Radar detection method and device based on microwave photon frequency multiplication and orthogonal demodulation

Abstract

The invention discloses a radar detection method based on microwave photon frequency multiplication and orthogonal demodulation. The method includes: modulating an intermediate-frequency linear frequency modulation signal onto an optical carrier to generate a reservation carrier and a modulation optical signal of a unilateral second-order sideband; dividing the modulation optical signal into two branches, and emitting one optical signal after being converted into an electrical signal and serving as a radar detection signal to a target; using a target echo signal to perform electro-optical modulation on the optical carrier to acquire an optically loaded echo signal; taking the other modulation optical signal as a reference optical signal to perform orthogonal demodulation on the optically loaded echo signal to acquire two orthogonal intermediate-frequency signals carrying target information, and extracting the target information from the orthogonal intermediate-frequency signals. The invention further discloses a radar detection device based on microwave photon frequency multiplication and orthogonal demodulation. The radar detection device has the advantages of both microwave photon technology and orthogonal demodulation and is simple in realization structure and high in detection efficiency.

Description

technical field [0001] The invention relates to a radar detection method, in particular to a radar detection method and device based on microwave photon frequency doubling and quadrature demodulation. Background technique [0002] All-weather, real-time and high-resolution radar detection, imaging and identification of targets have important applications in both military and civilian fields. However, the existing electronic radar systems are limited by "electronic bottlenecks", such as the limited operating bandwidth and nonlinearity of electronic devices, so that radar systems mostly work in fixed frequency bands with narrow bands (see [S.Scherr, S.Ayhan, M.Paoli, "Accuracy limits of a K-band FMCW radar with phase evaluation," 9th European Radar Conference (EuRAD), 2012]), which limits the detection resolution and adjustment flexibility of the radar system. In order to distinguish the polarity of the intermediate frequency signal, the amplitude and phase information of the...

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Problems solved by technology

However, the existing electronic radar systems are limited by "electronic bottlenecks", such as the limited operating bandwidth and nonlinearity of electronic devices, so that radar systems mostly work in fixed frequency bands with narrow bands (see [S.Scherr, S.Ayhan, M.Paoli, "Accuracy limits of a K-band FMCW radar with phase evaluation,"9th EuropeanRadar Conference(EuRAD),2012]), thus limiting the detection resolution and adjustment flexibility of the radar system

In order to distinguish the polarity of the intermediate frequency signal, the amplitude and phase information of the intermediate frequency signal must be obtained at the same time, that is, the quadrature demodulation technology is used in the radar receiver, but it is also limited by the bandwidth and nonlinearity of electronic technology, and electronic technology is very difficult under broadband conditions. It is difficult to achieve signal amplitude and phase matching in the demodulation process (see [A.Gunst, G.Kant, "Application of digital wide bandmismatch calibration to an I / Q receiver," IEEE International Symposium on Circuits and Systems, 2002.]), As a result, image frequency and spurious components appear in the intermediate frequency signal when the broadband radar adopts quadrature demodulation technology, which seriously affects the detection performance of the radar system

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