Photonics-based real-time ultra-high-range-resolution radar with broadband signal generation and processing

Real-time and high-resolution target detection is highly desirable in modern radar applications. Electronic techniques have encountered grave difficulties in the development of such radars, which strictly rely on a large instantaneous bandwidth. In this article, a photonics-based real-time high-range-resolution radar is proposed with optical generation and processing of broadband linear frequency modulation (LFM) signals. A broadband LFM signal is generated in the transmitter by photonic frequency quadrupling, and the received echo is de-chirped to a low frequency signal by photonic frequency mixing. The system can operate at a high frequency and a large bandwidth while enabling real-time processing by low-speed analog-to-digital conversion and digital signal processing. A conceptual radar is established. Real-time processing of an 8-GHz LFM signal is achieved with a sampling rate of 500 MSa/s. Accurate distance measurement is implemented with a maximum error of 4 mm within a range of ~3.5 meters. Detection of two targets is demonstrated with a range-resolution as high as 1.875 cm. We believe the proposed radar architecture is a reliable solution to overcome the limitations of current radar on operation bandwidth and processing speed, and it is hopefully to be used in future radars for real-time and high-resolution target detection and imaging.

[1]  K. Williams,et al.  An 8-18-GHz all-optical microwave downconverter with channelization , 2001 .

[2]  Mark A. Richards,et al.  Fundamentals of Radar Signal Processing , 2005 .

[3]  Lin Li,et al.  24GHz Software-Defined Radar System for Automotive Applications , 2007, 2007 European Conference on Wireless Technologies.

[4]  José Capmany,et al.  Microwave photonics combines two worlds , 2007 .

[5]  P. Shih,et al.  Optical Millimeter-Wave Signal Generation Using Frequency Quadrupling Technique and No Optical Filtering , 2008, IEEE Photonics Technology Letters.

[6]  Hongwei Chen,et al.  High-Spectral-Purity Millimeter-Wave Signal Optical Generation , 2009, Journal of Lightwave Technology.

[7]  V. R. Pagan,et al.  Linearized electrooptic microwave downconversion using phase modulation and optical filtering. , 2011, Optics express.

[8]  R. A. Minasian,et al.  Microwave Photonic Downconverter With High Conversion Efficiency , 2012, Journal of Lightwave Technology.

[9]  K. Williams,et al.  Microwave photonics , 2002 .

[10]  Taijun Liu,et al.  Mach-Zehnder: A Review of Bias Control Techniques for Mach-Zehnder Modulators in Photonic Analog Links , 2013, IEEE Microwave Magazine.

[11]  Hongwei Chen,et al.  A simple photonic generation of linearly chirped microwave pulse with large time-bandwidth product and high compression ratio. , 2013, Optics express.

[12]  Jianping Yao,et al.  Generation of Linearly Chirped Microwave Waveform With an Increased Time-Bandwidth Product Based on a Tunable Optoelectronic Oscillator and a Recirculating Phase Modulation Loop , 2014, Journal of Lightwave Technology.

[13]  Fabrizio Berizzi,et al.  A fully photonics-based coherent radar system , 2014, Nature.

[14]  S. Pan,et al.  Phase noise measurement of wideband microwave sources based on a microwave photonic frequency down-converter. , 2015, Optics letters.

[15]  Jianping Chen,et al.  Generation of a widely tunable linearly chirped microwave waveform based on spectral filtering and unbalanced dispersion. , 2015, Optics letters.

[16]  Filippo Scotti,et al.  Photonics in Radar Systems: RF Integration for State-of-the-Art Functionality , 2015, IEEE Microwave Magazine.

[17]  Shilong Pan,et al.  Satellite Payloads Pay Off , 2015, IEEE Microwave Magazine.

[18]  Jianping Chen,et al.  All-optical central-frequency-programmable and bandwidth-tailorable radar , 2016, Scientific Reports.

[19]  S. Pan,et al.  Linearly chirped microwave waveform generation with large time-bandwidth product by optically injected semiconductor laser. , 2016, Optics express.

[20]  Korkut Yegin,et al.  Predistorter based K-band FMCW radar for vehicle speed detection , 2016, 2016 17th International Radar Symposium (IRS).

[21]  Yuliang Qin,et al.  Experimental research on imaging of precession targets with THz radar , 2016 .

[22]  Guoqiang Zhang,et al.  Photonics-based broadband radar for high-resolution and real-time inverse synthetic aperture imaging. , 2017, Optics express.