this paper, we review the Bluetooth technology, a new universal radio interface enabling electronic devices to connect and communicate wirelessly via short-range connections. Motivations for the air interface design and radio requirement decisions are discussed. Frequency hopping, interference resistance, and the concepts of ad hoc connectivity and scatternets are explained in detail. Furthermore, Bluetooth characteristics enabling low-cost single-chip implementations and supporting low power consumption are discussed

Abstract—Precision amplifiers dominate the power dissipation in most high-speed pipelined analog-to-digital converters (ADCs). We propose a digital background calibration technique as an enabling element to replace precision amplifiers by simple powerefficient open-loop stages. In the multibit first stage of a 12-bit 75-MSamples/s proof-of-concept prototype, we achieve more than 60 % residue amplifier power savings over a conventional implementation. The ADC has been fabricated in a 0.35- m double-poly quadruple-metal CMOS technology and achieves typical differential and integral nonlinearity within 0.5 LSB and 0.9 LSB, respectively. At Nyquist input frequencies, the measured signal-to-noise ratio is 67 dB and the total harmonic distortion is 74 dB. The IC consumes 290 mW at 3 V and occupies 7.9 mmP. Index Terms—Analog-to-digital conversion, adaptive systems, calibration, CMOS analog integrated circuits, linearization techniques, parameter estimation. I.

Abstract—In this paper the distortion components are defined for elementary transistor stages such as a single-transistor amplifier and a differential pair using bipolar transistors or MOST’s. Moreover, the influence of feedback is examined. Numerical examples are given for sake of illustration. Index Terms—Amplifiers, distortion, feedback, intercept point. I.

An approach is presented for the analysis of the nonlinear behavior of analog integrated circuits. The approach is based on a variant of the Volterra series approach for frequencydomain analysis of weakly nonlinear circuits with one input port, such as amplifiers, and with more than one input port, such as analog mixers and multipliers. By coupling numerical results with symbolic results, both obtained with this method, insight into the nonlinear operation of analog integrated circuits can be gained. For accurate distortion computations, the accuracy of the transistor models is critical. A MOS transistor model is discussed that allows us to explain the measured fourth-order nonlinear behavior of a 1-GHz CMOS upconverter. Further, the method is illustrated with several examples, including the analysis of an operational amplifier up to its gain-bandwidth product. This example has also been verified experimentally. Index Terms---Analog integrated circuits, harmonic distortion, nonlinear ...

Abstract—Envelope distortion in transconductance mixers is analyzed in this paper. The analysis consists of a simplified theoretical study, simulation results, and measurements about several implemented mixers. The studied mixers are active single-balanced and double-balanced structures. A theoretical mismatch analysis is carried out instead of a complex mixer nonlinearity analysis; this gives an intuitive sense of even-order nonlinearity in balanced mixers, and provides information about the fundamental restrictions of second-order input intercept point (IIP2) and the relations of different imbalances to actual performance. The analysis uses a number of simplifying assumptions, but without losing generality. The IIP2 is sensitive to any mismatch in a differential circuit topology. It will be shown that an excellent IIP2 can be achieved in slightly imbalanced conditions by a controllable mismatch device. Index Terms—BiCMOS analog integrated circuits, DC offset, direct conversion, envelope distortion, IIP2, mismatch, mixers, nonlinearity, radio receivers, second-order distortion. I.

Modeling frequency-dependent nonlinear characteristics of complex analog blocks and subsystems is critical for enabling efficient verification of mixed-signal system designs. Recent progress has been made for constructing such macromodels, however, their accuracy and/or efficiency can break down for certain problems, particularly those with high-Q filtering. In this paper we explore a novel hybrid approach for generating accurate analog macromodels for time-varying weakly nonlinear circuits. The combined benefits of nonlinear Padé approximations and pruning by exploitation of the system’s internal structure allows us to construct nonlinear circuit models that are accurate for wide input frequency ranges, and thereby capable of modeling systems with sharp frequency selectivity. Such components are widely encountered in analog signal processing and RF applications. The efficacy of the proposed approach is demonstrated by the modeling of large time-varying nonlinear circuits that are commonly found in these application areas. 1.

This paper presents a novel method to automatically generate symbolic expressions for both linear and nonlinear circuit characteristics using a template-based fitting of numerical, simulated data. The aim of the method is to generate convex, interpretable expressions. The posynomiality of the generated expressions enables the use of efficient geometric programming techniques when using these expressions for circuit sizing and optimization. Attention is paid to estimating the relative `goodness-of-fit' of the generated expressions. Experimental results illustrate the capabilities of the approach.

Abstract — Efficient algorithms are presented to generate approximate expressions for transfer functions and characteristics of large linear analog circuits. The algorithms are based on a compact determinant decision diagram (DDD) representation of exact transfer functions and characteristics. Several theoretical properties of DDDs are characterized, and three algorithms, namely, based on dynamic programming, based on consecutive k-shortest path based, and based on incremental k-shortest path, are presented in this paper. We show theoretically that all three algorithms have time complexity linearly proportional to |DDD|, the number of vertices of a DDD, and that the incremental kshortest path based algorithm is fastest and the most flexible one. Experimental results confirm that the proposed algorithms are the most efficient ones reported so far, and are capable of generating thousands of dominant terms for typical analog blocks in CPU seconds on a modern computer workstation. Index Terms — analog symbolic analysis, circuit simulation, determinant decision diagrams, matrix determinant, behavioral modeling I.

Universal Mobile Telecommunication System (UMTS) front end design is challenging because of the need to optimize power while satisfying a very high dynamic range requirement. Dealing with this design problem at the transistor level does not allow to explore efficiently the design space, while using behavioral models does not allow to take into consideration important second-order effects. We present an extension of the platform-based design methodology originally developed for digital systems to the analog domain to conjugate the need of higher levels of abstraction to deal with complexity as well as the one of capturing enough of the actual circuit-level characteristics to deal with second order effects. We show how this methodology applied to the UMTS front-end design yields power savings as large as 47% versus an original hand optimized design. 1.

This paper reviews different techniques used in the literature to analyze distortion in analog integrated circuits. It concentrates on analytical techniques rather than on numerical techniques. Techniques such as Volterra series, harmonic injection method, and modeling of circuit non-linearities, are discussed with emphasis on the last two tech-niques. The theory behind each technique is explained, and they are compared together. In general, distortion is one of the most important undesired effects that appear in analog circuits due to non-linearities, which have many sources in integrated circuits [1]. In mixed-signal integrated circuits most of the functions are implemented in the digital domain, leaving the analog designer with tough specification to design analog circuits.