A New Dual-Frequency LC Oscillator: Analysis and Design

In this paper, a new dual-frequency LC oscillator is introduced. This new architecture is designed taking the advantage of a Wheatstone-bridge LC resonator concept that enables the oscillator to generate two different frequencies simultaneously. In contrast to the previous designs, no transistor switches are incorporated in the structure of this dual-frequency circuit. So, the proposed configuration is suitable for the low phase noise applications. The performance of the oscillator has been verified using circuit simulations in 0.18 µm CMOS technology. Circuit simulations show the phase noises of -109 dBc/Hz, -105 dBc/Hz for 1.8 GHz and 2.7 GHz frequency bands respectively in 100 kHz offset frequency.