Abstract: The present invention presents a closed loop system that utilizes a non-linear reference to control a power amplifier's output power in order to obtain a linear transfer function of dB per adjustment step of a reference input. The closed loop system demonstrates that each non-linear stage/step in an automatic gain control system can create a linear closed loop system when using a non-linear reference. The closed loop system of the present invention eliminates the need for a linearization circuit for the system's power detector. The closed loop system may be used with most power amplifiers when linear control in terms of dB vs. adjustment setting of the input reference signal is desired. Output power in terms of dBms can be accurately set in linear steps where power control over a wide dynamic range is desired.

Abstract: A meter reading system preferably includes an external modem module (EMM), a hub and a data collection system. The EMM communicates with one or more utility meters and, as such, is preferably selected on the basis that it incorporates a communication format that is compatible with the communication format of the utility meter such that the utility meter does not require modification to be communicatively coupled to the EMM. The EMM obtains meter data from the utility meter and converts to a radio frequency communication format. The radio frequency formatted data is then transferred to the hub. The hub then translates the radio frequency data into an analog or digital telephone communication format, which is then transferred to the data collection system for use by the utility as desired, e.g. utility billing, tracking, control, etc.

Abstract: A low-cost emergency locator beacon (ELB) device that transmits an identifying serial number in addition to the beacon signal. This transmission includes an audio modulated Manchester encoded digital version of the serial number, and an analog, voice synthesized version of the serial number. In one embodiment, the device incorporates a receiver that enables the user of the device to enter into two-way, direct voice communication with a rescuer. The device also includes an automatic receive function which facilitates operation of the device by users not aware or not able to operate the device. In another embodiment, the ELB device includes an inhibit function which prevents non-emergency, ELB device to ELB device communication.

Abstract: A system for synchronizing a signal at a remotely located slave station with the phase and frequency of a signal generated at a master station. The signal transmitted at the master station and received by the slave station provides compensation for the phase shift caused by the transmission path delays between the master and slave station. The slave station transmits a signal to the master station at a frequency that is different from the frequency of the signal being transmitted by the master station. The signal transmitted by the slave station is received by the master station while the master station transmitter is off. The signal transmitted by the master station is received by the slave station while the slave station transmitter is off.