Comments on "bandpass sigma-delta modulator employing saw resonator as loop filter"

Some corrections needed in the theoretical analysis of the surface acoustic wave resonator loop filter for a bandpass sigma-delta modulator, as presented by Yu and Xu, are pointed out. A simple idea is also proposed for perfect cancellation of anti-resonance without substantially affecting the resonance frequency, but with the added benefits of an enhanced factor and insertion gain, rather than insertion loss. However, a practical implementation of the idea remains an open question

Authors' Reply to "Comments on bandpass sigma-delta modulator employing SAW resonator as loop filter"

10.1109/TCSI.2008.918266IEEE Transactions on Circuits and Systems I: Regular Papers5572152