Related papers: A multi-pixel beamformer using an interferometric …
We are developing the super broad band interferometer by applying the Fourier Transform Spectrometer(FTS) to aperture synthesis system in mm and sub-mm bands. We have constructed a compact system based on the Martin and Puplett type Fourier…
Beamforming techniques have been widely used in the millimeter wave (mmWave) bands to mitigate the path loss of mmWave radio links as the narrow straight beams by directionally concentrating the signal energy. However, traditional mmWave…
Millimeter wave (mmWave) is an attractive candidate for high-speed mobile communications in the future. However, due to the propagation characteristics of mmWave, beam and and and and alignment becomes a key challenge for serving users with…
We present a large sample of high-precision, coherently-dedispersed polarization profiles of millisecond pulsars (MSPs) at frequencies between 410 and 1414 MHz. These data include the first polarimetric observations of several of the…
We present a methodology for automated real-time analysis of a radio image data stream with the goal to find transient sources. Contrary to previous works, the transients we are interested in occur on a time-scale where dispersion starts to…
Perfect alignment in chosen beam sectors at both transmit- and receive-nodes is required for beamforming in mmWave bands. Current 802.11ad WiFi and emerging 5G cellular standards spend up to several milliseconds exploring different sector…
With unparalleled rotational stability, millisecond pulsars (MSPs) serve as ideal laboratories for numerous astrophysical studies, many of which require precise knowledge of the distance and/or velocity of the MSP. Here, we present the…
The number of known millisecond pulsars has dramatically increased in the last few years. Regular observations of these pulsars may allow gravitational waves with frequencies ~10^-9 Hz to be detected. A ``pulsar timing array'' is therefore…
The Murchison Widefield Array (MWA), and its recently-developed Voltage Capture System (VCS), facilitates extending the low-frequency range of pulsar observations at high-time and -frequency resolution in the Southern Hemisphere, providing…
Context: GeV gamma-ray pulsations from over 140 pulsars have been characterized using the Fermi Large Area Telescope, enabling improved understanding of the emission regions within the neutron star magnetospheres, and the contributions of…
Emittance measurements using synchrotron radiation are usually performed using x-rays to avoid diffraction limits. Interferometric techniques using visible light are also used to measure either the horizontal or the vertical beam…
The widespread proliferation of mmW devices has led to a surge of interest in antenna arrays. This interest in arrays is due to their ability to steer beams in desired directions, for the purpose of increasing signal-power and/or decreasing…
Image quality in mosaicked observations from interferometric radio telescopes is strongly dependent on the accuracy with which the antenna primary beam is calibrated. The next generation of radio telescope arrays such as the Allen Telescope…
Dispersion in the interstellar medium is a well known phenomenon that follows a simple relationship, which has been used to predict the time delay of dispersed radio pulses since the late 1960s. We performed wide-band simultaneous…
Fast Radio Bursts (FRBs) are millisecond dispersed radio pulses of predominately extra-galactic origin. Although originally discovered at GHz frequencies, most FRBs have been detected between 400 to 800 MHz. Nevertheless, only a handful of…
Since the discovery of RRATs, interest in single pulse radio searches has increased dramatically. Due to the large data volumes generated by these searches, especially in planned surveys for future radio telescopes, such searches have to be…
Since 2004 we have been carrying out a pulsar survey of the Cygnus region with the Westerbork Synthesis Radio Telescope (WSRT) at a frequency of 328 MHz. The survey pioneered a novel interferometric observing mode, termed 8gr8…
This paper focuses on multiuser MIMO channel estimation and data transmission at millimeter wave (mmWave) frequencies. The proposed approach relies on the time-division-duplex (TDD) protocol and is based on two distinct phases. First of…
We present a numerical method for the analysis of mutual coupling effects in large, dense and irregular arrays with identical antennas. Building on the Method of Moments (MoM), our technique employs a Macro Basis Function (MBF) approach for…
We present a beamforming algorithm for multiuser wideband millimeter wave (mmWave) communication systems where one access point uses hybrid analog/digital beamforming while multiple user stations have phased-arrays with a single RF chain.…