Radar prehistory, Soviet side: three-coordinate L-band pulse radar developed in Ukraine in the late 30's

The prehistory of radar in the UK and USA is well documented, and even less known radar developments in Japan and New Zealand are known. However, early radar works in the USSR have been scarcely published, and only in Russian. Now. more than 60 years later, they can be considered as pioneering in certain aspects. Here we review the history of designing a pulse radar of the L band in the Ukrainian Institute of Physics and Technology (UIPT) in Kharkov. This work was a unique one in terms of ideas, scope, complexity of tasks, and time of completion. The basic concepts of radar design and many technical innovations were well ahead of the general trends in microwave engineering. However, at first because of political purges that smashed UIPT in the late 1930s, and then of the loss of Kharkov in the fourth month of the war, this radar had never resulted in serial production. All the official archives on this radar were lost in the war. For this reason, our study used mainly private archives of the former staff, especially of the late Alexander Usikov (1904-1995), and interview of Semion Braude (born 1911), who is the only living member of the radar team.