A temperature compensated frequency generating system comprising: a crystal oscillator (VCXO) for generating an oscillation frequency; a temperature detection circuit for detecting a temperature and generating a linearly temperature dependent input signal at an output; at least two temperature compensation circuits (204, 206) coupled to the output of the temperature detection circuit for receiving the input signal and generating at least a first group temperature compensation signal and a second group temperature compensation signal according to the input signal, respectively, wherein the at least two temperature compensation circuits (204, 206) comprise a first temperature compensation unit group and a second temperature compensation unit group, the first temperature compensation unit group comprising: a zeroth-order temperature compensation unit coupled to the input signal for outputting a zeroth-order temperature compensation signal; a first-order temperature compensation unit coupled to the input signal for outputting a first-order temperature compensation signal; and a first adder coupled to the zeroth-order temperature compensation signal and the first-order temperature compensation signal for generating the first group temperature compensation signal) not including a second-order temperature compensation component; and the second temperature compensation unit group comprising: an Nth-order temperature compensation unit (2063, 2065) coupled to the input signal for outputting an Nth-order temperature compensation signal (CV3,CV5) being a component of the second group temperature compensation signal consisting of Nth or higher order temperature compensation components, wherein N is greater than 2; and a varactor diode coupled to the at least two temperature compensation circuits (204, 206) to receive the first group temperature compensation signal at an anode terminal and the second group temperature compensation signal at the cathode terminal, the cathode terminal of the varactor diode is connected to an input node of the crystal oscillator (VCXO) for determining the oscillation frequency. a crystal oscillator (VCXO) for generating an oscillation frequency; a temperature detection circuit for detecting a temperature and generating a linearly temperature dependent input signal at an output; at least two temperature compensation circuits (204, 206) coupled to the output of the temperature detection circuit for receiving the input signal and generating at least a first group temperature compensation signal and a second group temperature compensation signal according to the input signal, respectively, wherein the at least two temperature compensation circuits (204, 206) comprise a first temperature compensation unit group and a second temperature compensation unit group, the first temperature compensation unit group comprising: a zeroth-order temperature compensation unit coupled to the input signal for outputting a zeroth-order temperature compensation signal; a first-order temperature compensation unit coupled to the input signal for outputting a first-order temperature compensation signal; and a first adder coupled to the zeroth-order temperature compensation signal and the first-order temperature compensation signal for generating the first group temperature compensation signal) not including a second-order temperature compensation component; and the second temperature compensation unit group comprising: an Nth-order temperature compensation unit (2063, 2065) coupled to the input signal for outputting an Nth-order temperature compensation signal (CV3,CV5) being a component of the second group temperature compensation signal consisting of Nth or higher order temperature compensation components, wherein N is greater than 2; and a zeroth-order temperature compensation unit coupled to the input signal for outputting a zeroth-order temperature compensation signal; a first-order temperature compensation unit coupled to the input signal for outputting a first-order temperature compensation signal; and a first adder coupled to the zeroth-order temperature compensation signal and the first-order temperature compensation signal for generating the first group temperature compensation signal) not including a second-order temperature compensation component; and the second temperature compensation unit group comprising: an Nth-order temperature compensation unit (2063, 2065) coupled to the input signal for outputting an Nth-order temperature compensation signal (CV3,CV5) being a component of the second group temperature compensation signal consisting of Nth or higher order temperature compensation components, wherein N is greater than 2; and a varactor diode coupled to the at least two temperature compensation circuits (204, 206) to receive the first group temperature compensation signal at an anode terminal and the second group temperature compensation signal at the cathode terminal, the cathode terminal of the varactor diode is connected to an input node of the crystal oscillator (VCXO) for determining the oscillation frequency.