Programa del congreso

This paper presents the analysis of a ubiquitous frequency modulated continuous wave (FMCW) radar system demonstrator, working at 8.75 GHz (X band). The main application of the system is the surface surveillance. This article presents the demonstrator and describes its main blocks. The document introduces the chosen scenario for field tests, and shows results of the offline processing illustrated with Range-Doppler matrix. This paper shows the active calibration procedure used to reduce unbalances between channels. The radar is a high range resolution system that performs the digital beamforming only on receive. To calibrate the system, an auxiliary rotating radiating source plus an electro-optical delay line are used

This paper presents preliminary results of recent HydroSoil radar continuous monitoring campaigns over agriculture fields. Future Radar Earth Observation missions with reduced revisit times will offer the capability to obtain valuable water cycle data applicable in agriculture and meteorology. Some of the phenomena involved have time scales much shorter than present satellite revisit times and for this reason are not well understood. HydroSoil measurements over barley and corn crops have provided valuable data to better understand air humidity and dew impacts on magnitude and phase of radar backscattering, which depends also on soil moisture and rain. Both barley and corn observations have shown a daily cycle magnitude ripple in the order of 1 to 3 dB caused by dew. Interferometric coherence has shown a strong dependence with plants height which can be exploited to sense the crop growth from radar observations

Current cardiopulmonary activity monitoring is based on contact devices which cannot be used in extreme cases such as premature infants, burnt victims or rescue operations. In order to overcome these limitations, the use of radar technologies emerges as an alternative. This paper aims to enhance the comprehension that non-contact technologies, in particular radar techniques, offer as a monitoring tool. For this purpose, a modified low cost commercial 122 GHz frequency-modulated continuous-wave (FMCW) radar is used to better fit the current application domain. The radar signals obtained are processed using a classic linear filtering algorithm aiming to separate the breathing from the heartbeat component while preserving signals integrity. In a standoff configuration and with different subject orientations, results show that the signal obtained with the radar can be used to extract not only the respiratory and heartbeat rates, but also the heart rate variability (HRV) sequence. Moreover, results evidence the coupling between breathing and heartbeat, also showing that the HRV sequence obtained can identify the respiratory sinus arrhythmia (RSA) effect. Finally, the radar is tested in a simultaneous multi-target scenario, demonstrating its monitoring capabilities in more complex situations. Nevertheless, there are some challenges left to use the system in a real-life monitoring environments, such as the removal of random body movements.

En este artículo se comparan una estructura de tablero de ajedrez periódica basada en rotaciones seleccionadas de un elemento CSSR (anillos resonantes divididos en forma de C) con una estructura no periódica basada en rotaciones aleatorias del elemento CSSR, ambas para reducir la RCS. En ambas estructuras se combina la diferencia de fase de 180º entre elementos a partir de las diferentes rotaciones del elemento CSSR junto con la rotación de polarización. Posteriormente, se comparan las mismas estructuras añadiendoles con un elemento absorbente RFSS Square Ring.

This paper presents a cavity-fed double-slot antenna array in SIW technology at millimeter-waves frequencies. The double slots allow better control in the designed frequency band regarding the single slots. To demonstrate this fact, a brief performance comparison between the two implementations are shown. The prototyped antenna contains 4 cavity-backed subarrays in one SIW-layer where each cavity has in its corners the double-slots therefore, we achieve a 4x4 array. To feed all the cavities, a corporate network is used. At the outputs of the feeding network, the power is coupled through rectangular apertures to the cavity-backed antennas. The manufactured antenna array experimentally provides a bandwidth from 35.4 GHz to 37 GHz. There is good agreement between simulated and measured results, with a stable measured gain about 17 dBi along the frequency band.