Temperature Characteristics and Analysis of Monolithic Microwave CMOS Distributed Oscillators With ${G}_{m}$-Varied Gain Cells and Folded Coplanar Interconnects

The performance of a novel Monolithic Microwave CMOS Distributed Oscillator is reported over a temperature range of -25
^°
C to 75
^°
C for the first time, along with an analysis of its design characteristics and its temperature stability. The oscillator is stable over the entire temperature range of 100
^°
C. The monolithic distributed oscillator (DO) is designed and fabricated in an industry standard 0.18 μ m CMOS process, using an n-FET-based traveling wave amplifier (TWA), coplanar waveguides (CPW), and a new coplanar interconnect structure called a 'folded CPW'. The measured loss of the “folded CPW” is 1.259 dB at 10 GHz. The distributed oscillator uses a novel architecture of
Gm
-varied gain cells and operates at a bias of 1.8 V. The measured oscillation frequency is 11.7 GHz with 6.1 dBm output power and the measured phase noise is -116.02 dBc/Hz at 1 MHz offset, which represent the best reported power and one of the best phase noise results for silicon DOs with temperature stability.