Novel Minimum Component Dual Mode Biquadratic SIMO Filter with Electronic Tunability

Abstract

Two topologies of minimum component single input multiple output (SIMO) filters are designed by employing a versatile active building block (ABB), the current conveyor transconductance amplifier (CCTA). The proposed filters work in current mode (CM) and trans-admittance mode (TAM). The CM SIMO filter is designed using two CCTA and two grounded capacitors. The CM filter can be converted to TAM filter just by adding a grounded resistor without any change in the topology. There is no need of passive component matching, and the filters provide all the five responses namely, high-pass (HP), band-pass (BP), low-pass (LP), all-pass (AP), and band-stop (BS) simultaneously. In addition, it provides an independent electronic tunability of angular frequency (ω) and quality factor (Q). The active and passive sensitivities of the filter parameters are low. In CM mode the filter offers low input impedances and high output impedances and in TAM mode the filter offers high input impedance and hight output impedance that support the cascadeability. The CM and TAM filters are designed for a frequency 16.23MHz and the simulation results employing 0.18 µm CMOS technology parameters at a supply voltage of ±1.25 V are obtained using Cadence software to validate the proposed design. Also, the proposed CM SIMO universal filter has been implemented in hardware to confirm its practicality. The commercially available integrated circuits (ICs), the current feedback operational amplifier (AD844) and operational transconductance amplifier (CA3080) and employed for the experimental validation.