A Low Power Voltage Controlled Oscillator Design

Abstract

The performance of voltage controlled oscillator (VCO) is of great importance for any telecommunication or data transmission network. Here, voltage controlled oscillators (VCOs) using three-transistor NAND gates have been designed. New delay cell with three-transistor NAND gate has been used for designing the ring based VCO circuits. Three-, five-, and seven-stage VCOs have been proposed. Output frequency has been controlled with supply voltage variation from 1.8 V to 2.4 V. Three stage VCO shows output frequency variation in the range of 3.2909 GHz to 4.2280 GHz whereas power consumption varies in the range of 335.4071 W to 486.1816 W. Five-stage VCO depicts frequency in the range of 1.9406 GHz to 2.5769 GHz with power consumption variation from 559.0118 W to 810.3027 W. Moreover a seven-stage VCO shows frequency variation from 1.3984 GHz to 1.8077 GHz. Power consumption of seven-stage VCO varies from 782.6165 W to 1134.400 W. Phase noise results for these VCOs have also been obtained. Power consumption, output frequency, and phase noise results of proposed circuits have been compared with earlier reported circuits, and the proposed circuits show significant improvements.

Properties of Rb CPT Atomic Clock at Subharmonic Microwave Modulation Frequencies

“…Parameters of the studied atomic clocks at different modulation frequencies are summarised in Table 1. Energy consumption of the microwave circuit was calculated in the approximation of its linear dependence upon the RF signal frequency [12], [13]. This approximation was chosen, considering the fact that the RF signal power (<1 mW) is small and amounts to few per cent relative to the total consumption of the microwave train (40-50 mW).…”

“…In both cases, a significant amount of energy consumed by the microwave circuit goes to frequency conversion (either from low to high, or vice versa). The energy consumption may be reduced by lowering the microwave modulation frequency [12], [13]. This approach is also applicable to RF synthesisers based on integrated circuits [14], [15] and consists in reducing the modulation frequency of the injection current from the value of the hyperfine resonance frequency (HRF, 6.835 GHz) down to one of its subharmonics.…”

A Comparative Study of Ring VCO and LC-VCO: Design, Performance Analysis, and Future Trends

“…Thereby, a number of tighter layouts with more delay cells can improve considerable performance [41], [49]. The core building block of a ring VCO is a group of delay cells interconnected in a positive or regenerative feedback loop to create a fundamental ring oscillator [45], [73]. Janet M [42] constructed a ring oscillator with ten inverters, output buffers, and a NAND gate in 1984.…”

Realization of Colpitts Oscillator using second generation current controlled current conveyor

“…The purpose of presenting work is to analyze and exploit the CCCII based current mode oscillator circuit [2][3][4][5][6] which uses only three CCCIIs and two grounded capacitors. The previously introduced concepts were partly reflected and extended, especially in the following points:…”