Towards the design of a low-cost wideband demonstrator tile for the SKA

Abstract

An 8 × 7 × 2 (112 element) dual-polarized end-£re tapered-slot phased array has been designed, fabricated and tested. We demonstrate a step towards cost effectiveness without sacri£cing much of array performance. The measured mutual coupling coef£cients and the scan blindness predicted by numerical in£nite array analysis are presented. Since the antenna is entirely made out of solid aluminium, no plated-through vias are required to eliminate in-band impedance anomalies in contrast to printed bilateral Tapered Slot Antennas (TSAs). The array has been designed to operate from 0.5 to 1.5 GHz. Despite that the electrical size of the prototype array is only 5λ × 5λ (at 1.5 GHz), the location of the impedance anomalies are predicted well.

An accurate model of a wide-band microstrip feed for slot antenna arrays

“…As an example, a model for the feed has been developed for a TSA element that is being used in a potential low-cost SKA demonstrator array, known as VALARRY [4]. The TSA element is an aluminum radiator with a localized MicroStrip (MS) feed etched on a single layer printed circuit board.…”

Study and Design of a Differentially-Fed Tapered Slot Antenna Array

“…By acquiring essential knowledge from previous papers [15], [16], and by using a commercial full-wave simulator based on Finite Elements Method, named HFSS© [17], it is now possible to design these complex structures and to analyze the vitally important mutual coupling effects as these yield the wide-band performance of the array. The closely spaced elements exhibit strong mutual coupling effects which are still not modeled rigorously, so that full-wave simulations and design strategies are necessary [7], [8].…”

“…1A illustrates an exponentially tapered aperture fed by a microstrip line printed on a relatively expensive and potentially lossy substrate. Such an antenna-feed transition acts as a balancing mechanism (balun) for the differential TSA element, and is only required if a direct connection to a nondifferential transmission line has to be realized [7]. Fig.…”

“…1D illustrates a modified case compared to Fig. 1A, where the metal sheet used for the exponential taper of the aperture is no longer printed on a dielectric substrate, but realized by relatively thick metallic plates that are composed of, e.g., aluminum [7]. Finally, an example of a differentially fed TSA element, which is solely composed of thick metals, is shown in Fig.…”

Analysis of Large Microstrip-Fed Tapered Slot Antenna Arrays by Combining Electrodynamic and Quasi-Static Field Models

“…In [4], the design of a dual-polarized TSA array has been described where a dielectric substrate is employed, but only locally, and solely for the purpose of feeding each TSA [4]), which is subjected to a reduced-order modeling approach. element (see also Fig.…”