Electronically Tunable Quadrature Sinusoidal Oscillator with Equal Output Amplitudes during Frequency Tuning Process

Abstract

A new configuration of voltage-mode quadrature sinusoidal oscillator is proposed. The proposed oscillator employs two voltage differencing current conveyors (VDCCs), two resistors, and two grounded capacitors. In this design, the use of multiple/dual output terminal active building block is not required. The tuning of frequency of oscillation (FO) can be done electronically by adjusting the bias current of active device without affecting condition of oscillation (CO). The electronic tuning can be done by controlling the bias current using a digital circuit. The amplitude of two sinusoidal outputs is equal when the frequency of oscillation is tuned. This makes the sinusoidal output voltages meet good total harmonic distortions (THD). Moreover, the proposed circuit can provide the sinusoidal output current with high impedance which is connected to external load or to another circuit without the use of buffer device. To confirm that the oscillator can generate the quadrature sinusoidal output signal, the experimental results using VDCC constructed from commercially available ICs are also included. The experimental results agree well with theoretical anticipation.

Various applications of analog signal processing employing voltage differencing current conveyor and only grounded passive elements: a re-convertible approach

“…(1) by employing LM13700 and AD844 [31] (2) possibly using CA3080 and AD844 (3) utilizing OPA860 only. OPA860 is commonly known as diamond transistor or special purpose amplifier [37].…”

“…The design solutions for analog signal processing applications by employing different active building blocks such as the realization of a synthetic inductor [3][4][5][6][7][8], formation of active filters [9][10][11][12][13][14][15][16][17][18][19][20][21], and generation of sinusoidal oscillators [19,[21][22][23][24][25][26][27][28][29][30][31][32][33] are available in the open literature. Inductors can be further classified as grounded [3][4][5][6][7] and ungrounded or floating inductors [6,8].…”

Single VDCC-Based Electronically Tunable Voltage-Mode Second Order Universal Filter

“…Literature review shows that, a number of the analog circuits using VDCC as active element have been found for examples, inductance simulator [10][11], capacitance multiplier [12][13], versatile passive element simulator [14][15], square and triangular wave generator [16], sinusoidal oscillator [6,13,[17][18][19][20], first order allpass filter [21], ladder filter [22] etc. The VDCC based universal filters have been proposed in [23][24][25][26].…”