A 2 kHz-100 MHz dynamic amplifier for tracking targets of variable amplitude

A 2 kHz-100 MHz constant-output dynamic amplifier design is presented. Appl ication of the amplifier is shown for tracking wireless magnetoelastic and magnetoacoustic environmental sensors [C. A. Grimes , Rev. Sci. Instrum. 70 , 4711 (1999); K. Loiselle and C. A. Grimes, Rev. Sci. Instrum. 71, 1141 (2 000)], the detected amplitude which varies significantly with spatial locat ion from the detector. The amplification of the dynamic amplifier, 80 dB, i s controlled by inverted feedback voltage; the design is suitable for an in put voltage range of -150 to -10 dB. The dynamic amplifier enhances the det ection range of magnetoacoustic sensors by an approximate factor of three, and that of magnetoelastic sensors by a factor of 1.25, with the magnetoela stic sensors having comparatively less detection range increase due to high er background noise levels. (C) 2001 American Institute of Physics.