I have 5 radar history books I would recommend. The first is the most technical tome - and rarest. The last two are more historical reminiscences of operators. The last is a part of the history of RAF GCI little known, a mobile radar advancing through Normandy and France to the Rhine - sometimes finding themselves on a hilltop between the lines!
Technical History of the Beginnings of Radar; S.S. Swords, Peter Peregrinus Ltd on behalf of the Institute of Electrical Engineers. ISBN 0-86341-043-X
A Radar History of World War II - Technical and Military Imperatives; Louis Brown, Institute of Physics Publishing Bristol and Philadelphia. ISBN 0-7503-0659-9
The Invention that Changed the World; Robert Buderi, Simon Schuster. ISBN 0-684-81021-2
Radar - A Wartime Miracle; Colin Lataham and Anne Stobbs, Alan Sutton Publishing Ltd. ISBN 0-7509-1114-X
Off to War with "054", John Kemp, Merlin Books Ltd. ISBN 0-86303-459-4