An Explicit Output Current-mode Quadrature Sinusoidal Oscillator and a Universal Filter Employing Only Grounded Passive Components - a Minimal Realisation

Single VDGA-Based Mixed-Mode Universal Filter and Dual-Mode Quadrature Oscillator

“…Even though compact MUBF circuits implemented with a single active element have been proposed in [ 3 , 8 , 16 , 21 , 24 , 27 , 28 , 41 , 48 ], these biquads still use more passive elements than the MUBF circuit proposed in this work. While the designs described in [ 4 , 7 , 12 , 14 , 15 , 18 , 19 , 20 , 23 , 26 , 45 , 49 , 50 ] are interesting, they suffer from the usage of two or more different types of active components, which complicates circuit implementation.…”

“…Note that the above-mentioned realizations only work with the mixed-mode universal biquad filter or the QO circuit. Interestingly, [ 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 ] suggest circuit realizations that can perform both universal biquad filter and QO with the same circuit design. A comparison of available related works is made in Table 1 .…”

“…A comparison of available related works is made in Table 1 . A thorough examination of Table 1 shows that the MUBF realizations in [ 2 , 6 , 8 , 11 , 16 , 19 , 20 , 24 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 ] were unable to realize the various filter functions in all four possible operation modes, including voltage-mode (VM), current-mode (CM), trans-admittance-mode (TAM), and trans-impedance-mode (TIM). Furthermore, the QOs in [ 44 , 47 , 49 ] only generated voltage-mode quadrature signals, while those in [ 42 , 43 ] generated current-mode quadrature signals.…”

“…However, little effort has been made on the design of DMQO [ 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 ]. The realizations in [ 1 , 2 , 4 , 5 , 6 , 7 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 17 , 18 , 19 , 20 , 22 , 23 , 25 , 26 , 29 , 30 , 31 , 33 , 34 , 37 , 39 , 42 , 43 , 44 , 45 , 46 , 47 , 49 , 50 ] need two or more active components. Four or more passive components were used in the circuits described in [ 2 , 3 , 4 , 6 , 8 , 9 , 12 , 13 , 14 , 15 , 16 , …”

“…Moreover, the inbuilt tunability feature is not provided for the approaches presented in [ 2 , 3 , 4 , 6 , 8 , 9 , 12 , 13 , 19 , 22 , 23 , 31 , 32 , 34 , 39 , 47 ]. The circuits in [ 2 , 6 , 7 , 8 , 10 , 13 , 18 , 21 , 23 , 28 , 31 , 40 , 42 , 43 , 48 , 50 ] also do not allow for independent tuning of the important characteristics, such as the natural angular frequency and quality factor for MUBF, or the oscillation condition and frequency for QO.…”