Differential charge amplifier for marine seismic streamer - has resistance-capacitance feedback amplifiers and differential stage

摘要

The differential charge amplifier is intended for use in towed marine seismic streamers and the like involving towed hydrophone arrays in which the hydrophone outputs are conducted by long twisted pairs of leads to signal processing equipment. The differential charge amplifier includes operational amplifiers connected to form charge amplifier stages having resistance-capacitance feedback circuits and a differential amplifier stage coupled to the charge amplifier outputs providing cancellation of common mode signals. The positive inputs of the operational amplifiers are earthed and the feedback keeps the negative inputs at earth potential, so variations in shunt capacitance do not affect signal response.