Circuit for generating two closely adjacent frequencies
AssigneeSiemens Aktiengesellschaft
InventorManfred Ley
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Abstract
A circuit for generating two closely adjacent frequencies includes two oscillators each generating one of two closely adjacent frequencies. A PLL circuit is connected to the oscillators for regulating the frequencies. The PLL circuit performs a frequency comparison of the frequency generated by only one of the oscillators with a reference frequency to generate a frequency comparison output signal of the PLL circuit, and it regulates the frequencies of both of the oscillators as a function of the frequency comparison output signal of the PLL circuit.
Claims3
Circuit for generating two closely adjacent frequencies, comprising two oscillators each generating one of two closely adjacent frequencies, and a PLL circuit connected to said oscillators for regulating the frequencies, said PLL circuit including means for performing a frequency comparison of the frequency generated by only one of said oscillators with a reference frequency to generate a frequency comparison output signal of said PLL circuit, and for regulating the frequencies of both of said oscillators as a function of the frequency comparison output signal of said PLL circuit;
- wherein said oscillators are ring oscillators formed by ECL inverters;
- including means for defining the frequencies of said ring oscillators formed by ECL inverters with a dissimilar value of a frequency-determining magnitude, and means for regulating the frequencies by adjusting the value of the frequency-determining magnitude through the frequency comparison output signal of the PLL circuit.
Dependencies are inferred from the claim text.