Javier Gismero Menoyo

CWLFM millimeter-wave radar for ISAR imaging with range coverage

CWLFM radars have become very interesting systems. Although its functioning is known long ago, some new applications have been arisen thanks to some technological improvements. These improvements allow to work in higher frequencies what gets much better operational features for this kind of systems. High frequencies facilitate to work with wider bandwidths what improves the range resolution thus, important features of the targets can be extracted in order to classify them or even to obtain radar images of them. This paper pretends to show the implementation and some results of a MMW band radar with a range coverage of a few kilometers.

Vehicle control classification and identification through ISAR imaging

The great advantages arisen in millimeter-wave frequencies have made possible the development of high range resolution radars. The capability of using high bandwidths (Gigahertzs) increases the range resolution allowing the obtaining of targets radar signatures. Through these signatures some patterns of the targets can be extracted like its size, velocity or maybe some specific features which facilitates its recognition, classification and even identification. The increase in azimuth dimension obtained, like it is explained in this paper, thanks to Doppler processing, allows to get better estimations of the targets characteristics

Digital monopulse receivers for phase modulated signals

The great success achieved by the monopulse technique in the last years and the fact that the new technology is beginning to allow the construction of digital radar receivers, make us thinking about the digital implementation of the monopulse technique. In this paper different architectures based on amplitude and phase measurement are analyzed. Finally, the results of each architecture are given in some figures.

Real-time signal processing system for high resolution CWLFM millimeter-wave radars

An FPGA-based real-time signal processing unit has been developed to perform Doppler processing in a high resolution CWLFM (continuous wave linear frequency modulated) millimeter-wave radar demonstrator. The article focuses on the strategies followed in order to achieve the required throughput as well as on the measures taken to guarantee coherency. Doppler processing is accomplished to output Range-Doppler radar images and transfer them to a PC application for display. Two different experimental setups have been used to verify the correct operation of the processing flow. The system has been designed so as to allow for future addition of complex target detection - classification schemes.

Novel Direct Digital Synthesizer Design for OFDM Digital Receivers

This paper describes a novel design approach for the DDS (direct digital synthesizer) required to correct the frequency shift in the received signal of a digital OFDM receiver. The traditional phase accumulator has been modified to perform modulus 2N-1 accumulation. This modification provides fine frequency tuning capabilities using a very small sine/cosine look-up-table. Current systems use hundreds or thousands carriers requiring a DDS with very small frequency steps. This requires enormous amounts of memory for the sine/cosine LUT and an accumulator with many bits, limiting the maximum clock frequency. A reduction of required memory of more than 3 orders of magnitude can be achieved while an smaller phase accumulator allows for higher frequency operation. The design can deal also with systems where selectable carrier spacing is used such as DAB (digital audio broadcasting), with a minimal memory resource count increase. The design focuses on FPGA implementation although it may be applied also in an ASIC to achieve lower power and area reduction

Coherent Signal Processing for Traffic Flow Measuring Radar Sensor

This paper presents a technological demonstrator with traffic applications, which carries out three typical intelligent transportation system (ITS) tasks: traffic flow measurement, speed estimation, and vehicles classification. The proposed system is a frequency-modulated continuous wave radar working at 24 GHz, with side-looking installation. Two signal-processing modes, 1-D and 2-D, are introduced as detection scheme. Unlike other existing commercial systems, this demonstrator makes use of phase information from target echoes in order to perform clutter cancellation and target speed measurement. To this end, two different speed-estimating methods are proposed and compared by means of experimental results obtained from a complex scenario.

X-band ubiquitous radar system: First experimental results

This paper presents the first experimental results of an ubiquitous frequency modulated continuous wave (FMCW) radar system demonstrator, working in the 8.75 GHz (X band). This system, which main application is in the area of surface surveillance radars, has been developed within the framework of the project numbered as TEC2014-53815-R (RAD-DAR), and is currently under its field-testing phase. This article presents the demonstrator and describes its main blocks. Subsequently, it focuses on signal acquisition and digitization, to later explain the offline coherent signal processing carried out with the captured data. After this, the document introduces the chosen scenario for the first field tests, and shows the first results of the offline processing, illustrated with Range-Doppler matrices and detection figures. Finally, the paper introduces future work lines, including the development of a radar data processor taking advantage of the achieved strong range-speed association.

Design of radio frequency subsystems of a ubiquitous radar in X band

The purpose of this paper is to present the design of the radiofrequency subsystems of a ubiquitous radar in X band. This document is focused on the design of the antennas and the receiver. Ubiquitous radars are novel systems that illuminate a huge coverage with a transmitting antenna while receiving echoes from targets by a group of antennas pointing to the same area. The main characteristics of the receiving antennas are summarized as well as their design and measurements of radiation patterns. In the last part of the paper, the block diagram of each receiver is shown and measurements are compared with simulations.

Radar de alta resolución en distancia onda continua y modulación lineal en frecuencia para la obtención de imágenes ISAR sin compensación de movimiento

Este articulo describe la implementacion de una metodologia para la reconstruccion de estructuras anatomicas craneofaciales conformadas por tejidos duros y blandos a partir de imagenes biomedicas de modo que puedan ser utilizadas en aplicaciones que involucren el metodo de los elementos finitos en el area de la bioingenieria. Se logro reconstruir estructuras como mandibula, hueso temporal y algunas piezas dentales de manera satisfactoria, conservando las caracteristicas anatomicas reales de cada estructura y obteniendo un solido conformado por superficies que permiten hacer simulaciones biomecanicas por medio del metodo de los elementos finitos, con posibles aplicaciones en cirugia maxilofacial y ortodoncia.