Raúl Guzmán-Quirós

A Fabry–Pérot Antenna With Two-Dimensional Electronic Beam Scanning

A novel fixed-frequency electronically steerable Fabry-Pérot Antenna (FPA) with electronic two-dimensional (2-D) (azimuth and elevation) steering capability is presented. The configuration is based on a centrally fed Fabry-Pérot cavity (FPC) loaded with a tunable high impedance surface (HIS). Varactor diodes are used to electronically tune the HIS reflection coefficient, forming four azimuthal sectors that are independently controlled by four control signals, respectively. It is demonstrated that this simple configuration generates a pencil beam that can be pointed to eight discrete azimuthal directions, whereas continuous elevation scanning is also attained simultaneously for each azimuthal direction by controlling the leaky-wave propagation constant. The theory, simulation analysis, and experimental results obtained from a prototype operating at 5.5 GHz are presented to validate the antenna design.

Integration of Directional Antennas in an RSS Fingerprinting-Based Indoor Localization System.

In this paper, the integration of directional antennas in a room-level received signal strength (RSS) fingerprinting-based indoor localization system (ILS) is studied. The sensor reader (SR), which is in charge of capturing the RSS to infer the tag position, can be attached to an omnidirectional or directional antenna. Unlike commonly-employed omnidirectional antennas, directional antennas can receive a stronger signal from the direction in which they are pointed, resulting in a different RSS distributions in space and, hence, more distinguishable fingerprints. A simulation tool and a system management software have been also developed to control the system and assist the initial antenna deployment, reducing time-consuming costs. A prototype was mounted in a real scenario, with a number of SRs with omnidirectional and directional antennas properly positioned. Different antenna configurations have been studied, evidencing a promising capability of directional antennas to enhance the performance of RSS fingerprinting-based ILS, reducing the number of required SRs and also increasing the localization success.

Design of Ku-band wireless power transfer system to empower light drones

A wireless power transfer system is conceived to empower light drones and unmanned aerial vehicles. To satisfy the power budget of the wireless link and provide enough power to the drone, new circuits based on directive frequency-scanned leaky-wave antennas and circuits are proposed. It is shown how the proposed leaky-wave devices introduce enough gain in the receiver system, while assuring reception in a 120° field-of-view scanning range. At the same time, the suggested receiver system has low weight and cost since it is fully designed in PCB-compatible substrate integrated microwave technology. Preliminary results on this interesting system for wireless power transfer are presented in this paper.

Reducing the beam squint in scanned leaky-wave antennas using coupled SIW cavities

The systematic design of broadband, directive, scanned planar leaky-wave antennas using coupled-cavity substrate integrated waveguide technology is reported in this work. The design methodology is based on the optimization of the corresponding transverse resonance phase equation, so that a constant scanning angle condition is satisfied for a wide frequency band. This design process is validated with full-wave simulations of a 4th order-cavity optimized design. A 3dB scanned pattern bandwidth of 1.5GHz with 10dBi directivity at a central frequency of 15GHz (10% fractional bandwidth), is reported for 30° elevation scanning angle. This is a much higher bandwidth than conventional 1.7% bandwidth associated to the same type of antenna with a single SIW cavity.