Abstract: An analog continuous wavelet transform circuit is implemented using a bank of quadrature voltage controlled oscillators (VCOs) and a bank of synchronous receivers. The synchronous receivers act as a bandpass filter bank, the center frequency of each synchronous receiver bandpass filter being set by the frequency of a corresponding VCO. Each quadrature VCO generates differential in-phase. (I) and quadrature (Q) outputs, and has a multiplier, gain amplifier/low-pass filter, and a squarer for both I and Q phases, and the squarer outputs are summed to produce the synchronous receiver output. Each synchronous receiver output represents the instantaneous input signal power within a specific bandpass filter bandwidth filter. The center frequency of the bandpass filter is determined by the VCO frequency, and the bandpass filter bandwidth is set by the synchronous receiver low-pass filter bandwidth.
Type:
Grant
Filed:
January 8, 2001
Date of Patent:
September 10, 2002
Assignee:
The United States of America as represented by the Secretary
of the Navy