This contribution describes the design of a multibeam parabolic reflectarray to produce two adjacent beams per feed in orthogonal circular polarization (CP) simultaneously at transmission (Tx) and reception (Rx) frequencies Ka-band. The variable rotation technique (VRT) has been applied cells based on types resonant elements, which makes it possible provide Tx Rx, as well implement an in-band o...

Deformation bands (DBs), formed after plastic deformation, are known to have an impact on the recrystallization (RX) process. The exact mechanisms of how DBs influence grain nucleation and growth remain unclear. In this paper, deformed single multicrystal pure aluminium samples annealed explore likely effects subsequent growth. Regarding prediction recrystallized (RXed) texture, it is noticeabl...

Nonthermal X-rays and very high-energy (VHE) γ-rays have been detected from the supernova remnant (SNR) RX J1713.7-3946, and especially the recent observations with the Suzaku satellite clearly reveal a spectral cutoff in the X-ray spectrum, which directly relates to the cutoff of the energy spectrum of the parent electrons. However, whether the origin of the VHE γ-rays from the SNR is hadronic...

Abstract—In this paper, we discuss how the channel estimation (CE) error affects the bit error rate (BER) performance of singlecarrier (SC) block transmission using a previously proposed joint transmit/receive (Tx/Rx) frequency-domain equalization (FDE). First, the set of FDE weights is derived based on the minimum mean square error (MMSE) criterion by taking into account the CE error. The CE e...

Introduction A low power OOK transceiver for short-range wireless sensor networks (e.g. body area networks) is developed in this paper. The target receiver (RX) sensitivity and transmitter (TX) output power is -55dBm and -20dBm, respectively, assuming -25dB propagation loss at the 1-m communication distance and -5dB x 2 loss at TX/RX antennas. The target power consumption is 50μW at 1Mbps. In o...

Thanks to the high counting statistics provided by a recent XMM-Newton observation of RX J1856.5–3754 we have discovered that this isolated neutron star pulsates at a period of 7.055 s. This confirms that RX J1856.5–3754 is similar in nature to the the other six thermally emitting, nearby neutron stars discovered in soft X–rays with ROSAT. The pulsations are detected at consistent periods in se...

We observed the isolated neutron star RX J0720.4-3125 with Chandra’s Low Energy Transmission Grating Spectrometer, following the XMM-Newton discovery of long term spectral evolution of this source. The new observation shows that the spectrum of RX J0720.4-3125 has continued to change in the course of 5 months. It has remained hard, similar to the last XMM-Newton observation, but the strong depr...

Analysis of the longterm photometric variability of 7 Be/X-ray-pulsar systems in the Small Magellanic Cloud has been carried out. We find a variety of types of variability are present, including: longterm irregular changes, periodic orbital outbursts due to interaction between the stars (weeks to months), low-amplitude quasi-periodic variations of the equatorial disk (days), and nonradial pulsa...