Recent advances on the design of random sparse arrays made from Log-periodic antenna elements for the SKA AA-Mid instrument

In this paper we present the recent advances on the design of sparse arrays using log-periodic antennas for the SKA AA-Mid instrument. The SKA AA-Mid instrument will explore the southern hemisphere sky from ~400 MHz up to 1.4 GHz with unprecedented sensitivity and survey speed. Large collecting area, low system noise and great survey speed are key to achieve the demanding requirements of the SKA. The University of Cambridge proposes designing this instrument as a collection of stations, each of them being a random sparse array of ultra wideband log-periodic antennas. The advantage of this approach, amongst others, is the increasing collecting area with wavelength (as a square of the wavelength) that sparse arrays offer over dense arrays, and which facilitates the realization of the SKA science goals. We have now advanced our developments to study the system implications of this decision and have started the design of a 16-element prototype array that will be located at the MRAO Observatory at Lords Bridge, Cambridge, UK. This array will help us progress our developments.