Abstract
An electronically controllable fully uncoupled explicit current-mode quadrature oscillator employing Voltage Differencing Transconductance Amplifiers (VDTAs) as active elements has been presented. The proposed configuration employs two VDTAs along with grounded capacitors and offers the following advantageous features 1) fully and electronically independent control of condition of oscillation (CO) and frequency of oscillation (FO); 2) explicit current-mode quadrature oscillations; and 3) low active and passive sensitivities. The workability of proposed configuration has been demonstrated by PSPICE simulations with TSMC CMOS 0.18 μm process parameters.
Highlights
Among various kinds of oscillators, the quadrature oscillators (QO) are widely used because they can provide two sinusoids with π/2 phase difference, for example, in telecommunication systems, for quadrature mixtures and single-sideband generators or for measurement purposes in vector generators or selective voltmeters [1,2]
By considering the various VDTA non-ideal parameters like the finite P-terminal parasitic impedance consisting of a resistance RP in parallel with capacitance CP, the finite N-terminal parasitic impedance consisting of a resistance RN in parallel with capacitance CN, the finite X-terminal parasitic impedance consisting of a resistance
Power supply voltages were taken as VDD = −VSS = 0.9 V and IB1 = IB2 = IB3 = IB4 = 2 mA and IB1 = IB2 = 2 mA, IB3 = IB4 = 3.687 mA biasing currents are used
Summary
Among various kinds of oscillators, the quadrature oscillators (QO) are widely used because they can provide two sinusoids with π/2 phase difference, for example, in telecommunication systems, for quadrature mixtures and single-sideband generators or for measurement purposes in vector generators or selective voltmeters [1,2]. A CMOS realization of VDTA and its applications as 1) RF filter and 2) double tuned amplifier have been presented in [12]. In [13], an electronically controllable explicit current-output sinusoidal oscillator has been reported. Another application as a single input five output voltage-mode universal filter using VDTAs has been presented in [14]. The purpose of this communication is to introduce a new electronically controllable fully uncoupled explicit current-mode quadrature oscillator using two VDTAs and two grounded capacitors. The workability of proposed configuration has been verified using SPICE simulation with TSMC CMOS 0.18 μm process parameters
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
