Compact left-handed dual-band filters based on shundted stub resonators

In this paper, super-compact microstrip dual-band resonator is presented, designed using the superposition of two simple left-handed (LH) resonators with single shunt stub. The proposed resonator exhibits spurious response in wide frequency range and therefore allows construction of dual-band filters using the superposition principle. The equivalent circuit model of the proposed resonator is crated and the influence of different geometrical parameters to the performances of the resonator are analyzed in details. As an examples, two dual-band filters that operate simultaneously at the WiMAX frequency bands are designed.

Inferring and Removing a Spurious Response in the Optical Backscattering Signal from an Autonomous Profiling Float

Development of autonomous profiling floats, allowing for long-term continuous measurement of bio-optical variables, promises to significantly increase our knowledge of the variability of the particulate optical backscattering coefficient bbp in marine environments. However, because autonomous floats are designed for unattended data collection and only rarely are recovered for analysis of the condition of the sensors in situ, the quality-control analysis of float data streams is of paramount importance in both a particular dataset and the larger understanding of the response of sensors over the lifetime of the floats. Anomalous data from a backscattering sensor (MCOMS) mounted on autonomous profiling floats are reported here. The observed sensor behavior, which presents itself as significant differences in the values observed at the parking depth between profiles, caused by a steady increase in the signal during the profiling time, is neither common to all sensors nor can it be a function of changes in the particle population. A simple quality-control procedure that is able to detect this spurious sensor response is proposed. Further characterization of this effect will require laboratory experimentation under controlled conditions of temperature and pressure.