Reconfigurable phased antenna array for extending cubesat operations to Ka-band: Design and feasibility

Started as educational tools, CubeSats have immediately encountered the favor of the scientific community, subsequently becoming viable platforms for research and commercial applications. To ensure competitive data rates, some pioneers have started to explore the usage of the Ka-band beside the conventional amateur radio frequencies. In this context, this study proposes a phased antenna array design for Ka-band downlink operations consisting of 8 78 circularly polarized subarrays of microstrip patches filling one face of a single CubeSat unit. The conceived structure is developed to support 1.5 GHz bandwidth and dual-task missions, whose feasibility is verified by proper link budgets. The dual-task operations are enabled by a low-complexity phase-only control algorithm that provides pattern reconfigurability in order to satisfy both orbiting and intersatellite missions, while remaining adherent to the cost-effective CubeSat paradigm

Design procedures for rectangular patch antennas

The work presented in this paper aims at comparing different approaches for the design of a rectangular microstrip patch antenna operating at millimeter waves. In the paper, the designed antenna is simulated using approximate formulas available from previous research, and also using the electromagnetic software CST (Computer Simulation Technology). Precisely, two optimization procedures are proposed for the same desired antenna, one using the internal CST optimizer and the other the modeFRONTIER software, which is specifically designed for solving optimization problems. All the obtained results are mutually compared, thus highlighting advantages and drawbacks of these approaches

Su di un singolare caso di ittero ostruttivo.

LA RADIOLOGIA MEDICA (TORINO

Diagnostic imaging costs before and after digitla tomosynthesis implementation in patient management after detection of suspected thoracic lesiions on chest radiography

7OBJECTIVES: To evaluate diagnostic imaging costs before and after DTS implementation in patients with suspected thoracic lesions on CXR. METHODS: Four hundred sixty-five patients (263 male, 202 female; age, 72.47 ± 11.33 years) with suspected thoracic lesion(s) after CXR underwent DTS. Each patient underwent CT when a pulmonary non-calcified lesion was identified by DTS while CT was not performed when a benign pulmonary or extrapulmonary lesion or pseudolesion was identified. The average per-patient imaging cost was calculated by normalising the costs before and after DTS implementation. RESULTS: In 229/465 patients who underwent DTS after suspicious CXR, DTS showed 193 pulmonary lesions and 36 pleural lesions, while in the remaining 236/465 patients, lesions were ruled out as pseudolesions of CXR. Chest CT examination was performed in 127/465 (27 %) patients while in the remaining 338/465 patients (73 %) CXR doubtful findings were resolved by DTS. The average per-patient costs of CXR, DTS and CT were 15.15, 41.55 and 113.66. DTS allowed an annual cost saving of 8,090.2 considering unenhanced CT and 19,298.12 considering contrast-enhanced CT. Considering a DTS reimbursement rate of 62.7 the break even point corresponds to 479 DTS examinations. CONCLUSION: Per-patient diagnostic imaging costs decreased after DTS implementation in patients with suspected thoracic lesions. MAIN MESSAGES: • Digital tomosynthesis improves the diagnostic accuracy and confidence in chest radiography • Digital tomosynthesis reduces the need for CT for a suspected pulmonary lesion • Digital tomosynthesis requires a dose level equivalent to that of around two chest radiographies • Digital tomosynthesis produces a significant per-patient saving in diagnostic imaging costs.nonenoneE. Quaia; G. Grisi; E. Baratella; R. Cuttin; G. Poillucci; S. Kus; M.A. CovaQuaia, Emilio; Grisi, G.; Baratella, E.; Cuttin, R.; Poillucci, G.; Kus, S.; Cova, MARIA ASSUNT

Valutazione del ruolo della tomosintesi nella diagnosi delle lesioni polmonari: esperienza clinica preliminare

44\ub0 Congresso Nazionale della SIRM - Verona 11-15 giugno 201