579 research outputs found
Challenges and Opportunities of Doing Fieldwork as a Woman on Women in Guinea
No full textThe researcher with his or her multiple identities, his or her background, and habits forms part of the experience in the field and therefore influences data generation. In this chapter, Ammann reflects on how her identity shaped her field research on the women-state nexus in a Muslim West African city. She analyses how she has dealt with gender-related difficulties and opportunities she came across during fieldwork, especially how she adapted her ethnographic approach because accessibility to women proved to be a major challenge. In the conclusion, Ammann argues that flexibility and adaptation are key for ethnographic research. She pleads for more contributions in which not only female but also male researchers reflect on how their gendered presence influences their research settings
Irenicum Numae Pompilii, cum Hippocrate : quo veterum Medicorum & Philosophorum Hypotheses in Corpus Iuris Civilis pariter, ac Canonici, hactenus trans-sumtae / a praeconceptis Opinionibus vindicantur Mediatore D.P.A. Prof. Publ. Opus ICtis pariter, atq[ue] Medicis, utile, utpote in quo quaestiones propositae ex ipsis legum textibus, & variis responsis Facultatis Medicae Lipsiensis illustrantur
No full textPattern Reconfigurable Back-to-Back Microstrip Patch Antenna
No full textA back-to- back microstrip patch antenna with a switchable pattern is proposed for WLAN applications. The patch elements, printed on FR-4 substrates with a common ground plane, are switched with a single-pole double-throw PIN diode circuit. Switching the feed selects either of two identical radiation patterns in the opposing hemispheres for spatial diversity that would benefit a distributed network
Antipodal Vivaldi Antenna for Water Pipe Sensor and Telemetry
No full textAn antipodal Vivaldi antenna operates simultaneously for telemetry and sensing when placed conformally onto PVC pipes. Good radiation efficiency is realised and the antenna impedance matching remains stable when a pipe is empty or contains water. The fidelity factor performance based on an input Ultra-Wideband Gaussian pulse is a suitable figure of merit to detect water presence. Different water levels and pipe conditions correspond to fidelity factors between 90% and 96%, which are a suitable dynamic range for sensing and the appropriate quality for pulse communications for remote monitoring
Comparison of Grid Array and Microstrip Patch Array Antennas at 28 GHz
No full textA millimeter wave Grid Array Antenna for fifth generation (5G) communications is presented. The 20 cell, nearly-rhombic, 40×40 mm2 Grid Array Antenna structure is simulated and fabricated on a Rogers RT/Duroid 5880 substrate with thickness of 0.25 mm. The grid array has |S11
Footwear and Wrist Communication Links using 2.4 GHz and UWB Antennas
No full textIt is reported that wearable electronic devices are to be used extensively in the next generation of sensors for sports and health monitoring. The information obtained from sensors on the human body depends on the biological parameters, the measurement rate and the number of sensors. The choice of the wireless protocol depends on the required data rates and on system configurations. The communication link quality is achieved with narrowband technologies such as Bluetooth or Zigbee, provided that the number of sensors is small and data rates are low. However, real-time measurements using wideband channels may also be necessary. This paper reports narrowband link performance at 2.45 GHz for comparison with two UWB channels centered at 3.95 GHz and 7.25 GHz. A monopole antenna covering 2.45 GHz and UWB is optimized for an on-body communication link between the footwear and the wrist. The cumulative distribution function of several path loss measurements is reported and compared for a subject standing and walking. Results show that the larger bandwidth in the UWB channel reduces fading and stabilizes the channel predictability
Design Method for Wideband Circularly Polarized Slot Antennas
No full textA compact ultrawideband (UWB) circularly polarized (CP) slot antenna is proposed with a methodology for automated reoptimization for packaging with proprietary devices. The slot structure employs a dual-feed with an integrated compact UWB phase shifter. The design process involves an advanced optimization algorithm and demonstrates the use of spline curves for generation of CP signals. These allow easy optimization, while preserving phase coherency across a wideband. The prototyped antennahas a CP bandwidth of 54% (from 3.2 to 6.1 GHz)
Integration of Antenna Array with Multicrystalline Silicon Solar Cell
No full textThe integration of a low-profile antenna array with a multicrystalline silicon solar cell capable of powering a low-power wireless sensor at 2.45 GHz is reported. Lattice bus bars on the cell are exploited to minimize antenna shadows from low-profile antennas and transmission lines for a higher output power. The dual inverted-F array improves gain, and beam switching enables the array to sweep a wider coverage angle with larger beamwidths compared to other solar integrated antennas
Insole Antenna for On-Body Telemetry
No full textA 433 MHz antenna is proposed for integration with the insole of footwear for a body area network. The folded dipole design with an asymmetric groundplane radiates from its edges and considers the close proximity of the human foot and ground surfaces. It functions for different ground conductivity conditions and an on-body communication link with an Inverted F Antenna in the upper body area was evaluated on a static and dynamic human subject. The antenna solution was compliant with Specific Absorption Rate requirements, remains matched and links with upper-body nodes regardless of the body posture and node location
Footwear Antennas for Body Area Telemetry
No full textAntennas designed to link footwear sensors within body centric networks are introduced with two small UWB antennas, one directional and another quasi-omnidirectional. The radiating characteristics are evaluated for three positions on a sample sports shoe using a detailed simulation model and measurements with a homogenous foot phantom. Antenna performance is assessed for resilience to close proximity loading by the footwear materials and the phantom foot
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