High Frequency as a Weapon This is a two-part period training film that describes how the network of German Luftwaffe radar installations detected enemy squadrons and directed local fighter interceptors against them. The second part describes radar jamming techniques. To my knowledge, this is the only period documentary which exists on the subject matter.
Battle of The Beams
This five-part British documentary describes the seldom discussed subject of radio navigation beams, originally employed by the Germans to target cities in the United Kingdom for night-bombing raids.
Part 1
Part 2

Part 3

Part 4

Part 5