High-Resolution Millimeter-Wave Digitally Controlled Oscillators With Recon figur

Abstract

Two new millimeter-wave digitally controlled oscillators (DCOs) that achieve a tuning range 10% and fine frequency resolution 1 MHz simultaneously are described. Switched metal capacitors distributed across a passive resonator tune the oscillation frequency. To obtain sub-MHz frequency resolution, tuning step attenuation techniques exploiting an inductor and a transformer are proposed. Two 60-GHz imple- mentations, a fine-resolution inductor-based DCO (L-DCO) and a transformer-coupled DCO (T-D CO)