Optimized differential TCDA (D-TCDA) with novel differential feed structure

Modern phased arrays require large instantaneous bandwidths, wide fields of view, and low profiles to conduct multiple functions. Many of these phased arrays rely on emerging high speed ADCs and advanced balanced transceivers. The benefits of balanced front-ends include improved linearity, dynamic range, isolation, and noise resilience. The application of a differential phased array in such a system removes extraneous losses caused by baluns, though the issue of feed-borne E-plane scan resonances must be considered. We address the E-plane scan resonance issue through an improved Balanced Wideband Impedance Transformer (BWIT) feed for the ultra-wideband (UWB) Tightly Coupled Dipole Array (TCDA). This BWIT feed has already demonstrated mitigated common-modes over a 3:1 bandwidth ratio while scanning to low angles. Here, our differential TCDA (D-TCDA) is developed for the L-C band (viz. 1.0 GHz to 6.1 GHz) with emphasis on resonance-free wide-angle scanning. Rigorous EM model and circuit analysis is included to verify the BWIT performance. Under a VSWR \u3c 3 definition, the improved array achieves a 6:1 impedance bandwidth ratio (BWR) with resonance-free scanning in all planes. An exception is the H-plane scanning at 60◦ where the VSWR \u3c 4. Array simulations are verified with measurements for an 8×8 single-polarized prototype

Low-Cost S-Band Reconfigurable Monopole/Patch Antenna for CubeSats

The development of reconfigurable antennas compatible with a CubeSat form factor can aid several space missions. Often, satellite missions require multiple wireless links with the same radio, but the design of such antennas is challenging due to the mechanical constraints and the limited power aboard a CubeSat. In this article, we present a unique reconfigurable antenna concept enabled by adhesive polyimide tapes. The presented antenna can switch from a conventional patch to a monopole-like antenna with minimal actuation complexity. This reconfiguration provides choices for polarization, pattern, and gain without use of active components for size, cost and power consumption reductions. The frequency of operation is S-band (2.4 GHz), and the antenna achieves S_{11} \u3c -10 dB for both reconfiguration states. Measurements compare well with simulations in both states

The Core Value Compass: visually evaluating the goodness of brands that do good

yesBrands that do good for the society as well as for themselves are motivated by the core values they espouse, which necessitates a better understanding of what qualities a true core value must possess. The inherent tension within brands that do good, between commercial interests to increase competitiveness, and societal interests that are closely linked to the brand’s authenticity, has largely been overlooked. Hence, we develop and demonstrate a relatively easy-to-apply visual tool for evaluating core values based on a set of ‘goodness’ criteria derived from extant theory. The Core Value Compass adopts a paradox-based, evolutionary perspective by incorporating the inherent tensions within true core values, and classifying them according to their temporal orientation. Thus, we contribute towards a better understanding of underlying tensions of core values and provide a practical tool that paves the way for improved, and indeed ethical, corporate branding strategies. Furthermore, we demonstrate the Compass’ application using the case of a public sector brand, which is a quintessential brand that does good. Therefore, we also contribute to the nascent theoretical discourse on public sector branding. This paper therefore adds to the notable attempts to bridge the gap between theory and practice in core values-based corporate branding

Electromagnetic Characterizations of Mesh Deployable Ka Band Reflector Antennas for Emerging CubeSats

CubeSats are a miniaturized class of satellites that are launched as secondary payloads, offering the possibility of carrying out advanced space missions at affordable costs. Mechanical constraints and limited power onboard have limited current antenna implementations to low-gain, low data rate, and near-omnidirectional patterns. Integrating high gain aperture antennas with CubeSats can offer innumerable possibilities for advanced space missions. However, packaging large apertures into the small CubeSat form factor presents a formidable challenge to the scientific community. This thesis investigates the potential of integrating a 1m offset mesh deployable reflector antenna system with a 2.5U (10cmx10cmx25cm) CubeSat chassis for Ka band remote sensing or communications. Packaging such a large aperture into the small 2.5U volume necessitates a completely customized reflector design for our application. A detailed study of deployable umbrella mesh reflectors, RF analysis of various reflector antenna configurations and feed design methodologies are included in this work. These particular studies not only demonstrate the feasibility of the next high-gain antenna; they mark a major milestone (a 1m antenna size) for CubeSats, which is among the largest to be utilized for Ka band

Novel High Gain Antennas for Emerging CubeSats: Characterization of Deployable Mesh Reflectors and Low-Profile, Metal-Only Stepped Reflectors

The advent of VLSI and microelectronics has made it possible to reduce the size of electronic devices by several orders of magnitude while increasing their functional capabilities and reducing production costs. This massive scaling has enabled the development of satellites that can be as small as a cube of volume 10 cm x 10 cm x 10 cm. Such satellites, called ‘CubeSats’, have revolutionized the satellite industry today. This reduced volume makes launching CubeSats economically affordable, fostering the participation of small scale establishments and universities in space programs. Owing to their small size, it is now possible to conceive launching of multiple instances of the same CubeSat for advanced missions, which was not economically viable with conventional satellites. Even though numerous CubeSats have been launched, most of the current CubeSat missions operate at low data rates and low spatial resolution. One of the major reasons for this is the absence of compact high gain antennas that can integrate with the small CubeSat form factor while providing the required data rates for deep space missions or spatial resolution for remote sensing. This work addresses this very challenge by developing tools that can aid the integration of high gain antennas with the small CubeSat form factor. In particular, we include the following: (a) an in-depth understanding of umbrella reflector antennas with an emphasis on lower number of ribs to aid stowage, (b) analysis of complex knit mesh surfaces to understand the tradeoff between mesh density and RF transmission loss, (c) innovative feed designs that are optimized for efficient illumination of reflector antennas and minimum volume, (d) characterization of chassis interaction with the antenna system, and (e) development of a metal-only, low-profile, stepped parabolic reflector that can be 3D printed and readily integrated with the CubeSat chassis, simplifying deployment. As a part of this dissertation, we describe the development of one of the largest apertures at Ka-band: a 1m mesh-deployable offset reflector that can be stowed in a volume of 10 cm x 10 cm x 30 cm. The success of this endeavor marks a major milestone in the field of CubeSats, which allows advanced space missions at lower costs to become a reality

Novel High Gain Antennas for Emerging CubeSats: Characterization of Deployable Mesh Reflectors and Low-Profile, Metal-Only Stepped Reflectors

The advent of VLSI and microelectronics has made it possible to reduce the size of electronic devices by several orders of magnitude while increasing their functional capabilities and reducing production costs. This massive scaling has enabled the development of satellites that can be as small as a cube of volume 10 cm x 10 cm x 10 cm. Such satellites, called ‘CubeSats’, have revolutionized the satellite industry today. This reduced volume makes launching CubeSats economically affordable, fostering the participation of small scale establishments and universities in space programs. Owing to their small size, it is now possible to conceive launching of multiple instances of the same CubeSat for advanced missions, which was not economically viable with conventional satellites. Even though numerous CubeSats have been launched, most of the current CubeSat missions operate at low data rates and low spatial resolution. One of the major reasons for this is the absence of compact high gain antennas that can integrate with the small CubeSat form factor while providing the required data rates for deep space missions or spatial resolution for remote sensing. This work addresses this very challenge by developing tools that can aid the integration of high gain antennas with the small CubeSat form factor. In particular, we include the following: (a) an in-depth understanding of umbrella reflector antennas with an emphasis on lower number of ribs to aid stowage, (b) analysis of complex knit mesh surfaces to understand the tradeoff between mesh density and RF transmission loss, (c) innovative feed designs that are optimized for efficient illumination of reflector antennas and minimum volume, (d) characterization of chassis interaction with the antenna system, and (e) development of a metal-only, low-profile, stepped parabolic reflector that can be 3D printed and readily integrated with the CubeSat chassis, simplifying deployment. As a part of this dissertation, we describe the development of one of the largest apertures at Ka-band: a 1m mesh-deployable offset reflector that can be stowed in a volume of 10 cm x 10 cm x 30 cm. The success of this endeavor marks a major milestone in the field of CubeSats, which allows advanced space missions at lower costs to become a reality

Electromagnetic Characterizations of Mesh Deployable Ka Band Reflector Antennas for Emerging CubeSats

CubeSats are a miniaturized class of satellites that are launched as secondary payloads, offering the possibility of carrying out advanced space missions at affordable costs. Mechanical constraints and limited power onboard have limited current antenna implementations to low-gain, low data rate, and near-omnidirectional patterns. Integrating high gain aperture antennas with CubeSats can offer innumerable possibilities for advanced space missions. However, packaging large apertures into the small CubeSat form factor presents a formidable challenge to the scientific community. This thesis investigates the potential of integrating a 1m offset mesh deployable reflector antenna system with a 2.5U (10cmx10cmx25cm) CubeSat chassis for Ka band remote sensing or communications. Packaging such a large aperture into the small 2.5U volume necessitates a completely customized reflector design for our application. A detailed study of deployable umbrella mesh reflectors, RF analysis of various reflector antenna configurations and feed design methodologies are included in this work. These particular studies not only demonstrate the feasibility of the next high-gain antenna; they mark a major milestone (a 1m antenna size) for CubeSats, which is among the largest to be utilized for Ka band

The analgesic activity of novel synthesized tetrapeptides: overview

The tetrapeptide class of biased analgesics from an Australian fungus targets the -opioid receptor. The current study sought to investigate the analgesic and anti-inflammatory effects of Tyr-MIF-1 mimetics in rats suffering from acute pain. We report the synthesis of two new compounds which are hybrid molecules between the substituted pyrrole (Pyr) and analogues of Tyr MIF-1 peptide. The in vitro opioid activity of the analogs was tested in the guinea pig ileum (GPI) and naloxone-induced pain model. The study examined the effect of an analog to an N-terminal nociceptin fragment on the behavior of albino rats. We have also elucidated a novel G protein-biased agonist, Phe-Phe-Asp]NH2, for the management of moderate to severe acute pain following abdominoplasty. The pharmacophore based on Phe, NH2, was synthesised and characterized by solid phase chemistry and high performance liquid chromatography/mass spectrometry (HPLC/MS). The results show that a series of hybrid molecules with a unique stereochemical arrangement of hydrophobic amino acids, bilaids A-C, were synthesized. The effects of a new molecule, an analog of N-Terminal Nociceptinal Fragment (PK20M), on motor and exploratory activity of mature rats and in 42-day pups and 21-day rat pups were evaluated. The antinociceptive and antipyretic activities of the original molecule were evaluated in a model of post-incisional pain in rats at doses lower than 1g/kg. The present study reporting the overview of analgesic activity of some novel synthesized tetrapeptides fragments shows satisfaction effects comparing with morphine, aspirin, naloxone, etc