Kahn’s Kahn-Hazeltine AM Stereo design was an independent sideband system that used independently modulated upper and lower sidebands.
One of the best known stations to use the Kahn system was WLS-AM Chicago. His system remained competitive with Motorola’s C-QUAM system into the late 1980s. Kahn filed a lawsuit claiming the Motorola system didn’t meet FCC emission bandwidth specifications, but by that time, C-QUAM had already been declared as the single standard for AM stereo in the US.
Kahn’s AM stereo design was later revamped for mono use and used in the Power-Side system, in which a decreased signal in one sideband is used to improve coverage and loudness. Power-Side became the basis for CAM-D, Compatible AM Digital, a digital system that is still used on several AM stations.
Kahn worked for RCA Labs for many years and turned out over 80 patents (and over 100 foreign patents), many with regard to AM broadcast technology. He is considered one of the five “fathers of the wireless industry.”
Kahn, WB2SSP, was a former Adjunct Professor of Electrical Engineering and was a Registered U.S. Patent Agent and has argued a number of times before the U.S. Court of Appeals for the Federal Circuit. He litigated successfully against General Motors and Motorola, representing himself in the Southern District of New York, The Court of Appeals for 2nd Circuit and the Federal Court of Appeals in Washington, DC.
He was a Fellow of the IEEE and of RCA. He received the RCA’s Armstrong Medal (1980), and was the initial recipient of the RCA’s Jack Poppele Broadcast Award (1989).
In 1997 the United States District Court for the Southern District of New York ruled that Kahn had title to US patent #4,018,994 in a suit. He sued General Motors and won for infringement of that patent for its use of AM stereo in car radios.
[We’ve later learned he actually lost both suits brought against Motorola and GM; including the 1994 patent infringement case in Federal court, Southern District of NY. He won some early rulings on procedure but neither the jury or bench trials.]
Kahn also filed a lawsuit in federal court in New York in 2006 alleging that iBiquity Digital, Lucent and Clear Channel violated antitrust laws with the implementation of the iBiquity AM HD Radio (IBOC) system. Kahn said in the complaint that they had formed a broadcast cartel seeking to block others from buying his CAM-D system. That suit was not heard by the Supreme Court on appeal.
In 2009, Kahn filed a complaint with the Southern District of NY Court (Civil Action 08-CV-11368), charging major investment banks and The City of New York and Mayor Bloomberg, personally. He named Oppenheimer & Co. specifically for falsely swearing that he was “senile” because he issued three $10,000 checks and two of them bounced. Kahn says the checks shouldn’t have bounced because he had documents (attached in the suit) that proved that he had over $350K in just one account. In the case, Kahn also sued Wachovia, SunTrust and TD Ameritrade for allegedly “converting” his fortune (he told RBR that in 2008 he claimed $16 million in assets).
Kahn’s suit also asked for emergency relief to hold the NYC Dept. of Social Services from extending their “chase” to his Long Island lab (Kahn Communications) which halted his work on a solution for Homeland Security—the “iSAFE” system. iSAFE would the CAM-D system to alert citizens in an emergency. A small receiver chip would be incorporated into cell phones, Blackberrys, iPhones, iPods, laptops, etc. that would warn of an emergency to citizens that might otherwise be unable to get to a TV or radio—or might not even hear what is going on because they’re “isolated” by headphones, etc. The goal is to bring emergency alerts when the cell phone networks are overloaded and the Internet may be too congested to work (also from a potential cyber-attack). Kahn said CAM-D is robust enough to penetrate buildings, parking garages, etc.
We believe that case was dismissed before going to trial. Leonard’s wife Ruth preceded him in death and the couple had no children.