RF transmitter uses AMI encoding

摘要

Although alternate-mark-inver- sion (AMI) encoding is well-suited for direct-conversion FM transmission, designers often overlook the technique. AMI, a three-phase, synchronous-encoding technique, uses bipolar pulses to represent logic ones and no signal to represent logic zeros (Figure 1). Direct-conversion FM transmission, in which data directly modulates a carrier, is also known as frequency-shift-keying (FSK) modulation.