An investigation is presented into the use of an electro-optical upconverti
ng modulation scheme on chirped fibre grating based true time delay lines,
and analyses made of both the amplitude and delay of detected microwave sig
nals. The bandwidth limitation of the delay line due to the fibre grating d
ispersion is clearly improved over that in conventional modulation schemes,
while the time delay performance is kept constant (sigma(max) = +/-0.9ps).