'...Sivan's book is a most welcome addition to the small group of new publications on microwave tubes...Sivan has achieved an admirable balance between breadth and depth of coverage and has written a book which is packed with a wealth of practical information...It is hard to find any matter connected with microwave tubes and their applications which does not receive at least a brief mention with a supporting reference...Overall this is an excellent book which will be valued as a vork of reference by both systems engineers and tube manufacturers. It should be compulsory reading for all those who still believe the myths about vacuum tubes.' Electronics and Communication Engineering Journal ' ...the author is to be commended for bringing together such a mass of valuable information. The book is well illustrated and contains many further references.' Electrotechnology