This paper presents the design and simulated performance of an ultra-low-power 4/5 frequency divider based on a CMOS ring oscillator. The divider operates over a 189% locking range (29MHz – 1GHz) for both division ratios, covering the MICS band and 433MHz and 915MHz ISM bands while consuming only 3.3 μW in MICS band. The wide locking range and low power consumption makes this very suitable for ...

This work presents a new planar multiband antenna based on fractal geometry. This structure is optimized and validated into simulation by using CST-MW Studio. To feed this antenna we have used a CPW line which makes it easy to be incorporated with integrated circuits. The simulation results presents a good matching input impedance and radiation pattern in the GSM band at 900 MHz and ISM band at...

With the newly available SPIRE images at 250 and 500μmfrom Herschel Space Observatory, we study quantitative correlations over a sub-kpc scale among three distinct emission components in the interstellar medium of the nearby spiral galaxy M81 (NGC3031): (a) I8 or I24, the surface brightness of the mid-infrared emission observed in the Spitzer IRAC 8 or MIPS 24μm band, with I8 and I24 being domi...

Forty-two ROSAT Position Sensitive Proportional Counter pointed observations in the Ðrst quadrant (l D 4¡È26¡) of the Galactic plane are mosaicked in order to study the spatial structure of the X-rayÈ emitting gas in the Local Hot Bubble (LHB). X-ray intensity variations at various angular scales are examined in the keV band, and degree-scale variations are detected. In the context of the LHB a...

This paper presents a new collaborative mechanism for efficient coordination of radio communication devices, in particular addressing the unlicensed ISM band at 2.4 GHz. As the traffic in the ISM band is increasing tremendously, the potential for interference between uncoordinated devices is becoming a problem and can result in severe degradation of the performance of these systems. Devices usi...

Allowing WLANs to exploit opportunistic spectrum access (OSA) is a promising approach to alleviate spectrum congestion problems in overcrowded unlicensed ISM bands, especially in highly dense WLAN deployments. In this context, novel channel assignment mechanisms jointly considering available channels in both unlicensed ISM and OSA-enabled licensed bands are needed. Unlike classical schemes prop...

We present results from the observation of the young Galactic supernova remnant (SNR) G292.0+1.8 with the Advanced CCD Imaging Spectrometer (ACIS) on board the Chandra X-ray Observatory. In the 0.3 − 8 keV band, the high resolution ACIS images reveal a complex morphology consisting of knots and filaments, as well as the blast wave around the periphery of the SNR. We present equivalent width (EW...

Context. Studying the composition of dust in the interstellar medium (ISM) is crucial for understanding the cycle of dust in our galaxy. Aims. The mid-infrared spectral signature of amorphous silicates, the most abundant dust species in the ISM, is studied in different lines-of-sight through the Galactic plane, thus probing different conditions in the ISM. Methods. We have analysed ten spectra ...

With a chemically consistent evolutionary synthesis approach we follow the enrichment of individual chemical elements in the ISM. We describe the time evolution of broad band colors U to K and metal indices (Fe5335, Fe5270, Mg2, Mgb), taking into account the increasing initial metallicities of successive generations of stars. Using specific star formation prescriptions for the different spectra...

G328.4+0.2 is a moderately small (5×5) Galactic radio supernova remnant (SNR) at a distance of at least 17 kpc that has been long suggested to be Crab-like. Here we report on the detection with ASCA of the X-ray emission from the SNR. The X-ray source is faint with an observed flux of (6.0± 0.8)× 10 erg s cm over the 2–10 keV band. The emission is heavily cut-off at low energies and no flux is ...