Jose Alberto Lopez-Fernandez

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Scan impedance anomalies are associated to phased arrays. There are different phenomena in order to explain these scan blindnesses produced when the array scans at one frequency and one angle. The most popular technique for eliminating these scan blindnesses is based on the use of electric walls in the grid of the two dimensional array. In this paper we(More)
The design and construction of a full-bridge flying capacitor multicell inverter (FCMI) composed by two legs is disclosed. Each leg comprises three switching cells. In order to control the power converter a square wave signal switching technique has been used; the converter output frequency has increased at three times the switching frequency. Moreover, the(More)
This paper shows the design, construction and characterization of an ultra-low noise and broad-band receiver system, to be used for geodetic very long baseline interferometry (VLBI) observations with the Spanish new 13.2 meter radiotelescopes, in the frame of the VLBI Global Observing System (VGOS). The cryogenic receiver front-end covers the frequency(More)
Cyanogen (NCCN) is the simplest member of the series of dicyanopolyynes. It has been hypothesized that this family of molecules can be important constituents of interstellar and circumstellar media, although the lack of a permanent electric dipole moment prevents its detection through radioastronomical techniques. Here we present the first solid evidence of(More)
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