Abstract
The development of a high frequency (115 kHz and 350 kHz) underwater acoustic communication modem is reported. The transmit and data acquisition components have been designed for phase-modulated waveforms, intended to be computationally simple, power efficient and cost effective. Applicability to other types of waveforms will be discussed. The design incorporates a digital signal processor, an efficient power amplifier, an analog to digital converter, and broadband transducers. An electrical equivalent circuit of the transducer was constructed as an accurate test load for bench-top measurements. Modeled results are compared to in-water test tank measurements with broadband transducers. The system is intended to serve as a development and demonstration platform to test novel waveforms and serve as a communication system on unmanned underwater vehicles (UUVs).