Study of Acoustical Signal Transmitter Which Based on Sigma-Delta Modulation
|School||Harbin Engineering University|
|Keywords||Sigma-Delta modulation SNR Over Sampling noise shaping demodulation|
Because population explosion, went short of resource on earth and environment worsing, people began to use kinds of underwater acoustical equipments to contact, know and empolder ocean. At the same time, warfare from earth extended to ocean. Because these needs, the research in ocean exploitation and ocean battle deeper and deeper, and capability of underwater acoustical equipments liked communication sonar are demanded higher and higher. By way of the important terminal fan-out part, the capability of underwater acoustical communication are often decided by the capability of underwater acoustical transmitter. For capability higher and higher, people attempt to ameliorate the underwater acoustical transmitter. By way of a new kind of signal modulate way, Sigma-Delta modulation have many excellent characteristics on precision, SNR, EMI etc. and have prodigiouss development potential. So, the paper process the research on how to use Sigma-Delta modulation on the engineering application of underwater acoustical transmitter, named underwater acoustical signal transmitter which based on Sigma-Delta modulation.The theoretics on underwater acoustical signal transmitter which based on Sigma-Delta modulation were detailedly dissertated, including Sigma-Delta modulation, class-D power amplifier, signal demodulation, load matching, etc. Among these, sort, Over Sampling, noise shaping, working identity, stability and Idle Noise were analyzed qua keystone and found a math model. Base on the discussion and analysis of theoretics, a underwater acoustical signal transmitter which based on Sigma-Delta modulation was designed, and confirmed circuits configuration, and validated the feasibility using a series of software emulation, and accomplished the underwater acoustical signal transmitter which based on Sigma-Delta modulation which fulfil the preconcerted target. Moreover, independent experiments on stability, working frequency, delay, Over Sampling and noise shaping was accomplished, and theoretic analysis was validated.