A Multi-Frequency MEMS-Based RF Oscillator Covering the Range from 11.7MHz to 1.9GHz
Due to the increasing number of mobile-communication standards in wireless devices, the need for oscillators generating more than one frequency is rising. Especially in the radio-frequency domain, micro-electromechanical systems (MEMS)-based oscillators are advantageous hardware components because of their small size, excellent phase-noise performance and low power consumption. To reach oscillation frequencies above 1GHz, and to change the frequency of oscillation, dedicated circuit topologies are required. In this paper, the design, fabrication, and measurement of a multi-frequency MEMS oscillator employing two different MEMS resonators and covering the frequency range from 11.7MHz to 1.9GHz is described. By using an application-specific integrated circuit, the scope of functions can be increased without changing the module size, e.g., by an integrated frequency doubler to raise the upper frequency limit provided by the MEMS-resonator technology. As a result, the highest oscillation frequency could be achieved with good phase-noise performance as compared to the state-of-the-art.