РАДИОФОТОННЫЙ МЕТОД ОПРЕДЕЛЕНИЯ УГЛА ПРИХОДА ОТРАЖЁННОГО РАДИОЛОКАЦИОННОГО СИГНАЛА НА ОСНОВЕ ТАНДЕМНОЙ АМПЛИТУДНО-ФАЗОВОЙ МОДУЛЯЦИИ
Authors: Морозов О.Г. , Морозов Г.А. , Ильин Г.И. , Нуреев И.И. , Сахабутдинов А.Ж. , Ростокин И.Н. , Иванов А.А. , Лустина А.А. , Денисенко Е.П. , Денисенко П.Е. , Андреев В.Д. 
Published: February 2025

В статье рассмотрен новый, радиофотонный подход для измерения угла прихода (УП) радиолокационного микроволнового сигнала, отражённого от движущегося объекта. Для его обработки в оптическом диапазоне используется блок электрооптических модуляторов, который в отличие от известных решений выполнен на тандемных однопортовых амплитудном и фазовом модуляторах. Измеритель имеет очень простую структуру и невысокую стоимость, характеризуется широким диапазоном рабочих частот в десятки ГГц и имеет высокую надёжность работы, обусловленную простой процедурой калибровки и контроля температурных режимов элементов, тем более, если он изготовлен на базе интегральных фотонных схем. Экспериментальные результаты показывают, что измерение УП в диапазоне от 0 до π/2 возможно с погрешностью менее ±1,7 мрад при определении мощности информативной компоненты на частоте отражённого сигнала с погрешностью ± 10-3.

Introduction. Paper presents a novel approach that is based on radio photonics technologies and aims at measuring the angle-of-arrival (AoA) of a microwave radar signal reflected from a moving object. The application of radiophotonics ensures the most important benefits of the method, such as a wide instantaneous bandwidth and immunity to electromagnetic interferences during the measurements, as well as implementation advantages - the small size and light weight of the AoA measuring tools. The aim of the workis to present and experimentally prove the new radiophotonic AoA measuring tool. The principle behind measuring tool. AoA measuring tool has the same structure as a classical fiber-optic communication channel and consists of a laser, a block of electro-optical modulators and a photodetector. To process the microwave echo signal in the optical range, there is used a block of electro-optical modulators, which, in contrast to the known solutions based on a two-port Mach-Zehnder amplitude modulator, consists of two parallel subunits that are built on the single-port tandem amplitude-phase modulators (TAPM). A microwave echo signal with a time delay, defined by the AoA is sequentially fed to the radio frequency inputs of TAPMs through the connected receive antennas. The components of the laser carrier at the both TAPM outputs are suppressed, which stands out the proposed solution from the known ones in terms of higher measurement accuracy. The beats of the TAPM output signals at the photodetector output represent a converted echo signal which power is used to yield AoA. Thus, the measuring tool has a very simple structure and low cost, has a wide operating frequency range, defined by the bandwidth of modulators and photodetectors. Another advantage is a high reliability due to a simple procedure of calibrating and monitoring the temperature regimes of the elements, especially if the tool is made on the basis of integral photonic schemes. Findings.Experiments showed that the AoA can be measured with an error less than ± 1.7 mrad in the range from 0 to π/2 if the power of the informative component is measured at the echo signal frequency with an error of ± 10-3.