Efficient Filter Design to Compensate Fabrication Imperfections in 6G Communication Systems.

In this paper, we present a consistent methodology for the reliable design of 6G-oriented filters with enhanced endurance to construction imperfections. The systematic formulation does not depend on the filter's operating frequency and employs a robust strategy for obtaining new roots and poles of the filtering function. Essentially, it requires that all the local maxima of the filtering function do not fluctuate beyond the design attenuation levels for a set of predefined roots/poles distortions. To this purpose, two novel algorithms for the derivation of the appropriate filtering functions are developed, in the prior basis, together with a versatile optimization criterion and a heuristic comparison approach that guarantee optimal outcomes. Specifically, the principal idea of the first technique is to accurately extract the roots of the new polynomial from a system of equations on condition that the maximum local peaks of the distorted (due to imperfections) initial polynomial are below a prefixed threshold, such as the unit. Conversely, the second method develops an alternative polynomial, compressed in the amplitude and frequency range, so that a similar prerequisite regarding the maximum local peaks, is satisfied. It is stressed that both methods are fully generalized and may be applied to any polynomial combination, without increasing the overall complexity. The proposed framework is successfully verified in terms of theoretical examples and the numerical simulation of realistic waveguide and mictrostrip line filters, operating at frequencies from 2GHz to 65GHz, which unveil its superiority over existing schemes and implementations.

Structurally diverse metal coordination compounds, bearing imidodiphosphinate and diphosphinoamine ligands, as potential inhibitors of the platelet activating factor.

Metal complexes bearing dichalcogenated imidodiphosphinate [R(2)P(E)NP(E)R(2)'](-) ligands (E = O, S, Se, Te), which act as (E,E) chelates, exhibit a remarkable variety of three-dimensional structures. A series of such complexes, namely, square-planar [Cu{(OPPh(2))(OPPh(2))N-O, O}(2)], tetrahedral [Zn{(EPPh(2))(EPPh(2))N-E,E}(2)], E = O, S, and octahedral [Ga{(OPPh(2))(OPPh(2))N-O,O}(3)], were tested as potential inhibitors of either the platelet activating factor (PAF)- or thrombin-induced aggregation in both washed rabbit platelets and rabbit platelet rich plasma. For comparison, square-planar [Ni{(Ph(2)P)(2)N-S-CHMePh-P, P}X(2)], X = Cl, Br, the corresponding metal salts of all complexes and the (OPPh(2))(OPPh(2))NH ligand were also investigated. Ga(O,O)(3) showed the highest anti-PAF activity but did not inhibit the thrombin-related pathway, whereas Zn(S,S)(2), with also a significant PAF inhibitory effect, exhibited the highest thrombin-related inhibition. Zn(O,O)(2) and Cu(O,O)(2) inhibited moderately both PAF and thrombin, being more effective towards PAF. This work shows that the PAF-inhibitory action depends on the structure of the complexes studied, with the bulkier Ga(O,O)(3) being the most efficient and selective inhibitor.