Patent ID: 8289094
Filing Date: 2012-10-16
Classification: H03B,H03L

Abstract:
1. A voltage controlled oscillator circuit comprising: a VCO resonator circuit having a first plurality of varactors for varying a frequency of said VCO resonator circuit, said VCO resonator circuit being symmetrical with respect to VCO circuit ground and providing a signal having a frequency, said frequency depending on a tuning voltage applied to said first plurality of varactors, and a second plurality of varactors for compensating a drift of said frequency depending on a compensation voltage, said second plurality of varactors receiving said compensation voltage from a low pass filter; a temperature sensor circuit sensing an ambient temperature of said VCO resonator circuit and providing a temperature dependent signal; and a temperature compensation circuit providing said compensation voltage depending on said temperature dependent signal, wherein said temperature compensation circuit comprises at least one operational amplifier and said compensation voltage is provided to said low pass filter, wherein said temperature compensation circuit has a programmable gain and comprises at least one multiplying digital-to-analog converter (MDAC), the multiplying digital-to-analog converter (MDAC) is connected in a feedback path of a second operational amplifier circuit.