摘要 |
<p>A topology for a high speed voltage controlled oscillator (VCO) with quadrature outputs is produced utilizing four inverting differential circuits (12, 14, 16, 18). The fully differential four stage ring oscillator has outputs from alternate delay circuits combined in balanced exclusive OR gate frequency doublers (24, 26) to provide both in-phase and quadrature output signals at twice the ring oscillator frequency. The period of the quadrature delay signals is four gate delays and is easily realized in the Ghz frequency ranges. The in-phase and quadrature output signals are again combined in a balanced exclusive OR gate frequency doubler (36) to obtain a final output frequency quadruple the ring oscillator frequency.</p> |