Our aim is to develop a microwave antenna whose radiation pattern is electronically controlled. The radiation pattern of regular antennas is determined by the Fourier-transform of the complex illumination function on the antenna aperture. This radiation pattern is mechanically fixed so its alteration is impossible. Therefore we construct an antenna system of several antenna elements. All elemen...

Studies conducted by the Cambridge Radio Observatory Committee during the past two years show that a large steerable telescope can be constructed at lower cost and with higher precision if the antenna is protected from the environment by a radome. These studies also indicate that the extremely high pointing precision (10 arc-sec) needed to make effective use of a large aperture at wavelengths a...

Near-field transducer based on nanoscale optical antenna has been shown to generate high transmission and strongly localized optical spots well below the diffraction limit. In this paper, nanoscale ridge aperture antenna is considered as near-field transducer for heat-assisted magnetic recording. The spot size and transmission efficiency produced by ridge aperture are numerically studied. We sh...

Densely-packed, all-digital aperture arrays form a key area of technology development required for the Square Kilometre Array (SKA) radio telescope. The design of real-time signal processing systems for digital aperture arrays is currently a central challenge in pathfinder projects worldwide. We describe an hierarchical, frequency-domain beamforming architecture for synthesising a sky beam from...

This paper describes the design and testing of an aperture-coupled circularly polarized antenna for global positioning satellite (GPS) applications. The antenna operates at both the L1 and L2 frequencies of 1575 and 1227 MHz, which is required for differential GPS systems in order to provide maximum positioning accuracy. Electrical performance, lowprofile, and cost were equally important requir...

1 LO, T.K : 'Miniature aperture-coupled microstrip antenna of very high permittivity', Electron. Lett., 1997, 33, pp. 9-10 2 PINHAS, s., and SHTRIKMAN, s.: 'Comparison between computed and measured bandwidth of quarter-wave microstrip radiators', IEEE Trans., 1988, AP-36, (ll), pp. 1615-1616 3 WATERHOUSE, R.B : 'Small microstrip patch antenna', Electron. Lett., 1995, 31, pp. 604605 4 LUK. K.M.,...

The design of a new L-band antenna for DLR’s airborne synthetic aperture radar system (E-/F-SAR) is presented. Beside operations in L-band new components for a system upgrade were developed. These components are introduced. Special interest of this paper is the development of the dual-polarized L-Band antenna with enhanced bandwidth of 150MHz. The antenna feed network is equipped with 2bit hybr...

One of the most challenging problems in recent antenna engineering fields is to achieve highly reliable beamforming capabilities in an extremely restricted space of small handheld devices. In this paper, we introduce a new perspective on single-radiator multiple-port (SRMP) antenna to alter the traditional approach of multiple-antenna arrays for improving beamforming performances with reduced a...

Microstrip-line-feeding waveguide aperture antenna is developed in the 70-90 GHz band. A double-layer LTCC substrate is attached to the waveguide aperture opened on the wall of the metal package. The bandwidth over 20 GHz is observed in the simulation and the experiment.

■ The challenge of precision source location with a radio-frequency antenna array has existed from the beginnings of radiometry and has continued in modern applications with planar antenna arrays. Early work in this field was limited to estimating single source directions in one dimension with systems like crossed-loop radiometers. Currently, more advanced systems attempt to estimate azimuth an...