Voltage-tunable immittance functions: Linear voltage-controlled quadrature oscillator implementation. Issue 1 (2nd January 2023)

• Record Type: Journal Article
• Authors: Mathur, K.; Nandi, R.
• Is Part Of: International journal of electronics letters. Volume 11:Issue 1(2023)
• Page Start: 68
• Page End: 79
• Publication Date: 2023-01-02
• Subjects: CFA -- synthetic inductor/FDNR -- bandpass filter -- band-reject filter -- quadrature -- phase-noise -- linear VCO; Electronics -- Periodicals; Electronics; Periodicals; 621.38105
• DOI: 10.1080/21681724.2021.2025441
• Languages: English
• ISSNs: 2168-1732

Abstract

ABSTRACT: A new scheme on the realisation of voltage-tunable immittance function (VTIF) is proposed. Here two types of grounded, high-quality (Q) resonant filters and voltage-controlled quadrature oscillators (VCQO) with a linear tuning law are presented. Analysis indicates that the filter/QO parameters are impervious to the ABB parasitic components. Experimental results exhibit a VCQO-linear tuning range of fo ~14 MHz with a satisfactory phase-noise margin of immittances, viz., inductance (L) and frequency-dependent negative resistance (D) are derived using the Current Feedback Amplifier (CFA) combined with analog voltage-multiplier elements as the active building block (ABB). Subsequently, implementation of LC-bandpass and rD-band-reject selective filters, along with QO designs, is presented with low THD and phase noise of (─)104 dBc/Hz at 30 kHz offset. Experimental results of the proposed circuits had been satisfactorily verified using standard commercially available IC modules.