A twin spiral planar antenna for UWB medical radars

A planar-spiral antenna to be used in an ultrawideband (UWB) radar system for heart activity monitoring is presented. The antenna, named “twin,” is constituted by two spiral dipoles in a compact structure. The reflection coefficient at the feed point of the dipoles is lower than −8 dB over the 3–12 GHz band, while the two-dipoles coupling is about −20 dB. The radiated beam is perpendicular to the plane of the spiral, so the antenna is wearable and it may be an optimal radiator for a medical UWB radar for heart rate detection. The designed antenna has been also used to check some hypotheses about the UWB radar heart activity detection mechanism. The radiation impedance variation, caused by the thorax vibrations associated with heart activity, seems to be the most likely explanation of the UWB radar operation.

Design and Test of a 0.5 THz Dipole Antenna With Integrated Schottky Diode Detector on a High Dielectric Constant Ceramic Electromagnetic Bandgap Substrate

This paper presents the first analysis of the input impedance and radiation properties of a dipole antenna, placed on top of Fan 's three-dimensional electromagnetic bandgap (EBG) structure, (Applied Physics Letters, 1994) constructed using a high dielectric constant ceramic. The best position of the dipole on the EBG surface is determined following impedance and radiation pattern analyses. Based on this optimum configuration an integrated Schottky heterodyne detector was designed, manufactured and tested from 0.48 to 0.52 THz. The main antenna features were not degraded by the high dielectric constant substrate due to the use of the EBG approach. Measured radiation patterns are in good agreement with the predicted ones.

Antenna Simulations and Measurements of Focal Plane Array Facet Reflectors

We present a conceptual prototype model of a focal plane array unit for the STEAMR instrument, highlighting the challenges presented by the required high relative beam proximity of the instrument and focus on how edge-diffraction effects contribute to the array's performance. The analysis was carried out as a comparative process using both PO & PTD and MoM techniques. We first highlight general differences between these computational techniques, with the discussion focusing on diffractive edge effects for near-field imaging reflectors with high truncation. We then present the results of in-depth modeling analyses of the STEAMR focal plane array followed by near-field antenna measurements of a breadboard model of the array. The results of these near-field measurements agree well with both simulation techniques although MoM shows slightly higher complex beam coupling to the measurements than PO & PTD.

Efficient and Robust Host–Guest Antenna Composite for Light Harvesting

We report discovery of a new efficient and robust antenna composite for light harvesting. The organic dye hostasol red (HR) is strongly luminescent in aprotic solvents but only weakly luminescent in potassium zeolite L (ZL) at ambient conditions. We observed a dramatic increase of the luminescence quantum yield of HR–ZL composites if some or all exchangeable potassium cations of ZL are substituted by an organic imidazolium cation (IMZ+) and if the acceptor HR is embedded in the middle part of the channels, so that it is fully protected by the environment of the perylene dye tb-DXP. This led to the discovery of a highly efficient donor,acceptor-ZL antenna material where tb-DXP acts as donor and HR acts as acceptor. The material has a donor-to-acceptor (D/A) absorption ratio of more than 100:1 and a nearly quantitative FRET efficiency. Synthesis of this host–guest material is reported. We describe a successful procedure for achieving full sealing of the ZL channel entrances such that the guests cannot escape. This new material is of great interest for applications in luminescent solar concentrator (LSC) devices because the efficiency killing self-absorption is very low.

Printed Narrative: The Festival Books for Archduke Ernest of Austria from Brussels and Antwerp 1594

Workshop „The Narrative in Eastern and Western Art“, Graduate School of Letters, Kyoto, 2-5 December 2013 Abstract by Ivo Raband, University of Berne Printed Narrative: The Festival Books for Ernest of Austria from Brussels and Antwerp 1594 During the early modern period the medium of the festival book became increasingly more important as an object of ‘political narration’ throughout Europe. Focusing on Netherlandish examples from the sixteenth and seventeenth centuries, my talk will focus on the festival books printed for the Joyous Entries of Archduke Ernest of Austria (1553–1595). Ernest was appointed Governor General of the Netherlands by King Philipp II in 1593, being the first Habsburg Prince to reside in Brussels since 30 years. In Brussels and Antwerp, the Archduke was greeted with the traditional Blijde Imkomst, Joyous Entry, which dates back to the fourteenth century and was a necessity to actually become the sovereign of Brabant and Antwerp and to uphold the privileges of the cities. Decorated with ephemeral triumphal arches, stages, and tableaux vivants, both cities welcomed Ernest and, at the same time, demonstrated their civic self-assurance and negotiated their statuses. In honor of these events of civic power, the city magistrates commissioned festival books. These books combine a Latin text with a description of the events and the ephemeral structures, including circa 30 engravings and etchings. Being the only visual manifestation of the Joyous Entries, the books became important representational objects. The prints featured in festival books will be my point of departure for discussing the importance of narrative political prints and the concept of the early modern festival book as a ‘political object’. By comparing the prints from Ernest’s entries with others from the period between 1549 and 1635, I will show how the prints became as important as the event itself. Thus, I want to pose the question of whether it would have been possible to substitute a printed version of the event for the actual ceremony.

Konzessionen und Monopole in den deutschen Schutzgebieten : ein Rechtsgutachten

von Johs. Bollmann