[Prev][Next][Index][Thread]

Radar gun jammers



Jonathan: I'm a computer engineer, but that's close enough to an electrical 
engineer to have covered a lot of the same material in school. From what I 
know, there really isn't a good, inexpensive passive way to defeat a radar 
gun - their beam usually will hit a front rotor, windshield, or engine 
block and get a pretty good reflection. The designers of stealth aircraft 
have to jump through some pretty tough hoops to make an aircraft that has 
all it's metal parts deep inside it and that doesn't have any surfaces that 
are angled where they'll reflect a signal well. There's an interesting 
article in the August '86 issue of Radio-Electronics (now called 
Electronics Now) that has plans for an active radar "controller". Basically,
 what it does is transmit (illegal without the proper FCC license) a signal 
stronger than the reflection from your car that's at the proper frequency 
to cause the radar gun to read whatever you'd like. The plans are old and 
only cover x-band, but it wouldn't be too hard to update. The bad news is 
that the Gunn diodes used to produce the signal cost around $80 each - so 
if you wanted to do front and rear, x and k band would cost $240 just for 
the diodes! (They might be cheaper now, I priced them back in '91 after an 
expensive ticket). If you're interested, I'll fax you a copy of the plans, 
if nothing else, it does a very good job of explaining how radar works. 

Barrett Nicholas