To demonstrate feasibility of millimetre-wave Voltage Controlled Oscillators (VCOS) based on high Q-factor resonator

 

Local oscillators (LO) used in microwave and millimetre-wave radiometer receivers for Earth Observation (EO) are normally based on Dielectric Resonator Oscillators (DRO) that are limited to a typical frequency of about 30 GHz. The LO frequency in the millimetre-wave range (165.4 to 229 GHz) is then obtained by means of additional multiplier circuits and band-pass filters, thus increasing the complexity of the circuit, mass and power consumption, and reducing reliability. Additionally, multiplication increases phase noise on the output, which affects coherent systems such as synthetic aperture interferometric radiometers.

 

For the reference signal to be generated at a higher frequency a high Q-factor resonator is needed, operating at several GHz. Preliminary assessment of oscillators using ultra-high Q-factor silicon resonators, demonstrate power consumption reduction of about 40%, and volume mass reduction of around 50%. This would allow better integration of the receivers behind the antenna radiating elements.

 

This activity encompasses the following tasks:

- Review promising high frequency resonator technologies

- design, manufacture and tested resonators- Produce high performance oscillator based on such resonators, without frequency stabilization by an external low-frequency crystal reference, operating directly at millimetre-wave ghz range.

-Assess feasibility of the achieved performance for high frequency LO signal generation