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This work presents the design of a 24-GHz digitally controlled oscillator (DCO) in an advanced 28-nm bulk CMOS technology for short-range frequency-modulated continuous-wave radar system-on-chip for mobile and Internet-of-Things devices. The power minimization is therefore the primary focus. The oscillator consumes a record low power of 1.2 mW at a 0.65-V supply voltage. It achieves a very large frequency tuning range (TR) of 5.8 GHz (27%) and a 150 kHz resolution without significantly degrading the phase noise (PN). The proposed design methodology results in a state-of-the-art -193 dBc/Hz FoM(T).

This paper presents an analysis of different mod­ulations that can be used at low-IF in short-range frequency- modulated continuous wave (FMCW) radars which are more sensitive to DC offsets and flicker noise. These modulations are also a key functionality in multiple-input multiple-output (MIMO) FMCW radars to implement orthogonality between the different transmit signals. Architectures with two PLLs, set at slightly different frequencies to create a low-IF, and one PLL, using OOK and BPSK modulations, are compared regarding their phase noise at the resulting IF signal. Measurements were performed on a COTS 60 GHz FMCW radar to validate the calculated and simulated results.

This paper presents a study of MOSFETs’ linearity, exploiting a simplified version of the charge-based EKV model. It allows to deduce analytically the one-tone and two-tone harmonic distortions introduced by the nonlinear $I_{D}$ – $V_{G}$ MOSFET characteristic as a function of the inversion coefficient. The short-channel effects are included in order to address nanoscale MOSFET performance. The analysis is validated through comparisons with the BSIM6 model and measurement results from 28-nm bulk CMOS devices. By means of this model, the designer can choose the appropriate bias region for the critical devices of a circuit depending on the system requirements.

This article presents the s implified charge-based Enz-Krummenacher-Vittoz (EKV) [11] metal-oxide-semiconductor field-effect transistor (MOSFET) model and shows that it can be used for advanced complementary metal-oxide-semiconductor (CMOS) processes despite its very few parameters. The concept of an inversion coefficient (IC) is first introduced as an essential design parameter that replaces the overdrive voltage VG-VT0 and spans the entire range of operating points from weak via moderate to strong inversion (SI), including the effect of velocity saturation (VS). The simplified model in saturation is then presented and validated for different 40- and 28-nm bulk CMOS processes. A very simple expression of the normalized transconductance in saturation, valid from weak to SI and requiring only the VS parameter mc, is described. The normalized transconductance efficiency Gm/ID, which is a key figure-of-merit (FoM) for the design of low-power analog circuits, is then derived as a function of IC including the effect of VS. It is then successfully validated from weak to SI with data measured on a 40-nm and two 28-nm bulk CMOS processes. It is then shown that the normalized output conductance Gds/ID follows a similar dependence with IC than the normalized Gm/ID characteristic but with different parameters accounting for drain induced barrier lowering (DIBL). The methodology for extracting the few parameters from the measured ID-VG and ID-VD characteristics is then detailed. Finally, it is shown that the simplified EKV model can also be used for a fully depleted silicon on insulator (FDSOI) and Fin-FET 28-nm processes.

This paper investigates the phase noise in LC oscillators with NMOS cross-coupled pair by means of a linear analysis. The latter includes the impact of noise sources that are often neglected, such as gate leakage shot noise, induced gate noise and all terminal access resistances noise. Despite not considering up-conversion of flicker noise, this linear analysis still provides reliable and useful results, demonstrated by means of a detailed comparison between the analytical description and simulations results from a 40nm and a 28nm CMOS technology.

This article illustrates the use of the inversion coefficient (IC) as the main design parameter to explore the various tradeoffs faced in the design of analog circuits. We start with showing that the same transconductance, gain-bandwidth (GBW) product, or input-referred thermal noise resistance of a common-source (CS) amplifier can be achieved with lower current by shifting the IC toward moderate inversion (MI) at the cost of a slight increase of the transistor aspect ratio and area. In such case the self-loading gate capacitance cannot be ignored, and accounting for it introduces a minimum bias current at an IC that lies in the middle of the MI to achieve a given GBW.