An updated version of a 1985 tutorial paper on active filters using operational transconductance amplifiers (OTAs) is presented. The integrated circuit issues involved in active filters (using CMOS transconductance amplifiers) and the progress in this field in the last 15 years is addressed. CMOS transconductance amplifiers, nonlinearised and linearised, as well as frequency limitations and dynamic range considerations are reviewed. OTA-C filter architectures, current-mode filters, and other potential applications of transconductance amplifiers are discussed.

CMOS transconductance amplifiers, architectures and active filters: a tutorial

This work analyzes both by simulations and measurements the substrate crosstalk performances of various Silicon-On-Insulator (SOI) technologies, and compares them to those of normal bulk CMOS process. The influence of various parameters, such as substrate resistivity, buried oxide thickness and distance between devices, is investigated. The use of capacitive guard rings is proposed, and their effectiveness is demonstrated. A simple RC model has been developed to allow a deep understanding of these phenomena as well as to simplify future studies of more complex systems. The superiority of high-resistivity SIMOX substrates over standard SOI and bulk is finally demonstrated.

Substrate crosstalk reduction using SOI technology

An RF switch circuit and method for switching RF signals that may be fabricated using common integrated circuit materials such as silicon, particularly using insulating substrate technologies. The RF switch includes switching and shunting transistor groupings to alternatively couple RF input signals to a common RF node, each controlled by a switching control voltage (SW) or its inverse (SW_), which are approximately symmetrical about ground. The transistor groupings each comprise one or more insulating gate FET transistors connected together in a “stacked” series channel configuration, which increases the breakdown voltage across the series connected transistors and improves RF switch compression. A fully integrated RF switch is described including control logic and a negative voltage generator with the RF switch elements. In one embodiment, the fully integrated RF switch includes an oscillator, a charge pump, CMOS logic circuitry, level-shifting and voltage divider circuits, and an RF buffer circuit.

Switch Circuit and Method of Switching Radio Frequency Signals

This work presents a systematic comparative study of the influence of various process options on the analog and RF properties of fully depleted (FD) silicon-on-insulator (SOI), partially depleted (PD) SOI, and bulk MOSFET's with gate lengths down to 0.08 /spl mu/m. We introduce the transconductance-over-drain current ratio and Early voltage as key figures of merits for the analog MOS performance and the gain and the transition and maximum frequencies for RF performances and link them to device engineering. Specifically, we investigate the effects of HALO implantation in FD, PD, and bulk devices, of film thickness in FD, of substrate doping in SOI, and of nonstandard channel engineering (i.e., asymmetric Graded-channel MOSFETs and gate-body contacted DTMOS).

Influence of device engineering on the analog and RF performances of SOI MOSFETs

In this paper, a de-embedding method is proposed for conducting accurate on-wafer device measurements in the gi- gahertz range. The method addresses issues of substrate coupling and contact effects and is therefore suitable for measurements with lossy technologies such as CMOS. The method assumes a probe-tip two-port calibration performed with well-known techniques and impedance substrates. By employing a physical interpretation of the test-fixture, the method alleviates a number of known prob- lems with common de-embedding procedures. Four distinct math- ematical steps are suggested to de-embed parasitics for the test-fix- ture to give an accurate measurement of the device under test. By introducing a simple compensation factor for in-fixture stan- dard imperfections, the proposed method allows large devices to be measured with high accuracy. The applicability of the method is demonstrated with measurements up to 12 GHz.

A Four-Step Method for De-Embedding Gigahertz

An extraction method for small-signal model parameters of Silicon-on-Insulator (SOI) MOS transistors is presented. This technique allows to obtain the intrinsic and extrinsic parameter values for a high frequency small-signal model directly from scattering parameter measurements. Only two sets of measured S-parameters are required, one set in the zero-bias condition at relatively high frequency to obtain values of series parasitic elements (R/sub G/, R/sub D/ and R/sub S/) and the other in the frequency band and the bias conditions of interest to determine the parallel elements of the equivalent circuit.

Direct extraction method of SOI MOSFET transistors parameters

Thin film fully depleted silicon-on-insulator CMOS technology, devices and circuits for RF applications are presented. These submicron MOSFET transistors can achieve a maximum oscillation frequency of 30 GHz for a 1 V power supply. This kind of performance and the advantages of the SOI transistors fit the needs for low-voltage low-power RF applications. To demonstrate the capabilities of this technology we present a single stage OTA with a f/sub T/ of 1.1 GHz and /spl phi//sub M/ of 30/spl deg/, and two CMOS mixers with exceptional linearity results.

Advanced SOI CMOS technology for RF applications

Investigation of salicide processes for thin-film SOI microwave applications

A new extraction scheme is proposed, which allows to determine all the equivalent circuit elements values from S-parameters measurements at a single bias point in saturation. Exploiting the specific shape of a set of impedance loci, the new procedure uses linear regression techniques to solve the extraction problem. The resulting algorithm is very simple and efficient when compared to optimiser-driven approaches. Taking into account the nonquasi-static (NQS) effects the extracted model allows to characterize the SOI MOSFET's up to 40 GHz.

Direct Extraction of the Nonquasi-Static Small-Signal Model of MOSFET's

http://ieeexplore.ieee.org/iel5/4138558/4138559/04138600.pdf

R. Gillon

Papers

Direct extraction method of SOI MOSFET transistors parameters

Advanced SOI CMOS technology for RF applications

Investigation of salicide processes for thin-film SOI microwave applications

Direct Extraction of the Nonquasi-Static Small-Signal Model of MOSFET's

Determining thereferenceimpedance of on-wafer TLR calibrationson tossy substrates