RF Transmitter/Locator

The RF transmitter/locator (TL) concept presented in this proposal enables the location and recovery of a canister such as a nose cone, artillery shell, buoy, or instrument package. The system operates over a distance of 5 mi on the surface and several hundred feet through soil, sand, or fresh water. The RF TL is battery-powered, small in size, highly shock resistant, and it consumes a minimum amount of power. It operates at a selectable frequency with a programmable delay to conserve power. While line-of-sight (LOS) communication on or above the surface requires little power and a minimal antenna, through-the-earth communications (TEC) subjects the signal to significant attenuation. The feasibility of a low-power, miniature TEC transmitter therefore depends upon optimization of the system parameters (frequency, modulation, operating mide), receiver (noise cancellation), and transmitter (antenna and power amplifier). The proposed program therefore first reviews and optimizes various aspects of the system, including near-field location techniques, VLF (TEC) link, HF(surface-to-surface) link, and transmitting antenna. It then addresses key implementation issues including transmitter organization, ASIC implementation, and receiver considerations. The end result will be a feasibility determination and preliminary design of the system and hardware for the RF transmitter/locator.