Patent ID: 8093958
Filing Date: 2012-01-10
Classification: H03B,H03L

Abstract:
1. An apparatus to generate a harmonic reference signal, the apparatus comprising: a reference resonator configured to generate a first reference signal having a resonant frequency, said reference resonator comprising an LC tank circuit configured to generate the first reference signal at a differential output thereof; a frequency controller coupled to the reference resonator, the frequency controller configured to maintain substantially constant a peak amplitude of the first reference signal or a common mode voltage level of the reference resonator; a plurality of reactance modules coupled to the reference resonator, each reactance module of the plurality of reactance modules comprising one or more reactance unit cells, and each reactance until cell comprising a reactance element coupled in series to a switching element; and a temperature-responsive frequency compensation module electrically coupled to the differential output of said LC tank circuit, said temperature-responsive frequency compensation module comprising first and second arrays of switchable capacitive modules electrically coupled to first and second nodes of the differential output of said LC tank circuit, respectively, and a temperature-dependent control voltage generator configured to provide a temperature-dependent control voltage, said control voltage generator comprising at least one current source configured to generate a temperature-dependent current, an amplifier and a variable resistor electrically coupled to the at least one current source, said variable resistor comprising a bank of resistors that are connected between an input and output of the amplifier and are switched in and out of said control voltage generator in response to a plurality of first control coefficients.