Medical imaging is of great importance for patients affected by stroke. Since an early examination of the patient is necessary for successful recovery, there is room to improve the existing capabilities of analysis. Common systems like magnetic resonance imaging or computed tomography are precise, but stationary, and therefore, not ideally suited for the early analysis of stroke. The presented multiport vector network analyzer system uses electromagnetic tomography (EMT) as an alternative imaging technique. It consists of a network of distributed electronic sensor nodes which improve important parameters: the parallel measurement setup reduces the measurement time as low as 160 ms for a 200-port S-parameter matrix and it is capable of measuring signal levels down to − 150 dBm. The electronics allow a compact, movable packaging, leading the way for future portable devices. The detection of stroke models was examined by test measurements of a phantom. The data was analyzed by the help of an inverse reconstruction algorithm. The possibility of building portable setups which can be even applied to patients inside an ambulance, makes EMT a suitable alternative for early stroke detection. It can help in shortening the recovery of patients, by providing an early analysis of the brain.
This paper proposes a fully integrated 160-GHz transmitter and receiver in package for millimeter-wave applications. The monolithic integrated circuits were designed with a harmonic approach and were fabricated using a SiGe:C HBT production technology with an fTand fmaxof 170 and 250 GHz, respectively. The manufactured 2006 × 1865 µm2bare dies were integrated in 6 × 6 mm2embedded wafer level ball grid array packages, where they were interconnected with highly directional antennas built on the redistribution layer of the packages. With a total frequency multiplication factor of 36 and an active balun at the first stage, the transmitter allows the use of a 4.5-GHz input signal driven from a single-ended signal source [1] and distributed on a standard low-cost printed circuit board. The receiver comprises a Gilbert-cell-based subharmonic mixer with a simulated 1-dB input compression point of −4 dBm, and a minimum double-sideband noise figure of 16.5 dB. The functionality of the proposed system was successfully demonstrated in a quasi-monostatic FMCW radar measurement with a 1-ms up-chirp frequency sweep from 157 to 160 GHz and in a forward-scatter imaging experiment with an 8-GHz frequency ramp from 157 to 165 GHz.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.