Novel Electronically Tunable Biquadratic Mixed- Mode Universal Filter Capable of Operating in MISO and SIMO Configurations

Abstract

In this paper, a novel electronically tunable biquadratic universal mixed-mode filter is presented. The filter is based on extra X current conveyor transconductance amplifier (EXCCTA), recently introduced by authors. The proposed filter employs two EXCCTAs, two capacitors, a switch, and four resistors. The filter can work in both multi-input-single-output (MISO) and single-input-multi-output (SIMO) configurations without change in its structure. The filter provides low-pass (LP), high-pass (HP), band-pass (BP), band-reject (BR) and all-pass (AP) responses in voltage-mode (VM), current-mode (CM), transimpedance-mode (TIM), and transadmittance-mode (TAM). The attractive features of the filter include (i) ability to operate in both MISO and SIMO configurations in all four modes, (ii) no requirement of capacitive matching, (iii) high output impedance in SIMO (CM & TAM) configuration, (iv) tunability of quality factor ( Q ) independent of natural frequency ( ) in MISO & SIMO configurations, (v) use of grounded capacitors in SIMO configuration, (vi) low output impedance for MISO (VM & TIM), (vii) high output impedance explicit current output for MISO (CM & TAM), and (viii) no requirement for double/negative input signals (voltage/current) in MISO configuration. The non-ideal gain and sensitivity analysis is also carried out to study the effects of process variations and passive components spread on filter performance. The filter is designed in Cadence Virtuoso using Silterra Malaysia 0.18µm PDK. The complete layout of the EXCCTA is designed and the parasitic extraction is done. The filter is tested at a supply voltage of ±1.25 V and the obtained results validate the theoretical findings.