Wide Frequency Range Negative Voltage Controlled Oscillator for Automatic Frequency Control

This research paper presents a novel design of Negative Voltage-Controlled Oscillator (NVCO) with a wide frequency range, designed for automatic frequency control (AFC), which covers frequencies from 50 Hz to 2.8 GHz. The NVCO’s block diagram is based on a negative voltage input, which allows for precise frequency tuning within the specified range. This design choice is essential for applications that require fast frequency changes, such as those in frequency-hopping spread spectrum systems or agile communication systems. Moreover, the NVCO can produce output waveforms with a duty cycle ranging from $+\mathbf{5 0 \%}$ to (-) $\mathbf{5 0 \%}$, providing flexibility in waveform generation. The duty cycle, which represents the ratio of time in the high state to the total period, caters to diverse waveform requirements across applications like pulse-width modulation (PWM) and signal conditioning. The NVCO’s specified slew rate, ranging from +5.418 to -5.644 (nns), indicates fast voltage transitions essential for swift frequency changes.