SAW quadrature binary modulation system applications

摘要

A surface acoustic wave (SAW) modulation system has been built, using a combination of a digital message sequence, an impulse driver, and different SAW modulator filters, for experimental testing of a wide variety of quadrature binary modulation schemes. The RF testbed is described and characterized for system distortion, dynamic range, and spurious responses, and system optimization is discussed. Nine different SAW modulator filters having different time- and frequency-domain responses were designed and fabricated for use in the system. Several of the designs are representative of new modulation schemes which offer better spectral confinement; and time-domain envelope uniformity than MSK. The results obtained with the designed SAW quadrature binary modulation system are presented. Excellent agreement between time- and frequency-domain measurements and theoretical predictions using the SAW modulation system are shown.