Jorge Alves Torres

Low noise monolithic down converter for a L band mobile hand set terminal

We report on a 3V monolithic RF front end receiver at 2GHz for a mobile hand set terminal with a two stages LNA, a down converter in a cascode configuration and an output common drain stage. This receiver achieves a maximum conversion gain of 38dB and a minimum noise figure of 2.7dB. This performance was obtained with a low cost MESFET technology with a 0.5¿m gate length process.

K Band SiGe HBT single ended active inductors

The study of monolithic integration of active inductors (AI) on a 0.25µm SiGe BiCMOS technology with 4 metal layers and HBTs with fT=120GHz is presented. Two topologies are presented and their performance discussed. Q values higher than 30 were obtained on a 3.4GHz bandwidth at 28GHz and maximum values as high as 100. Active inductors can be biased with low power, such as 2V with a nominal DC current of 0.6mA. The inductance value is controlled by external bias voltages and adjustments up to 40% were measured. Simple gyrators topologies with only 2 transistors are used for low power consumption and good performance at K Band is proved. The internal parameters of small signal model of HBT were studied and the crucial parameter to enhance the negative resistance and so the Q of the AI was identified.

Grounded active inductors design optimization for fQmax = 14.2GHz using a 130 nm CMOS technology

This paper presents a novel design of an active inductor based on the topology of Manetakis regulated cascode active inductor. The aim of this work is to enhance the manual design of active inductors by using AIDA-C design automation methodology. The circuit is manually designed using a 130 nm CMOS technology in Cadence® to obtain an Inductor operating at 14.2GHz. The sizing of the proposed active inductor has later been optimized using AIDA-C, a state-of-the-art multi-objective multi-constraint circuit-level optimization tool. The AIDA-C circuit sizing tool was able to achieve active inductors solutions with higher quality factor, higher inductance at the operating frequency and also higher bandwidth than the manually designed solution, with the additional surplus of presenting a set of alternative Pareto optimal solutions that enables the designer to choose the most suitable circuit.

SiGe 30GHz active inductor based on cascode gyrator

A monolithic active inductor, to be used up to millimetre wave band lower edge, 30GHz, was implemented with a SiGe technology with 4 metal layers and HBTs with fT=120 GHz. The inductor has a Q greater then 30 on a 4.5GHz bandwidth. The inductance value can be as high as InH. Adjusting the bias conditions an inductance variation over 50% was measured.

30GHz Amplifiers with 0.25μm SiGe BiCMOS

In this paper the possibility of using a low cost SiGe:C BiCMOS technology dedicated to few GHz applications up to 30 GHz is discussed. Spiral inductors with SRF higher than 30 GHz, are not available at the foundry library. Accordingly, inductors with a SRF higher than 45 GHz were obtained, however their Q is only 5 at 30 GHz. The test and modeling technique is presented. The design, implementation and test of a two stages common emitter amplifier without inductors are also presented. It has a 8 dB gain at 28 GHz and 1 dB bandwidth from 5 to 10 GHz with a maximum gain of 23 dB (best frequency range for this technology). The return losses are better then 10 dB from 10 to 35 GHz.

Ku band voltage controlled oscillator on SiGe

In this paper the design and test of a monolithic VCO implemented in a 0.25 mum SiGe technology is presented. The oscillator frequency is changing from 12 till 16 GHz when the control voltage changes from 0 to 2 V. The output power is -10 dBm @ 50 Omega. The total power consumption is 40 mW but 70% is to supply the output buffer amplifier. The predicted VCO phase noise, on the 12 GHz to 16 GHz frequency range is changing from -103 dBc/Hz to -82 dBc/Hz at an offset frequency of 1 MHz.

MMIC Chip-on-Board for wireless communications

We report on the design and Chip-on-Board integration of a monolithic microwave LNA (low noise amplifier) with a monolithic microwave mixer for a mobile L band receiver front- end. GaAs MESFET process with 0.5 micrometer gate length devices was used for the MMICs fabrication. Both MMICs were tested on-wafer and mounted on a soft substrate microstrip carrier (Chip on Board). Experiments are presented.

Double-balanced single-side band mixer for millimeter wave mobile communications

In this paper the design of single side band mixers to convert C to V band signals is presented. A step by step design technique, based on harmonic balance simulations is described. The mixer devices are Schottky diodes compatible with a GaAs MESFET technology. The mixers were optimized for minimum conversion loss over the widest possible bandwidth when used as both up or downconverters in order to be used on a large number of applications. The experiments show, for both applications, a minimum conversion loss in the range of 8 to 9dB and a 3dB bandwidth larger than 6GHz.

Multifunction MMIC for millimeter wave mobile communications

In this paper the design of a multifunction MMIC for millimeter wave mobile communication systems is presented. The MMIC is a single balanced mixer that can work as both up and down converter between C and V band and as a BPSK modulator. A step by step design technique is described, based on harmonic balance simulations. The mixer devices are Schottky diodes, and all the components are integrated in a MMIC chip using GaAs MESFET technology. The mixers were optimized to have a similar performance as both up or down converter, between C and V bands and a bandwidth greater than 4 GHz. The experiments show, for both applications a minimum conversion loss in the range of 6 to 8 dB and a -3dB bandwidth larger than 7 GHz.