A surface-mounted RF IC technology demonstrated with a 10 GHz LC oscillator with copper coils

A surface-mounted RF IC fabrication technology is presented that includes a substrate transfer processing step to glass. The fabrication technology uses copper in one of the last fabrication steps to form contacts and inductors. To demonstrate the technology, a differential varactorless 10 GHz LC oscillator is fabricated. The quality factor of the used 0.63 nH inductor is estimated by measuring the required start-up current of the oscillator. With a supply voltage of 3 V, the estimated quality factor is as high as 39 at 10 GHz. At 10 GHz the dissipation of the oscillator core is 0.42 mW (with 3 V supply voltage) and the measured phase noise better than -94.7 dBc/Hz at 1 MHz offset of the carrier. By increasing the bias current, the frequency can be tuned from 10.2 GHz to 8.7 GHz, which corresponds to a 15.8% tuning range. The proposed fabrication technology eliminates bond-wires, reduces cross-talk and yields excellent passives.