Switched-Beam Antenna for WSN Nodes Enabling Hardware-driven Power Saving

Abstract

Abstract-Energy saving is one of the most important issues in Wireless Sensor Network (WSN) context. Since the communication task is the most power-consuming operation, it is quite important to achieve an energy efficient communication in order to increase the lifetime of the devices through an intelligent use of the power transmission. In this context, the integration of WSN nodes with switched-beam antennas is becoming more and more appealing due to the possibility to extend sensor node lifetime by optimizing the transmitted power.In this work a switched-beam antenna for WSNs nodes in the ISM band (2.4-2.4835 GHz) is proposed. The radiating structure consists of four identical antennas, composed of an array of two L-shaped quarter-wavelength slot antenna elements arranged in a compact and symmetrical planar structure. Thanks to a properly designed switching circuit which controls the feeding of the antenna elements, one among eight possible different radiation patterns in the azimuth plane can be selected on the basis of specific needs. Simulations and experimental results, referred to a prototype realized on a FR-4 substrate, demonstrate the appropriateness of the proposed switched-beam antenna system as hardware element enabling new power saving strategies in WSN contexts.

Wireless Sensor Network Security Enhancement Using Directional Antennas: State of the Art and Research Challenges

“…The first one employs a radiation structure made of eight microstrip antennas using rectangular two-element patch antenna arrays and a vertical half-wavelength dipole antenna [ 12 ]. The second prototype [ 35 , 36 ] uses a group of four identical antennas containing two quarter-wavelength l -shaped slot antenna elements which are disposed in a symmetrical planar structure of 10 × 10 cm 2 .…”

Dual-Beam Steerable TMAs Combining AM and PM Switched Time-Modulation

“…Furthermore, if the nodes are endowed with smart-antenna extra functionalities such as beam steering, direction finding, secure signal transmissions, etc., the antenna feeding network will need to be equipped with variable phase shifters (VPSs), which will substantially increase the costs and radiation power losses. In this regard, the benefits of using directional antennas built with switched beamforming networks (BFNs) rather than VPSs have been investigated [4,5] but in these approaches the utility of the switches consists in shifting between a set of possible positions for different radiation patterns.…”