Abstract: An RFID tag includes taggents which reflect at selected frequencies or tones. For each byte of information to be associated with an item to be tagged, a reflective tone range is assigned. Within the tone range of each byte, a bit is represented by a subband range, where a reflective tone in any subband range represents a logic 1 state of that bit. To represent a bit, one of the reflective tones in the subband is randomly chosen. The data carried by the tag may include checksum information carried in further tone range. The randomly assigned subband selected for each item(s) is recorded, and the recorded information accompanies a group of tagged items. Reading tagged items involves tone scanning the tags and using the resulting reflective tones and the recorded information to determine which items are present.

Abstract: A method according to an aspect of the invention is for filtering coherent multipulse radar, sonar or lidar returns. The method comprises the steps of separating the returns into mutually orthogonal I & Q components, performing wavelet processing on the I and Q components to generate an I & Q wavelet filter output. The I & Q wavelet filter outputs are data compressed to remove clutter portions. Data compression may be removal of large-amplitude or earliest wavelet responses. An inverse wavelet filtering function is performed on the compressed wavelet filter outputs, to thereby generate edited coherent I & Q components. Doppler filtering, is performed on the edited coherent I and Q components to thereby generate frequency-domain target data in which the minimum discernible target velocity is improved.

Abstract: A radar system which uses an active phased-array antenna achieves improved clutter improvement factor (CIF) by powering the various transmit-receive (TR) modules of the antenna with direct voltage (DC) derived from a plurality of phases of the power-line alternating current (AC). Each TR module receives power which originates with one phase of the source AC. The phases are selected so that the modulation of the radio-frequency (RF) signals by each TR module tends to cancel in the summed signal from the array antenna.