For those who are interested in knowing more about how radar & EW works...
http://www.microwaves101.com/encyclopedia/Navy%20handbook/EW_Radar_Handbook.pdf
There was an old Reader's Digest print revealing that in the 1950s, the US Embassy in Moscow was bombarded by an array of microwave dishes that were listening device for the KGB.
The microwave dishes were placed on all sides of the US Embassy - all directed towards any possible rooms where interesting conversation can be eavesdropped by being picked-up via the microwave dishes.
A 12 year study made a belated discovery of an unusual high incidence of cancer occurring in the US Embassy staff returning from the US Embassy in Moscow.
The US Embassy staff were all being microwaved 24 / 7
The immediate reaction taken was to have the US Embassy lined its internal walls with "lead material" to block the microwave from penetrating the brick walls.
‘The Invisble Third World War’.
Ah... a bit not related to radar and EW that slim brought up. Still nice to know though.
The idea of radar jamming is actually pretty simple, even though the manual offers a very thorough explanation. In its most basic form, its about degrading the signal to noise ratio from the jammed-radar's perspective. Its when ECCM is involved that complications in ECCCM arises. Eg, the radar may use different frequencies so that the jamming will be ineffective, then jammers also develop countermeasures to jam the new frequencies.
Jamming every known frequency of a particular radar type (known as "barrage jamming") is a good idea but decreases the effectiveness of the jammed signals as the power output is now distributed across a broad spectrum of frequencies. Those are rather defensive sense of jamming.
Offensive Jamming is different in that instead of just flooding the area around the aircraft with noise, the noise is now funneled and pointed directly at the radar to be jammed. The range of offensive jamming is greater in that its directed and more concentrated into a beam instead. A radar thats being offensively jammed by a EA-6 or old Sparkvarks, is pretty much screwed and unable to do much.