Chapter 15
Design and Optimization of Integrated Transmission Lines on Scaled CMOS Technologies
15.1 Introduction
In mm-wave on-chip applications, integrated transmission lines are mandatory to interconnect different blocks of the RF chip (e.g., LNAs, local oscillators, mixers, and PAs). They are also attractive to implement on-chip functions such as matching sections, filters, and baluns, which would require inductive components with very small values, typically in the range of 30–300 pH. Though in this scenario spiral inductors could result in small area occupation, their value can be predicted with poor accuracy. When many inductors connect to the same active device, not only the distribution network adds significant contribution to each spiral impedance but also mutual effects, hard to be accurately predicted, become a significant source of error, especially when dealing with low inductors' values.
Short-circuited line sections can effectively replace inductors at these frequencies, bringing some practical advantages. ...
