Mayazzurra Ruggiano

Bio: Mayazzurra Ruggiano is an academic researcher from Thales (Netherlands). The author has contributed to research in topics: Radar & Signal processing. The author has an hindex of 3, co-authored 4 publications receiving 35 citations.

A method for filtering a radar signal after it has been reflected by a target

Abstract: A signal y is received by a radar, the signal y being the reflection of a signal s emitted by the radar, the signal s having been reflected by a target. A filter w is estimated and applied to the signal y, in which the filter w compensates for an unwanted and beforehand unknown distortion d in the emitted signal s.

Improvement of target resolution in azimuth by LMMSE technique

Abstract: Azimuth target separation is of crucial importance in many applications of radar. The azimuth resolution is determined by the antenna beamwidth. However, in practice, standard signal processing techniques require the distance between targets to be more than one resolution cell. This can prove inadequate for several relevant applications. In this paper the problem of improving the azimuth resolution for rotating surveillance radar is addressed. A data model for the case is described and a novel application of the linear minimum mean square error (LMMSE) processing technique is evaluated. The antenna pattern used is obtained from real measurements and the received signal is synthesized to produce target profiles with spacing smaller and larger than the resolution cell. Results show the capabilities of this technique of separating targets in azimuth spaced closer or further than one azimuth resolution cell. The processing scheme shows a large improvement in the resolution capability with respect to standard techniques.

Robust improvement of unmasking capabilities of iterative LMMSE filtering

Abstract: A general aim in radar processing is to allow for target separation. Several advanced techniques have been developed to fulfill this aim. Nevertheless they pose a heavy constraint on the signal reference known at the receiver, and degrade their performance when this reference is incorrect. This paper addresses the problems that rise when there is a discrepancy between the echoing signal and the signal reference used in the processing. A technique is then developed to counteract the degradation of the performance.

Characterization of GaN HEMT Low-Frequency Dispersion Through a Multiharmonic Measurement System

Abstract: In this paper, the experimental characterization of low-frequency dispersion (i.e., long-term memory effects) affecting microwave GaN HEMTs is carried out by adopting a new nonlinear measurement system, which is based on low-frequency multiharmonic signal sources. The proposed setup, which has been fully automated by a control software procedure, enables given source/load device terminations at fundamental and harmonic frequencies to be synthesized. Different experimental results are provided to characterize well-known effects related to low-frequency dispersion (e.g., knee walkout and drain current collapse) and to demonstrate the validity of assumptions commonly adopted for electron device modeling.

Imaging for a Forward Scanning Automotive Synthetic Aperture Radar

Abstract: In this paper, we propose a forward scanning synthetic aperture radar methodology for a forward-looking automotive (low-terahertz) radar, which combines scene scanning with synthetic aperture processing, resulting in enhanced angular resolution and improved imaging. We propose two algorithms, first, a modified back-projection (BP) algorithm and, second, a compressed sensing-based BP algorithm. We suggest techniques to reduce computational complexity of the proposed algorithms. Results of simulation and real-data experiments corroborate the validity of our proposed methodology and algorithms.

Going Nonlinear

Abstract: Since the advent of the nonlinear vector network analyzer (NVNA), microwave engineers have become familiar with new terminology regarding nonlinear network parameters such as "X-parameters" (registered trademark of Agilent Technologies), "S-functions", and "waveform engineering/the Cardiff model", as well as new types of equipment used to perform nonlinear characterizations. These nonlinear network parameter approaches have been developed by Root and Verspecht, Verbeyst and Vanden Bossche, and Tasker. Equipment is now commercially avail able to measure these parameters. To date, X-parameters and S-functions have been predominately used to describe amplifiers in system level simulations. Wave form engineering with the Cardiff model has focused on transistor-level amplifier design. Understanding these behavioral modeling approaches allows their application as an effective and time-saving tool for nonlinear power amplifier design. This article examines the X-parameters and S-functions in an effort to provide a working knowledge that will also apply to understanding the other aforementioned approaches.

Novel Architecture for LTE World-Phones

Abstract: The 4th Generation of mobile communications (4G) came with new challenges on the antenna bandwidth and on the front-end architecture of mobile phones. This letter proposes a novel architecture overcoming these challenges. It includes narrowband tunable antennas, co-designed with a tunable front rnd (FE). Simulations and measurements demonstrate the concept for low and high bands of the LTE frequency spectrum.

Note: The intermodulation lockin analyzer.

Abstract: Nonlinear systems can be probed by driving them with two or more pure tones while measuring the intermodulation products of the drive tones in the response. We describe a digital lockin analyzer which is designed explicitly for this purpose. The analyzer is implemented on a field-programmable gate array, providing speed in analysis, real-time feedback, and stability in operation. The use of the analyzer is demonstrated for intermodulation atomic force microscopy. A generalization of the intermodulation spectral technique to arbitrary drive waveforms is discussed.