Transformer feedback millimeter-wave VCO with capacitance cancellation technique in 0.18-.MU.m CMOS

Abstract

This paper describes a design procedure for mm-wave voltage controlled oscillator (VCO), based on large signal behavior of oscillator transconductance. Then, a new structure of LC-VCO is presented, which utilizes a transformer feedback to enhance the transconductance of the core transistors and to cancel the undesired parasitic effects. Using a 0.18-μm RF CMOS technology, the advantage of this VCO is examined by large signal analysis and simulation. The results illustrate improvement of 5 dB in phase-noise and 70% in tuning-range, compared to enhanced active gain conventional transformer feedback VCO. Finally, a compact layout for transformer design is proposed.

Characterization and modeling of on-chip via stacks for RF-CMOS applications

“…The circuit model presents a maximum average error of 5.1% for the return loss (i.e., jS 11 j) when compared with experimental data. Furthermore, with the purpose of measuring the impact of these inter-metallic elements in the performance of RF applications [16,17,18,19,20,21], the via stack circuit model is applied here for representing a RTWO. The importance of this particular application example relies on the fact that this type of oscillators allow fulfilling the design requirements for high frequencies applications (i.e.…”