Design of corrugated horns: a primer

Granet, C.; James, G.L.

doi:10.1109/map.2005.1487785

Cited by 140 publications

(83 citation statements)

References 11 publications

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“…At 20 cm, observations are mostly made using the centre beam of the Parkes multibeam receiver (Staveley-Smith et al 1996) but occasionally with the 'H-OH' receiver when the multibeam receiver is not available. Observations at 10 and 50 cm are made using the dual-band coaxial '10 cm/50 cm' receiver (Granet et al 2005). Details of these receivers are given in Table 1, where f c is the nominal band centre and S sys is the system equivalent flux density.…”

Section: Telescope and Receiver Systemsmentioning

confidence: 99%

The Parkes Pulsar Timing Array Project

Manchester

Hobbs

Bailes

et al. 2013

Publ. Astron. Soc. Aust.

449

283

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A 'pulsar timing array' (PTA), in which observations of a large sample of pulsars spread across the celestial sphere are combined, allows investigation of 'global' phenomena such as a background of gravitational waves or instabilities in atomic timescales that produce correlated timing residuals in the pulsars of the array. The Parkes Pulsar Timing Array (PPTA) is an implementation of the PTA concept based on observations with the Parkes 64-m radio telescope. A sample of 20 ms pulsars is being observed at three radio-frequency bands, 50 cm (ß700 MHz), 20 cm (ß1400 MHz), and 10 cm (ß3100 MHz), with observations at intervals of two to three weeks. Regular observations commenced in early 2005. This paper describes the systems used for the PPTA observations and data processing, including calibration and timing analysis. The strategy behind the choice of pulsars, observing parameters, and analysis methods is discussed. Results are presented for PPTA data in the three bands taken between 2005 March and 2011 March. For 10 of the 20 pulsars, rms timing residuals are less than 1 μs for the best band after fitting for pulse frequency and its first time derivative. Significant 'red' timing noise is detected in about half of the sample. We discuss the implications of these results on future projects including the International Pulsar Timing Array and a PTA based on the Square Kilometre Array. We also present an 'extended PPTA' data set that combines PPTA data with earlier Parkes timing data for these pulsars.

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Section: Telescope and Receiver Systemsmentioning

confidence: 99%

The Parkes Pulsar Timing Array Project

Manchester

Hobbs

Bailes

et al. 2013

Publ. Astron. Soc. Aust.

449

283

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“…The input waveguide only needs to be excited by quite pure TE 11 mode, which has dissymmetrical copolarization field in the E-plane and Hplane. The mode converter is required to finish the TE 11 -to-HE 11 mode conversion over a specified number of slots with a choice of variable-depth slot, ring-loaded slot, or variablepitch-to-width slot [15,34]. The theoretical knowledge comes from the circular waveguide mode in the horn aperture that can be achieved into the balance condition with hybrid mode that has zero cross-polar field and is marked as HE 11 similar to 85% × TE 11 + 15% × TM 11 approximatively, when the deep of slots changes from λ/2 to λ/4 at the center frequency [35][36][37].…”

Section: The Corrugated Feedmentioning

confidence: 99%

“…It can finish a transformation of circular waveguide mode from fundamental TE 11 mode to balanced hybrid HE 11 mode in the horn aperture, where the aperture field has the characteristics of very low crosspolarization level and circular symmetrical radiation pattern with Gaussian distribution characteristic [14][15][16][17]. In the higher frequency band, limited by high machining accuracy in the grooves and junction, the machining quality of corrugated horn can easily affect its far-field pattern that leads to nonuniformity symmetrical Gaussian distribution due to the decreasing of main mode HE 11 .…”

Section: Introductionmentioning

confidence: 99%

Theoretical and Experimental Comparison Results of Dual-Channel 3D Quasi-Optical Network System between Frequency Selective Surface and Wire Grid Polarizer

Hai

Liu

et al. 2018

International Journal of Antennas and Propagation

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A dual-channel 3D quasi-optical network (QON) system is analyzed and compared by theoretical and experimental results. It is divided into dual-channel signals by frequency selective surface (FSS) or wire grid polarizer (WGP) for transmitting the 324 GHz signal on the top layer while diverting the 183 GHz signal to the bottom layer. The system structure based on the beam radius is traced by the complex beam parameter and system transfer matrix for deciding the positions of cascade mirrors. The design principles and test results of FSS with perforated hexagonal array and WGP printed on the dielectric substrate are discussed together. In order to evaluate channel performance, the output planar near-fields of QON system are simulated and tested by the four reflections and three transmission results, respectively, where both scalar and vector conversion efficiencies are used to evaluate the quality of output beams. For the distortion phenomenon and energy loss in planar field, the aperture modes of corrugated horn feeds are analyzed by spherical wave expansion (SWE) to explain the asymmetrical pattern characteristic. The cut section of the far-field pattern is also directly measured in the compact antenna test range (CATR), comparing with the far-field patterns that are indirectly obtained based on the principle of near-to-far-field transformation and ideal aperture field integral of quiet zone (QZ). The differences between the near-and far-field test in QON have been compared, and discussion that the corresponding experimental results verify the WGP has better work performance in the good pattern symmetry, high cross-polarization isolation, low energy loss, and side-lobe level.

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“…the radiometer relation, which predicts κ = 4.23 × 10 −3 for 320 MHz of bandwidth. The dual-band 10/50 cm (Granet et al 2005) observing system we used has a system equivalent flux density (SEFD) of 25-30 Jy over the observing band, and the peak intensity of Vela reaches about 9 Jy (mean about 220 mJy). Thus, for a typical pulse, the system noise level is only increased by about 5% at peak, a negligible effect.…”

Section: Observationsmentioning

confidence: 99%

Improving pulsar timing precision with single pulses

Kerr

2015

Mon. Not. R. Astron. Soc.

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The measurement error of pulse times of arrival (TOAs) in the high S/N limit is dominated by the quasi-random variation of a pulsar's emission profile from rotation to rotation. Like measurement noise, this noise is only reduced as the square root of observing time, posing a major challenge to future pulsar timing campaigns with large aperture telescopes, e.g. the Five-hundred-metre Aperture Spherical Telescope and the Square Kilometre Array.We propose a new method of pulsar timing that attempts to approximate the pulse-to-pulse variability with a small family of 'basis' pulses. If pulsar data are integrated over many rotations, this basis can be used to measure sub-pulse structure. Or, if high-time resolution data are available, the basis can be used to 'tag' single pulses and produce an optimal timing template. With realistic simulations, we show that these applications can dramatically reduce the effect of pulse-to-pulse variability on TOAs. Using high-time resolution data taken from the bright PSR J0835−4510 (Vela), we demonstrate a 25-40% improvement in TOA precision. Crucially for pulsar timing applications, we further establish that these techniques produce TOAs with gaussian residuals.Improvements of this level halve the telescope time required to reach a desired TOA precision. Although some gains can be achieved with existing data, the greatest improvements result from the 'tagging' approach, which in turn requires online or posthoc analysis of single pulses, an important consideration for the design of future instrumentation.

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Design of corrugated horns: a primer

Cited by 140 publications

References 11 publications

The Parkes Pulsar Timing Array Project

The Parkes Pulsar Timing Array Project

Theoretical and Experimental Comparison Results of Dual-Channel 3D Quasi-Optical Network System between Frequency Selective Surface and Wire Grid Polarizer

Improving pulsar timing precision with single pulses

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