Optically Controlled Phased Array Radar Transmitter
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional phased array radar systems are limited by the 'aperture effect', restricted bandwidth, and high phase noise, which hinder radar bandwidth, resolution, and detection capabilities, especially at deviated frequencies where phase noise conceals returned signals.
Innovation Solution
A wholly optically controlled phased array transmitter integrating tunable optoelectronic oscillators and optical time delay networks based on multi-wavelength optical sources, utilizing a network of wavelength division multiplexers, splitters, modulators, amplifiers, and photoelectric detectors to generate and process microwave signals, eliminating the need for external microwave sources and reducing phase noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional electronically controlled phased array radar is used, then the system structure is relatively simple, but the radar bandwidth is limited due to the aperture effect
Solution Approach 1:
The patent replaces traditional electronic control mechanisms with optical control mechanisms. Specifically, it uses optical true time delay networks and optoelectronic oscillators to generate and control microwave signals, substituting electronic phase shifters and time delay devices with their optical counterparts. This substitution enables broadband operation while maintaining phased array functionality.
Solution Approach 2:
The patent introduces optical signals as an intermediary to bridge the gap between electronic radar components and broadband signal generation. Optical true time delay networks use light to delay microwave signals without the aperture effects that limit electronic systems, enabling extended bandwidth while the optoelectronic oscillator converts optical frequencies to microwave frequencies for radar transmission.
2Reliability
If traditional phased array radar is used, then the system is easier to operate, but phase noise is high which conceals returned signals at deviated frequencies
Solution Approach 1:
The patent replaces electronic signal generation and control with optical-based systems. The optoelectronic oscillator generates microwave signals with significantly reduced phase noise compared to traditional electronic oscillators, enabling detection of weak returned signals at deviated frequencies. The optical control system replaces electronic beam forming and time delay mechanisms that contribute to phase noise.
3Reliability
If optically controlled phased array radar with multi-wavelength sources is used, then instantaneous bandwidth is large and phase noise is low, but system complexity increases
Solution Approach 1:
The patent merges the functions of multiple wavelength sources, optical true time delay networks, and optoelectronic oscillators into an integrated optical control system. By combining these components, the system achieves broadband operation with low phase noise while reducing the number of separate subsystems needed compared to traditional approaches.
Solution Approach 2:
The patent creates a multi-functional optical control system where the same optical true time delay network and optoelectronic oscillator serve multiple purposes: generating microwave signals, providing time delay for beam forming, and enabling broadband operation across multiple frequencies. This multi-functionality reduces overall system complexity despite the advanced technology used.
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 a compact, cost-effective system with large instantaneous bandwidth, low phase noise, and frequency tunability, enhancing radar performance by generating broadband-tunable microwave signals and reducing system complexity.
Implementation Method 1
corresponding carrier signals and modulated signals generated by the microwave signal generator are electro-optically transformed via a modulator
Implementation Method 2
passed through a delay network structure, transformed from optical signals to electric signals via an optoelectronic detector
Data Source
Figure 1~3
Figure 4~5(b)
AI summary
A wholly optically controlled phased array transmitter with integration of tunable optoelectronic oscillators and optical time delay networks based on multi-wavelength optical sources and optical true time delay units, comprises: a multi-wavelength optical source, a first wavelength division multiplexer, a first optical splitter, a first electro-optic modulator, a second optical splitter, a first optical amplifier, a first optical time delay network, a photoelectric detector, an electric amplifier, a DC break, a second electro-optic modulator, a second optical amplifier, a second optical time delay network, an optical combiner, a second wavelength division multiplexer, a length of optical fiber, a photoelectric detector array, a transmitting and receiving component array, a microwave antenna array, a 1×2 optical switch, a 2x2 optical switch, a circulator, a third wavelength division multiplexer, a precise length of optical fiber, and a faraday rotation mirror. The present invention has the advantages of being ultra wideband and having no aperture effect of an optically controlled phased array radar, in addition to being capable of working under different microwave frequencies and of quick frequency hopping, plus structure compactness and low cost.