CCII based more tunable voltage-mode all-pass filters and their quadrature oscillator applications

In this paper, two new voltage-mode (VM) first-order all-pass filters using single active element namely second-generation current conveyor (CCII) and a grounding capacitor are proposed. The first proposed filter employs a dual output CCII (DO-CCII) and the other one uses a modified minus type CCII (MCCII−). One of the main advantages of both configurations is their high input impedances; thus, both can be easily cascaded with other VM circuits. Additionally, the use of a grounded capacitor in both circuits provides suitability for integrated circuit (IC) fabrication process. However, both of the proposed circuits need a single passive component matching constraint. Non-ideality analysis is performed for the proposed circuits. Moreover, two quadrature oscillator applications of the proposed filters are given. The behavior of the filters is verified by SPICE simulations. Also, experimental tests using commercially available ICs (AD844s) are achieved for the second proposed configuration.