I’ll be presenting a paper, “On the Origins of RF-Based Location,” at the 2011 IEEE Radio and Wireless Symposium this morning at 8:00 in room Cira A. The paper collects together the pre-WWII material I’ve blogged about under the History of RF-Based Location category here at ÆtherCzar. This paper will provide […]
Lee de Forest
4 posts
A prolific inventor, Lee de Forest not only invented some of the first direction finding (DF) antenna systems, but also deserves the credit for having invented the first RF ranging system. Realizing that signal strength declines with distance, de Forest proposed inserting a variable resistor into the RF circuit to […]
John Stone Stone (1869-1943) patented the first effective direction finding system in 1902. [[1], [2]] Stone’s scheme involved a two element antenna with a first element (V) arranged no more than a half wavelength away from a second element (V’). The Figure below shows Stone’s invention. The two elements are […]
Communications may have been the first commercial application of wireless technology, but Real-Time Location Systems (RTLS) were close behind. In the first few years of radio, a variety of aggressive inventors recognized the problem of RTLS and leaped to offer solutions. Some of their ideas illustrated the inventors’ misunderstanding of […]