Tunable frequency CMOS OTA-C sinusoidal oscillators for high frequency applications

This paper presents the realization of different sinusoidal oscillators employing operational transconductance amplifiers (OTAs). CMOS OTA-C sinusoidal oscillators are designed using 0.18 µm SCL technology library in Cadence Virtuoso tool. The oscillator circuit topologies which employ a minimum number of OTAs (three to five) along with a minimum number of capacitors (two) with capacitors being grounded are designed and the frequency of oscillations are compared with the theoretical values. Tunable frequency OTA-C oscillators exhibit the oscillation frequency in the range of 90 MHz to 190 MHz by varying the transconductance of OTA with a supply voltage of ±0.9 V and 6 GHz unity gain bandwidth single ended OTA.