Abstract: An integrated circuit design for differential variable capacitors uses an integration method to integrate an integrated circuit having differential variable capacitors as a whole, and takes the parasitic effect into consideration for the manufacturing process to lower the circuit inaccuracy and reduce the chip size effectively. Such arrangement lowers the manufacturing cost, identifies the quality of loading quality of the overall variable capacitance during the manufacture, and further controls the quality of loading capacity of the overall variable capacitance effectively. Furthermore, this invention does not need to reposition for the symmetrical position of the coils, and thus giving a very precise positioning to reduce the level of difficulty for the manufacture.

Abstract: Improved voltage controlled oscillator (VCO) circuits are disclosed. A symmetrical voltage controlled oscillator (VCO) system according to the embodiments of the present invention comprises a frequency tuning circuit containing one or more varactors for receiving a predetermined tuning signal and a frequency tuning bias signal for altering capacitances of the varactors, a modulation circuit coupled in parallel with the frequency tuning circuit containing one or more varactors for modulating one or more outputs, and a core circuit coupled in a parallel with the tuning circuit and the modulation circuit for providing an oscillation mechanism, wherein the core circuit has an inductance module coupled in a parallel fashion with the frequency tuning circuit and the modulation circuit, wherein circuit elements of the VCO system are symmetrically arranged for increasing oscillation efficiency thereof and the varactors are tuned to deliver the output at an output frequency.

Abstract: A system is provided to improve frequency stability and system linearity in voltage controlled oscillators.

Abstract: An integrated circuit design for differential variable capacitors uses an integration method to integrate an integrated circuit having differential variable capacitors as a whole, and takes the parasitic effect into consideration for the manufacturing process to lower the circuit inaccuracy and reduce the chip size effectively. Such arrangement lowers the manufacturing cost, identifies the quality of loading quality of the overall variable capacitance during the manufacture, and further controls the quality of loading capacity of the overall variable capacitance effectively. Furthermore, this invention does not need to reposition for the symmetrical position of the coils, and thus giving a very precise positioning to reduce the level of difficulty for the manufacture.

Abstract: A VCO system embodying the features of the present invention includes a frequency tuning circuit, a modulation circuit coupled in a parallel fashion with the frequency tuning circuit, a band tuning circuit coupled with the frequency tuning circuit in a parallel fashion having at least one switching circuit, a core circuit coupled with the frequency tuning circuit, the modulation circuit, and the band tuning circuit, wherein upon asserting a switching signal and upon adjusting a frequency turning signal, a frequency tuning bias signal, and a band tuning signal, the switching circuit is enabled for configuring the band tuning circuit to join the frequency tuning circuit for adjusting a predetermined output frequency based on a total inductance and a total capacitance provided by the core circuit, the frequency tuning circuit, the modulation circuit and the band tuning circuit.

Abstract: A system is provided to improve frequency stability and system linearity in voltage controlled oscillators.

Abstract: Improved voltage controlled oscillator (VCO) circuits are disclosed. A symmetrical voltage controlled oscillator (VCO) system according to the embodiments of the present invention comprises a frequency tuning circuit containing one or more varactors for receiving a predetermined tuning signal and a frequency tuning bias signal for altering capacitances of the varactors, a modulation circuit coupled in parallel with the frequency tuning circuit containing one or more varactors for modulating one or more outputs, and a core circuit coupled in a parallel with the tuning circuit and the modulation circuit for providing an oscillation mechanism, wherein the core circuit has an inductance module coupled in a parallel fashion with the frequency tuning circuit and the modulation circuit, wherein circuit elements of the VCO system are symmetrically arranged for increasing oscillation efficiency thereof and the varactors are tuned to deliver the output at an output frequency.

Abstract: A VCO system embodying the features of the present invention includes a frequency tuning circuit, a modulation circuit coupled in a parallel fashion with the frequency tuning circuit, a band tuning circuit coupled with the frequency tuning circuit in a parallel fashion having at least one switching circuit, a core circuit coupled with the frequency tuning circuit, the modulation circuit, and the band tuning circuit, wherein upon asserting a switching signal and upon adjusting a frequency turning signal, a frequency tuning bias signal, and a band tuning signal, the switching circuit is enabled for configuring the band tuning circuit to join the frequency tuning circuit for adjusting a predetermined output frequency based on a total inductance and a total capacitance provided by the core circuit, the frequency tuning circuit, the modulation circuit and the band tuning circuit.