RF Cancellation Circuit for Shore-Based VHF FM Transceiver.

摘要

The purpose of this research and development program was to develop an optimized method of removing unwanted transmitted signals from the receiver path in a typical Coast Guard VHF FM transceiver station. The circuit developed allows continuous monitoring of the guard channel (Ch. 16, 156.8 MHz) with minimum background interference levels while transmissions are occurring from the same antenna on adjacent channels spaced as close as 150 kHz. The six-month program was divided into four phases: (1) Components and Circuit Technique Identification and Analysis; (2) Performance Evaluation of Candidate Components and Circuit Techniques; (3) System Field Tests; and (4) Specification and Documentation of Program Results.