This classic was the first to fill the need for an undergraduate text in analog filters for electrical engineering. Intended for juniors and seniors with a background in introductory circuits, including Laplace transforms, the text focuses on inductorless filters in which the active element is the operational amplifier (op-amp). Passive LCR filters are excluded except as prototypes from which an active equivalent is then found. Students learn the importance of op-amps to analog systems, which Van Valkenburg equates with the significance of the microprocessor to digital systems. Because the book is intended for undergraduates, sophisticated mathematics has been avoided wherever possible in favor of algebraic derivations. Design topics require at most a hand-held calculator.