Abstract:In order to test and verify radar based systems for advanced driver assistance systems (ADAS), radar target simulators offer a test environment for reproducible dynamic automotive scenarios. This article presents a system capable of generating multiple targets with individual ranges and velocities for chirp-sequence frequency modulated continuous waveform (CS-FMCW) radars. The novel approach allows to generate targets without prior knowledge about the radar sensor by estimating the radar's waveform parameters.… Show more
“…With the usage of ACTs, this requirement may be overcome. ACTs are used widely in radar target simulators [25], [26] to evaluate radar systems and to simulate not only different distances but also different velocities of targets [27]. Unlike passive targets, this allows target detection for ACTs through preset velocities.…”
Section: B Calibration Concept With An Active Calibration Targetmentioning
To enhance the capabilities of high-resolution imaging or beamforming, the trend goes towards arrays with high-channel count and large aperture sizes. The operation at increasing mm-wave frequencies exacerbates the consequences of manufacturing tolerances on the array performance, further necessitating the development of high-quality calibrations. Thereby, a large number of array response vectors, addressed in the following as data points, is stored. Typically, one data point is measured at a time for each angle. To reduce the calibration effort, hereby defined as the number of required measurements, a calibration setup employing active calibration targets (ACT) is proposed. This setup allows the storage of a multitude of data points within a single measurement. In addition, this measurement setup is placed in the near-field of the array to relax the requirements on the size of the anechoic chamber. Employing multiple targets makes it challenging to compensate the near-field effects. Therefore, methods are discussed to ensure a consistent quality of the calibration considering the near-field influences from the ACTs. Exemplary measurements deploying an antenna array operating at 78.5 GHz demonstrate that this calibration measurement setup employing three ACTs placed in the near-field of the array reduces the calibration effort by a factor of 3 compared to state-of-the-art setups. The average deviation of the antenna phase relations amounts to 4.1 degree, proving that the presented setup achieves the same calibration quality as state-of-the-art setups.INDEX TERMS calibration, direction-of-arrival (DoA) estimation, imaging radar, MIMO radar, phased arrays, radar measurements.
“…With the usage of ACTs, this requirement may be overcome. ACTs are used widely in radar target simulators [25], [26] to evaluate radar systems and to simulate not only different distances but also different velocities of targets [27]. Unlike passive targets, this allows target detection for ACTs through preset velocities.…”
Section: B Calibration Concept With An Active Calibration Targetmentioning
To enhance the capabilities of high-resolution imaging or beamforming, the trend goes towards arrays with high-channel count and large aperture sizes. The operation at increasing mm-wave frequencies exacerbates the consequences of manufacturing tolerances on the array performance, further necessitating the development of high-quality calibrations. Thereby, a large number of array response vectors, addressed in the following as data points, is stored. Typically, one data point is measured at a time for each angle. To reduce the calibration effort, hereby defined as the number of required measurements, a calibration setup employing active calibration targets (ACT) is proposed. This setup allows the storage of a multitude of data points within a single measurement. In addition, this measurement setup is placed in the near-field of the array to relax the requirements on the size of the anechoic chamber. Employing multiple targets makes it challenging to compensate the near-field effects. Therefore, methods are discussed to ensure a consistent quality of the calibration considering the near-field influences from the ACTs. Exemplary measurements deploying an antenna array operating at 78.5 GHz demonstrate that this calibration measurement setup employing three ACTs placed in the near-field of the array reduces the calibration effort by a factor of 3 compared to state-of-the-art setups. The average deviation of the antenna phase relations amounts to 4.1 degree, proving that the presented setup achieves the same calibration quality as state-of-the-art setups.INDEX TERMS calibration, direction-of-arrival (DoA) estimation, imaging radar, MIMO radar, phased arrays, radar measurements.
“…Для забезпечення надійного та ефективного використання літаків та послуг авіації взагалі, дедалі більшого значення набуває матеріально-технічне забезпечення [1][2][3]. Невід'ємним компонентом такого матеріально-технічного забезпечення є радіотехнічні системи ближньої навігації (РБСН).…”
Стаття присвячена детальному розгляду архітектури програмно-апаратної моделі системи вимірювання кутів автоматичного радіопеленгатора. В статті розкривається функціональність антен, приймальнопередавальних блоків, блоків обробки сигналу та визначення кутів. Особлива увага приділяється взаємодії програмного та апаратного забезпечення для забезпечення оптимальної продуктивності системи. Архітектура програмноапаратної моделі системи вимірювання кутів автоматичного радіопеленгатора є ключовим аспектом у розробці та ефективному функціонуванні радіотехнічної системи ближньої навігації. Ця модель визначає структуру та взаємодію програмного та апаратного забезпечення, які використовуються для точного вимірювання кутів при отриманні радіопеленгації. В статті представлено реалізацію для моделювання приймача ADF, який є частиною з аналізом з точки зору навчальних цілей. Модель охоплює: функції системи, основні етапи обробки та необхідні контрольні точки. Змодельовані системи поєднуються з персональним комп’ютером для керування різними режимами роботи і виконують необхідні обчислення для процесу навігації. Модель може бути розширена, щоб охопити нові модулі для інших навігаційних систем авіоніки.
“…Where t indicates the intra-chirp timing from 0 to the duration of the up-chirp. The slope of the frequency ramp S and chirp repetition period T C have to be known or can be estimated with sufficient accuracy [4]. Due to the modulation principle, a single modulation frequency leads to a target with a simulated range R and velocity v. Due to the undersampling of the modulation frequency by the ramp timings ξT C , a defined phase shift between ramps can be set.…”
Section: Working Principle Of Modulation-basedmentioning
confidence: 99%
“…The relation between the ramp timing deviations ∆T and resulting phase shift of s IF is nonlinear due to the exp(•) function in (4).…”
For the development of fully-autonomously driving vehicles, advanced capabilities for sensor systems are required. With modulation-based radar target simulators, complex traffic scenarios can be simulated for automotive radars at low costs. Yet the simulation principle relies on the timings of the chirp-sequence frequency modulated continous waveform. Since small timing variations can be purposely introduced on the radar's waveform e.g. for interference mitigation techniques, the assumption of ideal timings could be violated. Therefore, this paper investigates the influences of ramp timing deviations on the target simulation. A signal model for radar timing variations for modulation-based simulators is presented. Furthermore, the influence of ramp timings on the resulting signal-to-noise ratio of simulated target responses is derived and verified by measurements.
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