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

A comparative study of different gain cells based microwave CMOS distributed oscillators

“…As the data for DO1 have been reported earlier in Ref. , we will be reporting the results of tunable DVCO1 later in Section 6. The oscillators designed with n‐MOSFET cascode gain cell of Figure (a) are named as DO2 and tunable one as DVCO2.…”

“…We have chosen the 180‐nm standard CMOS process for this comparison, since a fair amount of experimental data are available in the literature for gain cells using this process . The gate resistance has a detrimental effect on the performance of gain cells.…”

“…Traditional non‐TWA oscillators use relatively complex circuits with large on‐chip inductors and capacitors. The use of gain cell between gate and drain lines and 90 Ω coplanar waveguides (CPWs) matched to 50 Ω impedance after FETs loading results in fast rise and fall times , and thus a high oscillation frequency of ∼30 GHz is achieved. Oscillators so designed do not require impedance conversion or buffering.…”

“…Different gain cells have been suggested in literature for DAs and Oscillators (DOs) in different processes. However, there is no proper comparison between DOs using these different gain cells.…”

“…A number of gain cells have been suggested in literature to achieve different desirable characteristics of DAs or distributed oscillators (DOs). Commonly used gain cell are n‐MOSFET , and n‐MOSFETs cascode . We have also proposed n–p MOSFET gain cell earlier in Ref.…”