STC processing for chirp transmission was achieved by installing an additional filter and changing the frequency function of the chirp signal. There is a restriction on the frequency response of the LPF, which can be realized with a small number of inductors and capacitors, so the frequency function f ðtÞ is determined in accordance with the response of the predesigned LPF. As a result, the frequency function becomes a nonlinear function of t. The pulse compression technique based on a quadrature detector  cannot be applied to a nonlinear chirp signal, so the cross-correlation must be used for the pulse compression. The calculation cost of the cross-correlation is higher than that of the technique using the quadrature detector, but a state-ofthe-art signal processing device will relieve this problem.
ASJC Scopus subject areas
- Acoustics and Ultrasonics