Abstract: System for tracking mobile tags. Cell controllers with multiple antenna modules generate a carrier signal which is received by the tags. Tags shift the frequency of the carrier signal, modulate an identification code onto it, and transmit the resulting tag signal at randomized intervals. The antennas receive and process the response, and determine the presence of the tags by proximity and triangulation. The recursive-least squares (RLS) technique is used in filtering received signals. Distance of a tag from an antenna is calculated by measuring the round trip signal time. The cell controllers send data from the antenna to a host computer. The host computer collects the data and resolves them into positional estimates. Data are archived in a data warehouse, such as an SQL Server. Also disclosed is an article tracking system that supports both active and passive tags with a cell controller able to read both passive and active tag signals.

Abstract: A high power microwave or radio frequency network is disclosed which utilizes [2] two movable capacitive probes in order to provide complete vector tuning [in 4 axis by] utilizing the capacitive reactance of the two capacitive probes to provide [2] two tuning axis and the inductive reactance of two fixed inductive posts to provide [the] two additional [axis] axes of tuning, thereby allowing four axes of tuning with the movement of only two members, the capacitive probes. A third capacitive probe/inductive post set can be added to the two probe configuration for extremely high reflection correction at all phase angles.

Abstract: A capacitive sensor pad includes a foam plastic pad and heavy aluminum foil plates located to the opposite side thereof. The plates are adhesively bonded to the inner surfaces of an outer cover. The capacitor of the pad is connected in circuit with an oscillator and produces a frequency-related output. A ripple counter establishes a frequency-related output proportional to the capacitance. A microprocessor reads the counter output and a plurality of samples are averaged to establish a reference base and the true weight affect of the patient on the sensing pad. Other factors which might effect the signal are readily attended to by programmed compensation. Each subsequent sample is averaged and compared with the reference base. If within a permitted range, the latest and current signal is averaged with the reference base and establishes a new base, and continuously tracks changes in the sensing system.