Radio communications can avoid jamming with the use of frequency hopping.  So long as the sender and receiver radios are in sync, they rapidly hop to different frequencies in tandem.  This technology has been used by modern military forces for several years, but has not been applied to radar.     

     The latest air defense radar allows operators to switch among several different frequencies to avoid jamming.  However, modern jammers, like those used aboard EA-6Bs aircraft, can jam multiple frequencies.  As radar operators select new frequencies, the jammers detect and block, and continue to block previous frequencies to prevent switching back.  

       Frequency hopping radar would solve this problem by automatically jumping to a different frequency each second.  This is easy to synchronize because the sender and receiver exist as the same unit.  SInce electronic jammers lack the power to jam all frequencies, they may be rendered obsolete.

                                                Carlton Meyer  editorG2mil@Gmail.com

©2001 www.G2mil.com

Letters

Frequency Hopping Radar Exists

     Frequency hopping radar has existed for over 30 years!  As a former US Navy Aviation Electronics Tech ("AT"); I was an instructor on the then-new Lockheed S-3A Viking aircraft in San Diego (1973-'75) The S-3 had a multi-mode search radar with an "agile" mode, where the syncronizer/transmitter units were "synched to the receiver, and was advertised as incapable of being jammed! The system was the Texas Instruments AN/APS-116 (APS=Airborne/Pulsed/Search)
                                                   
     I believe the reason no one else uses "agile" RF exciters is because "The Evil Empire" didn't possess the technology.  We didn't sell to 3rd world banana republics, and the Soviet States never developed the technology. The Prowlers only have to perform defensive jamming against existing threat bands , not the entire defined RF spectrum!                                                                                                                                                  

                                                                                            John Nelson 

Ed.  I guess the US military doesn't advertise this technology.  I assume it is also used by Aegis radar and Patriot missile batteries, and maybe AWACS and fighters.  On the other hand, the threat of jamming is often overlooked, and I'm told frequency hopping requires much more power.  The bigger issue is that frequency hopping is not advanced technology, especially with today's low-cost computers.  If an opponent built an air defense network using frequency hopping radar, the invincible US Air Force may be blown out of the sky.