Programa del congreso

Microwave and microfluidic techniques may enable wireless monitoring and interaction with bio-particles, yet still is a largely uncharted territory. Fortunately, the requirements of microfluidics and microwave techniques converge to the need of system miniaturization for reaching the sensitivity levels required. Accordingly, in this work, it is presented the design and optimization of a measurement setup for the system-level characterization of different designs of bio-particle-sensing coplanar-electrodes on a microfluidic-platform.

The design of the signal-chain of the measurement setup is optimized for a RF Phase-Sensitive Homodyne Receiver. In addition, the signal-integrity is achieved with a microwave-shielded-chamber, protecting from electromagnetic interference the coplanar electrodes on a microfluidic platform. As well, experimental validation of the system-level performance of the measurement setup are provided, for different coplanar-electrodes designs.

A proposal for the stable radiofrequency (RF)

reference dissemination employing fiber optics and photonic

components is analysed and its performance for fiber-distributed

antenna arrays numerically assessed. The key concept is passive

phase conjugation of a round-trip signal, achieved by smart

biasing of the conventional push-pull Mach-Zehnder modulators

(MZM) used for optical upconversion. A dual-parallel MZM

(DP-MZM) stage is proposed for the wavelength-shifting ( -

shifting) of the reinjected optical signal to avoid the deleterious

effect of fiber Rayleigh Backscattering (RBS). We report on our

preliminar results on assessment of the impact of the parameters

of the system through numerical simulations.

abstract:

The penetration capabilities of morphologic microwave imaging for medical applications, especially for human body imaging (brain, breast, etc.), have been broadly studied, yet showing not quite conclusive results. Morphological imaging aims to reconstruct the internal parts of the body by means of determining their complex permittivities. However, the large differences in permittivity generate a low contrast which translates into poor imaging accuracy.

In this paper, we present a novel technique to monitor instead the functional activity of the human body, which targets the detection of specific responses, shaped as electrical signals, of the functional activity. This technique has two main advantages: the contrast is increased with respect to classical microwave imaging as it monitors electrical responses, and it provides access to the functional activity instead of just mapping the morphology. Abnormal brain activity, in the shape of electrical pulses, are present in several medical conditions, as it is the case of patients suffering from Parkinson’s disease. The proposed technique may contribute to improve early stage detection and treatment of these conditions. A first approach to the modulation-based functional monitoring technique, reproducing electrical activity by means of a microwave bio-tag is here presented. UWB ridge horn antennas are employed for focusing and to collect the low functional signals using modulated scattering technique.

Agriculture 4.0 is going to represent a massive deployment of sensors, so efficient planning of radiocommunication systems in this type of environment will be necessary. In this work, the measured path loss in a LoS situation, with the transmitter and receiver heights below the trees height, at a citrus plantation in the 1800MHz, 2100MHz, 3.5GHz and 28GHz frequency bands using the FI (Floating Intercept) and the CI (Close-In reference) models has been analyzed. It has been observed that from 3.5GHz, the slope of the FI model also represents the propagation exponent (PLE). Furthermore, a guiding effect (PLE less than 2) has been observed in the 1800MHz and 2100MHz bands, not in the 3.5GHz and 28GHz bands, in which the PLE is practically equal to 2 (free space). Finally, the analysis of the polarization reveals that the standard deviation of the measured values with respect to the values obtained from the models is greater for horizontal than vertical polarization in the 1800MHz and 2100MHz frequency bands.

The trend in vehicles is to integrate a wide number of antennae and sensors operating in a variety of frequencies to sense around and for communications. The integration of these antennae and sensors in the vehicle platform is complex because of interactions of antenna radiation pattern with the vehicle structure and with other antennae/sensors. In consequence, it is required to study the radiation pattern of each antenna, or alternatively the induced currents on the vehicular surface to optimize multiple antenna integration. The novel concept of differential imaging is an alternative method to obtain the surface current distribution without introducing any perturbing probe. The aim of this communication is to contribute, by means of full wave electromagnetic simulation, to develop and confirm the approximations assumed in the differential imaging, providing an ad-ditional verification of the concept. Simulation environment and parameters were selected to replicate the same conditions as the real measurement of previous studies. The simulations have been performed using the well-proven ANSYS HFSS simulation software. The results confirm that the approximations are valid, and the differential currents are representative of the induced surface currents generated by a monopole at the top of a vehicle and the near electric field distribution.