High-frequency log-domain current-mode multiphase sinusoidal oscillator

Abstract

This study describes the design of a multiphase sinusoidal oscillator (MSO) based on log-domain filtering concept. The circuit is a direct realisation of a first-order differential equation for obtaining the inverting and non-inverting low-pass filters. Each low-pass filter comprises only a grounded capacitor and four transistors. The proposed MSO can be instantaneously controlled over a very wide frequency range by controlling the current for the oscillation frequency and oscillation condition which indicates the proposed MSO's suitability in high-frequency applications. A validated bipolar junction transistor (BJT) model is used in SPICE simulation operated from a single power supply as low as 2.5 V. The oscillation frequency is controlled over four decades of frequency. The total harmonic distortions for three phase (11.5 MHz) and four phase (7 MHz) are, respectively, obtained around 2.4 and 2.2% which enables them to be fully integrated in telecommunication systems. The power consumption is around 5.5 mW for 100 mA bias current. Moreover, experimental results of three-phase MSO are included. 440

A wideband linear tunable CDTA and its application in field programmable analogue array

“…28 Fig. 37 is main due to the 2nd and 3nd harmonic frequency components of multi-phase oscillators [48][49][50].…”

On the Realization of Multiphase Oscillators Using Fractional-Order Allpass Filters

“…Resistor r was set at 1 k . Note that the desired oscillation frequency was deliberately set to f o , which according to (16) requires R = 1.591 k . This procedure was then repeated for the remaining cases, and the results are tabulated in Table 2(a) along with the observed oscillation frequency f o from PSPICE.…”

“…(17) If leading phase circuits are used instead, we choose φ = 0 • , which implies that a noninverting amplifier can be used with (16) and (17) being equally valid for this case. From (16) it is clear that high frequencies, higher than those obtained by the classical expression ω o = 1/τ , are possible for α < 1. Possible realizations using the circuits of Fig.…”

Active-only variable-gain low-pass filter for dual-mode multiphase sinusoidal oscillator application

“…In [13], an active-only oscillator circuit using OA and OTA was realized to achieve the FO-CO independency. In addition, a multiphase oscillator was deployed in the phase modulator [14] and vector signal generator [15]. The cascading of all-pass filters with an integrator [16] and two lossless integrators [17] in the absence of the passive elements was implemented for the quadrature sinusoidal oscillators (QSOs).…”