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.