A 500 MHz Output Direct Frequency Synthesiser

First results are now available on a UHF synthesiser, which is primarily intended for radar and electronic warfare applications. The device generates square and triangle wave outputs, true and complement, phase and quadrature, over the range 1 Hz to 500 MHz. It is a fully integrated design, including two Digital to Analogue Converters (DACs) which each have a faster operating specification than any DAC currently available. The circuit is composed of a number of structured circuit blocks, each of which can be tested independently on the chip. This approach has benefits both during device evaluation and as an aid to minimising production test times.