Abstract: A pulse-listen electronic article security (EAS) system for detecting the presence of a security tag within a detection zone is disclosed. The EAS system includes a transmitter for radiating a first electromagnetic signal into the detection zone. The first electromagnetic signal is a time sequence of RF bursts emitted during each of a plurality of contiguous frame intervals in which the duration of each of the frame intervals is one of a plurality of different values. The EAS system also includes a receiver synchronized with the transmitter for receiving a second electromagnetic signal re-radiated from a security tag in the detection zone in response to the first electromagnetic signal. The receiver provides an output signal if a security tag is detected.

Abstract: Noise reduction schemes are provided in a radio frequency identification (RFID) system for use with RFID intelligent tags. Amplitude and phase noise is minimized by starting with a low noise crystal oscillator having an output frequency which is an integer multiple n of the desired RF field frequency, and then dividing this frequency by the integer multiple n. One or more cascaded flip-flops are used for the frequency dividing. Both outputs of the final stage flip-flop are used to drive the transmitter antenna to produce a continuous wave signal.

Abstract: A system which enables transmission of a standard composite stereo sound signal, made up of baseband, subcarrier band and pilot signals, from a first location to a second location while requiring only a relatively low bit rate for the transmission link. The standard composite stereo signal is synchronously sampled at a first location at rate F.sub.s twice the subcarrier frequency F.sub.c (four times the pilot frequency F.sub.p), and the sampled signal transmitted over the link along with appropriate synchronizing signals. At the second location, a signal processor separates the received signal into a first signal related to one stereo channel signal (e.g. R) and a second signal representative of the other stereo channel (e.g. L), determines the proper scale for the pilot signal, and regenerates the original standard composite stereo sound signal by combining the L-related and R-related signals with the pilot scale signals in appropriate proportions and with appropriate filtering.