This book describes the design of low-voltage analog integrated filters using current mirrors, one of the most common building blocks both in analog and mixed-signal VLSI circuits, offering the advantages of low-voltage operation, derivation of resistorless topologies and electronic adjustment capability of their frequency characteristics. Several design examples are described, using current mirrors that fulfill the requirements of modern low-power wireless and biomedical applications, such as universal biquadratic filter topologies, complex filters for Bluetooth/ZigBee low-IF receivers and Wavelet filters for cardiac signal detection. The experimental results from the fabricated chips will also be presented, showing their utility in modern low-voltage low-power portable devices.