A simple, compact, and novel UWB antenna with dual band-notch characteristics is proposed in this letter. The central frequencies of the dual notched bands can be adjusted with ease by proper selection the lengths of the parasitic strip and the tuning stub and there is a litter influence to a band-notched characteristic when another is changed. The experimental results exhibit that the fabricated antenna covers over an ultra-wideband band for VSWR Ͻ 2, while avoiding EM interference with the WIMAX band (3.3-3.7 GHz) and WLAN band (5.15-5.825 GHz). Moreover, the proposed antenna has good radiation characteristics on the operating frequency.
ACKNOWLEDGMENTThe authors thank Professor Yin for the guidance of antenna measurement, and colleagues for the effort of simulation and measurement. This work was supported by the National Key Laboratory of Antenna and Microwave Technology.
Observing microclimate changes is one of the most popular applications of wireless sensor networks. However, some target environments are often too dangerous or inaccessible to humans or large robots and there are many challenges for deploying and maintaining wireless sensor networks in those unfriendly environments. This paper presents a mobile sensor network system for solving this problem. The system architecture, the mobile node design, the basic behaviors and advanced network capabilities have been investigated respectively. A wheel-based robotic node architecture is proposed here that can add controlled mobility to wireless sensor networks. A testbed including some prototype nodes has also been created for validating the basic functions of the proposed mobile sensor network system. Motion performance tests have been done to get the positioning errors and power consumption model of the mobile nodes. Results of the autonomous deployment experiment show that the mobile nodes can be distributed evenly into the previously unknown environments. It provides powerful support for network deployment and maintenance and can ensure that the sensor network will work properly in unfriendly environments.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.