3x3 Multibeam Network for a Triangular Array of Three Radiating Elements

A multibeam antenna study based on Butler network will be undertaken in this document. These antenna designs combines phase shift systems with multibeam networks to optimize multiple channel systems. The system will work at 1.7 GHz with circular polarization. Specifically, result simulations and measurements of 3 element triangular subarray will be shown. A 45 element triangular array will be formed by the subarrays. Using triangular subarrays, side lobes and crossing points are reduced

The degradation of p53 and its major E3 ligase Mdm2 is differentially dependent on the proteasomal ubiquitin receptor S5a.

p53 and its major E3 ligase Mdm2 are both ubiquitinated and targeted to the proteasome for degradation. Despite the importance of this in regulating the p53 pathway, little is known about the mechanisms of proteasomal recognition of ubiquitinated p53 and Mdm2. In this study, we show that knockdown of the proteasomal ubiquitin receptor S5a/PSMD4/Rpn10 inhibits p53 protein degradation and results in the accumulation of ubiquitinated p53. Overexpression of a dominant-negative deletion of S5a lacking its ubiquitin-interacting motifs (UIM)s, but which can be incorporated into the proteasome, also causes the stabilization of p53. Furthermore, small-interferring RNA (siRNA) rescue experiments confirm that the UIMs of S5a are required for the maintenance of low p53 levels. These observations indicate that S5a participates in the recognition of ubiquitinated p53 by the proteasome. In contrast, targeting S5a has no effect on the rate of degradation of Mdm2, indicating that proteasomal recognition of Mdm2 can be mediated by an S5a-independent pathway. S5a knockdown results in an increase in the transcriptional activity of p53. The selective stabilization of p53 and not Mdm2 provides a mechanism for p53 activation. Depletion of S5a causes a p53-dependent decrease in cell proliferation, demonstrating that p53 can have a dominant role in the response to targeting S5a. This study provides evidence for alternative pathways of proteasomal recognition of p53 and Mdm2. Differences in recognition by the proteasome could provide a means to modulate the relative stability of p53 and Mdm2 in response to cellular signals. In addition, they could be exploited for p53-activating therapies. This work shows that the degradation of proteins by the proteasome can be selectively dependent on S5a in human cells, and that this selectivity can extend to an E3 ubiquitin ligase and its substrate

Origin of inverse Rashba-Edelstein effect detected at the Cu/Bi interface using lateral spin valves

Under the terms of the Creative Commons Attribution License 3.0 (CC-BY).The spin transport and spin-to-charge current conversion properties of bismuth are investigated using permalloy/copper/bismuth (Py/Cu/Bi) lateral spin valve structures. The spin current is strongly absorbed at the surface of Bi, leading to ultrashort spin-diffusion lengths. A spin-to-charge current conversion is measured, which is attributed to the inverse Rashba-Edelstein effect at the Cu/Bi interface. The spin-current-induced charge current is found to change direction with increasing temperature. A theoretical analysis relates this behavior to the complex spin structure and dispersion of the surface states at the Fermi energy. The understanding of this phenomenon opens novel possibilities to exploit spin-orbit coupling to create, manipulate, and detect spin currents in two-dimensional systems.This work was supported by the European Commission under the Marie Curie Actions (Grant No. 256470-ITAMOSCINOM), the SUDOE (Grant No. TRAIN2-SOE2/P1/E-280), and the European Research Council (Grant No. 257654-SPINTROS), by the Spanish MINECO under Projects No. MAT2012-37638, No. MAT2011-13099-E, No. MAT2011-27553-C02, No. MAT2014-51982-C2-1-R, No. MAT2015-69725-REDT, and No. FIS2013-48286-C2-1-P, including FEDER funds, by the Basque Government under Project No. PI2011-1, and by the Aragon Regional Government under Project No. E26. M.I. and E.V. thank the Basque Government for Ph.D. fellowships (Grants No. BFI-2011-106 and No. BFI-2010-163).Peer Reviewe

Spin-orbit torque in Pt/CoNiCo/Pt symmetric devices

Current induced magnetization switching by spin-orbit torques offers an energy-efficient means of writing information in heavy metal/ferromagnet (FM) multilayer systems. The relative contributions of field-like torques and damping-like torques to the magnetization switching induced by the electrical current are still under debate. Here, we describe a device based on a symmetric Pt/FM/Pt structure, in which we demonstrate a strong damping-like torque from the spin Hall effect and unmeasurable field-like torque from Rashba effect. The spin-orbit effective fields due to the spin Hall effect were investigated quantitatively and were found to be consistent with the switching effective fields after accounting for the switching current reduction due to thermal fluctuations from the current pulse. A non-linear dependence of deterministic switching of average Mzon the in-plane magnetic field was revealed, which could be explained and understood by micromagnetic simulation

Simultaneous detection of the spin-Hall magnetoresistance and the spin-Seebeck effect in Platinum and Tantalum on Yttrium Iron Garnet

The spin-Seebeck effect (SSE) in platinum (Pt) and tantalum (Ta) on yttrium iron garnet (YIG) has been investigated by both externally heating the sample (using an on-chip Pt heater on top of the device) as well as by current-induced heating. For SSE measurements, external heating is the most common method to obtain clear signals. Here we show that also by current-induced heating it is possible to directly observe the SSE, separate from the also present spin-Hall magnetoresistance (SMR) signal, by using a lock-in detection technique. Using this measurement technique, the presence of additional 2nd order signals at low applied magnetic fields and high heating currents is revealed. These signals are caused by current-induced magnetic fields (Oersted fields) generated by the used AC-current, resulting in dynamic SMR signals.Comment: 9 pages, 6 figure

Synthesis of circularly polarized radial line slot array

In previous articles, an easy way to analyse a slot array fed through a radial line was presented. The analysis was based on a circuit approach where circuit parameters have been estimated using the first propagation mode in the radial line and the far field theory. Here we study the design of a particular application for circularly polarised broadside antenna. The design defines the length, position and orientation of the slots in the antenna surface. The final analysis of the antenna gives a good behaviour in field diagrams and gain

Análisis, diseño y realización de antenas planas ranuradas multisatélite

A review of designs of linearly polarized parallel-plate slot antennas developed by the authors is presented. Different combinations are described: broadside beam, one and dual tilted-beam, one and dual polarized antennas. The antenna structure, the analysis methods and the feasibility of getting a dual beam and dual linearly polarized antenna with interesting characteristics and low cost are analyzed. Several designs are proposed and their features are studied. As a conclusion, it can be said that parallel- plate slot arrays are quite promising

Diseño y construcción de antena plana de doble polarización basada en ranuras para recepción de TV por satélite

In this paper we design and make a double-polarization plane slot antenna for Digital Television Satellite reception. The prototype will fulfil the DVB specifications and furthermore it should be simple to construct and cheap. Therefore in the design process and in the implementation process exists a compromise between the specifications, low costs and simplicity