Nouvelle topologie d’un filtre passe-bande RF du 4ème ordre accordable à base d'inductances actives

Dans cet article, nous présentons la topologie d'un filtre actif radiofréquences du second ordre. Ce filtre utilise une inductance active basée sur le principe du gyrateur. La structure de cette dernière met en oeuvre des transistors MOSFETs. Les paramètres technologiques employés sont ceux de la technologie CMOS 0,35 μm d’AMS. Nous montrons d'abord l'importance du choix du modèle "petits signaux" des transistors pour une étude théorique. Nous montrons ensuite que ce filtre peut être accordé en fréquence centrale et en bande passante. Nous montrons enfin que le principe peut être étendu aux filtres d'ordre supérieur

Etude de structures actives simulant une résistance négative intégrable dans des filtres RF

Dans ce papier, nous présentons les résultats d’une étude détaillée de trois circuits simulant une résistance négative. Ils sont basés sur une contre réaction active obtenue avec différents configurations de base de transistors (source commune, drain commun et grille commune). Cette résistance ayant pour but de compenser les pertes dans le résonateur constituant le filtre actif. Le principe de fonctionnement de ces circuits de compensation est analysé théoriquement et validé par des simulations en technologie CMOS 0.35μm du fondeur AMS (Austria Micro Systems), en utilisant le logiciel ADS

Optimization of multiheterojunction AlGaAs/GaAs HEMT's for microwave power amplification

A theoretical and experimental study concerning a three channels power HEMT is presented. The structure has been, first, optimized using an adequate simulation. Then many technological realizations have been achieved at the laboratory. Measurements performed with these devices give results very encouraging and permit to foresee superior performances relatively to that of GaAs power MESFET's

Лицензии «creative commons»

A nonlinear model of MESFETs and HEMTs capacitances suitable for implementation in commercial circuit design software is presented. The model is based upon the deter­mination of the nonlinear bias dependent charge equations. A comparison is made between capacitance values coming from PHEMT characterization and capacitance values derived from the model

AVALANCHE AND TUNNELING BREAKDOWN MECHANISMS IN HEMT'S POWER STRUCTURES

Cet article expose une étude sur le phénomène de claquage dans les HEMTs de puissance AlGaAs/GaAs. Il fait usage, d'une part, de résultats expérimentaux obtenus sur différents composants test et, d'autre part, de modélisations prenant en compte soit l'ionization soit l'effet tunnel. Cette approche apporte une nouvelle compréhension sur les rôles respectifs de ces deux effets dans le declenchement du claquage et permet de définir des règles de construction.The present paper reports a study on the breakdown phenomenon in AlGaAs/GaAs power HEMT'S. It uses, on one hand, experimental results carried out on various test devices and, on the other hand, modeling taking into account either ionization or tunneling effects. Such an approach gives a new understanding on the respective roles of these two effects in the breakdown occurrence and allows to define design rules

A Fully Integrated SiGe BiCMOS MMIC Front-end for Using in the ISM Bands

International audienc

A 2.4-GHz Front-end System Design for WLAN Applications using 0.35μm SiGe BiCMOS Technology

International audienceA 2.4GHz front-end system design for wide spectrum WLAN applications is presented in a 0.35 μm SiGe BiCMOS Technology. This transceiver front-end contains a receive (Rx) chain with a two-stage cascode low noise amplifier (LNA) and an active down-conversion Rx mixer, and a transmit (Tx) chain composed of a Gilbert-Cell core up-conversion Tx mixer and a high-gain Driver Amplifier (DA). The high linear LNA shows a gain of 15.5 dB, an noise figure (NF) of 2.28 dB and an input- referred third-order intercept point (IP3) of +2.4 dBm with 1-dB gain bandwidth (BW) of 1.5 GHz. The single-balanced Rx mixer exhibited a gain and 1-dB gain BW of +6.8 dB and 1.5 GHz. Also a double-balanced Tx mixer with a gain and input/output return loss of -1.3dB and below -35dB, respectively, and a DA with a gain and output-referred IP3 of +29.2dB and +21.2dBm, respectively, is developed. The NF, input-referred IP3 and DC power consumption of Rx string (from antenna to Rx mixer) were achieved 4.4 dB, -15.4 dBm and 30 mW respectively. The output-referred IP3 and power consumption of Tx chain were +20.5 dBm and 125 mW, respectively

A 3-Mode Switched-Gain Low Noise Amplifier for Wireless Bands Applications Using an MMIC Technology

International audienceThis paper describes a 2.4 GHz single-ended switched gain low noise amplifier (SG-LNA) in a 0.35 mum SiGe BiCMOS process. In the design, specific architecture decisions were made in consideration of system-on-chip implementation. The architecture profits from a two cascode stage topology with a shunt resistive feedback in the first cascade-topology stage. The SG-LNA achieved a maximum small signal gain of 34.3 dB within input 1-dB compression point (ICP1dB) of -22 dBm in high-gain mode (HGM), a gain of 25.4 dB within ICP1dB of -13.8 dBm in medium-gain mode (MGM) , and a minimum gain of 18.3 dB within ICP1dB of -6.8 dBm in low-gain mode (LGM). The noise figures (NF) are 2.9 dB, 5.5 dB and 5.9 dB in HGM, MGM and LGM, respectively. Because of using a Common-Gate topology as an active input matching, the SG-LNA presented a good input and output return losses in all modes. All biases applied are active. The SG-LNA consumes a maximum DC current of 42 mA from a 3.3 volt DC supply

Front-end components design for IEEE 802.11B/G, Applications using an MMIC technology

International audienc