Milestone 9.1: First exciter prototype in operation

As part of this Work Package, a single-channel exciter comprising AD9957 evaluation board, a broadband MMIC RF amplifier and a command interface has been designed and prototyped. The interface contains a baseband data PROM, programmed with a set of I/Q data defining eight points on the periphery of the unit circle ([0,...,7]×45°) which can be selected at will by external command. The prototype has been debugged and verified by using three bits from the EISCAT Radar Controller to control the PROM, feeding the resulting analog output signal at ≈108 MHz into the first i.f. of the Kiruna EISCAT UHF receiver and sampling and displaying the signal using a special purpose experiment running under EROS.

Report on the design of the digital exciter

The output signal is phase-stable to better than one part in 10¹¹ over 5 seconds; the phase progression when stepping through the eight possible phases is repeatable to within the resolution of the measurement system over the same time period. The first operation of this prototype exciter constitutes Milestone 9.1.

This Milestone was reached in May 2011.