This Letter proposes the use of a modal pattern stability factor (MPSF) parameter to quantify the pattern stability associated to characteristic modes (CM). The proposed parameter can be used as a ...figure of merit for CM associated to arbitrary-shaped structures, aiding the antenna design process. This parameter can be used (together with other modal parameters) to optimise the geometry of a radiating element in order to improve the radiation pattern stability in a desired range of frequencies. Two examples are presented for analysis. First, MPSF for the CM of three ring antennas with different width are analysed, showing how pattern stability of CM depend on this geometrical parameter. Secondly, three metallic plates with different shapes are analysed in terms of MPSF, in order to assess the stability of the CM for each geometry.
An ultra-wideband (UWB) planar monopole antenna with a tunable band-notched response is proposed. Tuning of the rejected frequency is realised by loading an embedded resonant slot with a varactor. ...Simulations and measurements are presented for the proposed antenna, both in frequency and time domain.
Vertebrates are recognized as sentient beings. Consequently, urgent priority is now being given to understanding the needs and maximizing the welfare of animals under human care. The general health ...of animals is most commonly determined by physiological indices e.g., blood sampling, but may also be assessed by documenting behavior. Physiological health assessments, although powerful, may be stressful for animals, time-consuming and costly, while assessments of behavior can also be time-consuming, subject to bias and suffer from a poorly defined link between behavior and health. However, behavior is recognized as having the potential to code for stress and well-being and could, therefore, be used as an indicator of health, particularly if the process of quantifying behavior could be objective, formalized and streamlined to be time efficient. This study used Daily Diaries (DDs) (motion-sensitive tags containing tri-axial accelerometers and magnetometers), to examine aspects of the behavior of bycaught loggerhead turtles, Caretta caretta in various states of health. Although sample size limited statistical analysis, significant behavioral differences (in terms of activity level and turn rate) were found between “healthy” turtles and those with external injuries to the flippers and carapace. Furthermore, data visualization (spherical plots) clearly showed atypical orientation behavior in individuals suffering gas emboli and intestinal gas, without complex data analysis. Consequently, we propose that the use of motion-sensitive tags could aid diagnosis and inform follow-up treatment, thus facilitating the rehabilitation process. This is particularly relevant given the numerous rehabilitation programs for bycatch sea turtles in operation. In time, tag-derived behavioral biomarkers, TDBBs for health could be established for other species with more complex behavioral repertoires such as cetaceans and pinnipeds which also require rehabilitation and release. Furthermore, motion-sensitive data from animals under human care and wild conspecifics could be compared in order to define a set of objective behavioral states (including activity levels) for numerous species housed in zoos and aquaria and/or wild species to help maximize their welfare.
Design of VHF/UHF Antennas for CubeSat using Characteristic Modes LLanga-Vargas, A.; Penafiel-Ojeda, C.; Cabedo-Fabres, M. ...
2022 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting (AP-S/URSI),
2022-July-10
Conference Proceeding
This paper presents the application of the Characteristic Mode Theory for the design of CubeSat antennas in the VHF and UHF bands. It is shown that the addition of radial monopoles allows to obtain ...arbitrary directional patterns and polarizations, combining the degenerate modes appearing at the same frequency.
This paper presents a very low-profile on-ground chip antenna. The antenna is designed using LTCC technology. The total volume of the antenna is 0.067λ × 0.048λ × 0.019λ, and the antenna does not ...require a clearance area on the ground plane. The antenna is proposed for 2.4 GHz IoT applications for extreme size-limited devices. A study in terms of matching and total efficiency is performance in two different size ground planes with the antenna installed in different positions. Results show a total efficiency difference up to 4 dB and a high frequency stability.
An ultra-wideband planar monopole antenna with a tunable band-notched response is proposed. Tuning of the rejected frequency is realised by loading an embedded resonant slot with a varactor. The ...simulations and measurements are presented for the proposed antenna, both in frequency and time domain.
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