes the phase parameter of the re-transmitted signal to prevent oscillation buildup, thereby allowing extended detection range while reducing the harmful interference effects that would otherwise be generated by oscillating reflectors
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 effectively prevents self-induced oscillation, ensuring the active reflector remains responsive and minimizes interference with other radar systems, while also enhancing the radar detection range and visibility of small vehicles.
Implementation Method 1
The amplifier amplifies a receive signal to generate a transmit signal
Implementation Method 2
The adjustable phase shifter modifies the phase of the transmit signal relative to that of the receive signal to inhibit oscillation
Implementation Method 3
Radar is an object-detection system that uses radio waves to determine the range, angle, or velocity of objects. A radar system consists of a transmitter producing electromagnetic waves, a transmitting antenna, a receiving antenna and a receiver. Radio waves from the transmitter reflect off an object and return to the receiver
Data Source
AI summary
Disclosed active reflector apparatus and methods that inhibit self-induced oscillation. One illustrative apparatus embodiment includes an amplifier and an adjustable phase shifter. The amplifier amplifies a receive signal to generate a transmit signal, the transmit signal causing interference with the receive signal. The adjustable phase shifter modifies the phase of the transmit signal relative to that of the receive signal to inhibit oscillation. A controller may periodically test a range of settings for the adjustable phase shifter to identify undesirable phase shifts prone to self-induced oscillation, and may maintain the phase shift setting at a value that inhibits oscillation.