Babak Heydari

Millimeter-Wave Devices and Circuit Blocks up to 104 GHz in 90 nm CMOS

A systematic methodology for layout optimization of active devices for millimeter-wave (mm-wave) application is proposed. A hybrid mm-wave modeling technique was developed to extend the validity of the device compact models up to 100 GHz. These methods resulted in the design of a customized 90 nm device layout which yields an extrapolated of 300 GHz from an intrinsic device . The device is incorporated into a low-power 60 GHz amplifier consuming 10.5 mW, providing 12.2 dB of gain, and an output of 4 dBm. An experimental three-stage 104 GHz tuned amplifier has a measured peak gain of 9.3 dB. Finally, a Colpitts oscillator operating at 104 GHz delivers up to 5 dBm of output power while consuming 6.5 mW.

Low-Power mm-Wave Components up to 104GHz in 90nm CMOS

A customized 90nm device layout yields an extrapolated fmax of 300GHz. The device is incorporated into a low-power 60GHz amplifier consuming 10.5mW, providing 12dB of gain, and an output P1dB of 4dBm. An experimental 3-stage 104GHz amplifier has a measured peak gain of 9.3dB. Finally, a Colpitts oscillator at 104GHz delivers up to -5dBm of output power while consuming 6mW.

30 GHz CMOS Low Noise Amplifier

30 GHz low noise amplifier was designed and fabricated in a 90 nm digital CMOS process. The mm-wave amplifier has a peak gain of 20 dB at 28.5 GHz and a 3 dB bandwidth of 2.6 GHz with the input and output matching better than 12 dB and 17 dB over the entire band respectively. The NF is 2.9 dB at 28 GHz and less than 4.2 dB across the band and it can deliver 2 dBm of power to a matched load at its 1 dB compression point. The amplifier has a measured linearity of IIIP3=-7.5 dBm. It consumes 16.25 mW of power using a low supply voltage of 1 V and occupies an area (excluding the pads) of 1600 mum x 420 mum.

BSIM5 MOSFET Model

This paper summarizes BSIM5 MOSFET model for aggressively scaled CMOS technology which was released recently. Various new physical effects are timely addressed in the new physical core including more accurate physics that is easily extended to non-charge-sheet, completely continuous current and derivatives, and extendibility to non-traditional CMOS based devices including SOI and double-gate MOSFETs. The flexible architecture also enables the carry-over of BSFM4s accurate modeling of numerous device behaviors attributable to device physics or technologies.

A 60 GHz Power Amplifier in 90nm CMOS Technology

A two-stage 60 GHz 90 nm CMOS PA has been designed and fabricated. The amplifier has a measured power gain of 9.8 dB. The input is gain matched while the output is matched to maximize the output power. The measured P-1dB = 6.7 dBm with a corresponding power added efficiency of 20%. This amplifier can be used as a pre-driver or as the main PA for short range wireless communication. The output power can be boosted with on-chip or spatial power combining.

Network Modularity is essential for evolution of cooperation under uncertainty

Cooperative behavior, which pervades nature, can be significantly enhanced when agents interact in a structured rather than random way; however, the key structural factors that affect cooperation are not well understood. Moreover, the role structure plays with cooperation has largely been studied through observing overall cooperation rather than the underlying components that together shape cooperative behavior. In this paper we address these two problems by first applying evolutionary games to a wide range of networks, where agents play the Prisoners Dilemma with a three-component stochastic strategy, and then analyzing agent-based simulation results using principal component analysis. With these methods we study the evolution of trust, reciprocity and forgiveness as a function of several structural parameters. This work demonstrates that community structure, represented by network modularity, among all the tested structural parameters, has the most significant impact on the emergence of cooperative behavior, with forgiveness showing the largest sensitivity to community structure. We also show that increased community structure reduces the dispersion of trust and forgiveness, thereby reducing the network-level uncertainties for these two components; graph transitivity and degree also significantly influence the evolutionary dynamics of the population and the diversity of strategies at equilibrium.

A 60-GHz 90-nm CMOS cascode amplifier with interstage matching

The design of a 60 GHz cascode amplifier in a 90 nm technology is described. The amplifier uses an interstage matching to increase the gain and to provide a better power match between the common-source and the common-gate transistor of the cascode device. Both the common-source and the common-gate transistor make use of an optimized round-table layout, which minimizes all terminal resistances and thus improves the mm-wave performance of the nMOS transistors. A record fmax of 300 GHz is achieved for a 40 mum round-table nMOS in 90 nm CMOS. The cascode amplifier achieves a gain of 7.5 dB at 60 GHz with a DC power consumption of only 6.7 mW. When compared to a shared-junction cascode amplifier or a two-stage common-source cascade amplifier, the presented cascode amplifier is favorable in terms of power gain and DC power consumption

Nanoscale CMOS for mm-Wave Applications

Aggressive technology scaling of CMOS has culminated in a low-cost high volume commercial process technology with Ft > 150 GHz and Fmax > 200 GHz. This paper discusses the key trends in CMOS scaling that have led to this level of performance and attempts to predict the performance down to 45 nm. The design of active and passive components in CMOS for power gain and low noise are discussed in detail and unique features of CMOS technology are highlighted. Experimental results derived from a 60 GHz amplifier in 90 nm CMOS and a complete 60 GHz front-end receiver in 130 nm CMOS are reported.

Charge-based core and the model architecture of BSIM5

The paper outlines the charge-based core and the architecture of the BSIM5 MOSFET model for sub-100 nm CMOS circuit simulation. The BSIM5 model is a continuous, completely symmetric and accurate non charge-sheet based MOS transistor model derived from the basic device physics, including various physics effects. Comparison of the inversion charge between the BSIM5 prediction and self-consistent numerical solution shows good agreement. The demonstration of fully symmetric characteristics of BSIM5, such as channel current and its high-order derivative in the Gummel symmetry test, and charge and trans-capacitances in a SPICE simulation, also implies BSIM5 is the physically symmetric MOSFET model valid for RF-analog circuit simulations.

Emergence of Modularity in System of Systems: Complex Networks in Heterogeneous Environments

Effective use of modularity in distributed systems is key to accommodating the complexity arising from having diverse requirements and stakeholders and increased environmental uncertainties. Moreover, modularity facilitates efficient dynamic resource allocation in the system. In this paper, a formal framework that links various classes of systems modularity to distributed decision complexities is presented by formulating modularity as an emergent phenomenon arising from environmental heterogeneity. This paper also demonstrates behavioral and mathematical formulations of the problem and agent-based simulation of sample networked systems to verify the results.