## 1 Introduction  
A quadrature sinusoidal oscillator is a very important active element for communication, instrumentation, and measurement systems, and can be employed in a quadrature mixer and a single-sideband modulator of telecommunications [1; 2]. In communication systems, a sinusoidal oscillator can generate an amplitude-controllable sinusoidal signal, which can be used to apply the carrier signal for amplitude modulation (AM) and amplitude shift keying (ASK) signal systems [3]. Recently, current conveyors are receiving considerable attention due to their potential advantages, such as inherently wide bandwidth, high slew-rate, good linearity, wide dynamic range, simple circuitry, and low power consumption [4]. This interesting active element, based on second-generation current conveyor transconductance amplifiers (CCIITA) [5], has been introduced to provide new possibilities in the realization of a class of analog signal processing circuits. This CCIITA can provide flexibility in operating both current and voltage modes, and can enable a variety of circuit designs and provides electronic tuning ability through its transconductance gain, \(g_{m}\). However, the CCIITA cannot control the parasitic resistance, \(R_{\mathrm{X}}\), at \(X\) port. Hence, when the CCIITA is used in some circuits, it must unavoidably require some external passive components, especially with the resistors. In contrast, the introduced current-controlled current conveyor transconductance amplifier (CCCCTA) [5; 6] has two electronically adjustable ports, whereas the CCIITA has only one electronically adjustable port. The parasitic resistance, \(R_{\mathrm{X}}\), at current input port of the CCCCTA can be adjusted by an input bias current, which does not require a resistor in practical applications. Intuitively, the CCCCTA is a versatile active building block, which provides the possibility of utilizing its transconductance gain, \(g_{m}\), and its equivalent input resistance, namely parasitic resistance, \(R_{\mathrm{X}}\), to create a resistorless oscillator scheme. The multiple current output terminals of the CCCCTA can be easily obtained by adding additional current mirrors at these output terminals. Electronically tunable active components are receiving more attention as traditional electronic components may have deviations in fine-tuning the tolerances of the electronic components [7]. The electronically tunable active components of the previous second-order oscillators include second generation current controlled conveyors (CCCIIs) [8; 9]; operational transconductance amplifiers (OTAs) [10]; current differencing buffered amplifiers (CDBAs) [11; 12]; the CCIITA [13]; current differencing transconductance amplifiers (CDTAs) [14; 15; 16; 17; 18; 19]; multiple-output current controlled current conveyor transconductance amplifiers (MO-CCCATAs) [20]; and voltage differencing transconductance amplifiers (VDTAs) [21]. These circuits were used to design the second-order quadrature current outputs, quadrature voltage outputs, or both quadrature current and voltage outputs. In addition to all of the above second-order quadrature oscillators, several third-order quadrature oscillators have also been proposed [22; 23; 24; 25; 26; 27; 28; 29; 30; 31; 32]. The third-order oscillators have higher accuracy, higher quality factor, and lower harmonic distortion than the second-order oscillators [22; 23]. However, the third-order oscillator in Figure 7 of Reference [22] uses three OTAs and three grounded capacitors. The third-order oscillator in Reference [23] uses four multiple-output second-generation current-controlled conveyors (MO-CCIIs) and three grounded capacitors. The third-order oscillator in Figure 1 of Reference [24] uses three second-generation current conveyors (CCIIs), five grounded resistors and three capacitors. The third-order oscillator in Reference [25] uses two MO-CCCATAs and three grounded capacitors.