Filtenna Integration Achieving Ideal Chebyshev Return Losses

This paper demonstrates that it is possible to find an ideal filter response (Chebyshew, Butterworth,..) considering the antenna as the last resonator of a filter under certain circumstances related with the antenna performance and the bandwidth of the filtenna device. If these circumstances are not accomplished, we can achieve excellent performance as well, by means of an iterative process the goal of which is defined by either a filter mask or a classical filter function itself. The methodology is based on the conventional coupling matrix technique for filter design and has been validated by fabricating a microstrip prototype using hairpin resonators and a rectangular patch antenna

Nonlinear Performance of BAW Filters Including BST Capacitors

This paper evaluates the nonlinear effects occurring in a bulk acoustic wave (BAW) filter which includes barium strontium titanate (BST) capacitors to cancel the electrostatic capacitance of the BAW resonators. To do that we consider the nonlinear effects on the BAW resonators by use of a nonlinear Mason model. This model accounts for the distributed nonlinearities inherent in the materials forming the resonator. The whole filter is then implemented by properly connecting the resonators in a balanced configuration. Additional BST capacitors are included in the filter topology. The nonlinear behavior of the BST capacitors is also accounted in the overall nonlinear assessment. The whole circuit is then used to evaluate its nonlinear behavior. It is found that the nonlinear contribution arising from the ferroelectric nature of the BST capacitors makes it impractical to fulfill the linearity requirements of commercial filters

Searching for tidal tails around ω\omega Centauri using RR Lyrae Stars

We present a survey for RR Lyrae stars in an area of 50 deg$^2$ around the globular cluster $\omega$ Centauri, aimed to detect debris material from the alleged progenitor galaxy of the cluster. We detected 48 RR Lyrae stars of which only 11 have been previously reported. Ten among the eleven previously known stars were found inside the tidal radius of the cluster. The rest were located outside the tidal radius up to distances of $\sim 6$ degrees from the center of the cluster. Several of those stars are located at distances similar to that of $\omega$ Centauri. We investigated the probability that those stars may have been stripped off the cluster by studying their properties (mean periods), calculating the expected halo/thick disk population of RR Lyrae stars in this part of the sky, analyzing the radial velocity of a sub-sample of the RR Lyrae stars, and finally, studying the probable orbits of this sub-sample around the Galaxy. None of these investigations support the scenario that there is significant tidal debris around $\omega$ Centauri, confirming previous studies in the region. It is puzzling that tidal debris have been found elsewhere but not near the cluster itself.Comment: 11 pages, 11 figures, Accepte

Antimicrobial susceptibility of Salmonella isolated pig carriers

Ninety-six Salmonella isolates from healthy carrier pigs were obtained from a survey in pig farms of Catalonia (Spain). Isolates were serotyped and examined for their antimicrobial susceptibility against a panel of 18 antimicrobial agents. Only isolates having different phenotypic and antimicrobial susceptibility characteristics were considered. With this restriction, we considered to have 62 different strains belonging to 17 serotypes. The most common serotype was Anatum (16.1 %) followed by Rissen (14.5 %), Typhimurium (11.3 %), Derby (9.7 %), Tilburg (8.1 %), Goldcoast (8.1 %) and Typhimurium variant 4,5,12:i:- (6.5 %). Others 10 serotypes were also isolated less than three times each. Antimicrobial susceptibility analysis showed that the highest level of resistance was against tetracycline (68.8 %). Sixty-two percent of the strains showed resistance to three or more antimicrobial agents and 46% were resistant to five or more drugs. The maximum number of compounds to which two strains were resistant was 10 (corresponding to a 4,5,12:i:- strain). None of the strains was resistant to colistin or ceftriaxone and 12 strains were susceptible to all antimicrobial agents tested

The Sagittarius stream with Gaia data

The in-fall of the Sagittarius Dwarf Spheroidal (Sgr) has possibly been responsible of important perturbations on the Milky Way (MW) disk. Yet, with only some thousand of line-of-sight velocities and very few astrometric measurements, there are still many open questions regarding its orbit and stellar content, which hinders our ability to constrain its effects on the MW. We present the largest sample of Sagittarius dwarf and stream stars available to date, obtained entirely by searching in the Gaia DR2 proper motions. Thanks to a smart use of the Gaia Archive combined with the Wavelet Transform to detect substructure, we have unveiled the stream and its proper motion in an almost 360° of its path on the sky, being the more extended and continuous proper motion sequence ever measured for a stream. We have also obtained a sample of RR Lyrae in the stream for which we gain access to the distances and, therefore, to the tangential velocities for the first time. We show the main kinematic and population characteristics of the stream derived in our study. A first comparison with one of the most successful models of the stream shows significant kinematical differences with the data. Our data will allow us to study the detailed the populations of Sgr, obtain the best possible fit to the MW potential from its orbit and, in turn, constrain its impact on our Galaxy

The Halo-Disc dynamical coupling:Gaia blind detection of the Monoceros and ACS structures

The astrometric sample provided by Gaia allows us to study the disc far from the Sun, in the halo and at their interface. It is at the very edge of the disc where the effects of external perturbations is most noticeable, but also where there could be the remnants of accreted satellites. Our goal is to characterise the kinematic substructure present at the edge of the Milky Way (MW) disc to provide observational constrains that can help us identify their origin. We present the most precise characterisation of Monoceros and the Anticentre stream (ACS), detected for the first time exclusively in phase-space, without limiting ourselves to a particular stellar type. Our results allow future works to model their orbital parameters, chemistry and star formation history, to establish their origin and, ultimately, understand the most influential processes that shaped the MW over its history