Claude Drevon

Gamma radiation effects on RF MEMS capacitive switches

Dielectric-based RF MEMS capacitive switches were fabricated and characterized for their response to dielectric charging, thermal storage and cycling and to total dose gamma irradiations. The evolution of the switch electromechanical and RF characteristics (actuation and releasing voltages, insertion losses, isolation) were evaluated as a function of the applied stress (temperature or total ionizing dose). It is indicated that the thermal stress has a relatively minor impact on the switches (the switches remained functional with nearly the same electrical properties). Under our particular test conditions, C(V) and S-parameters measurements show that gamma radiation has low to moderate effects on the components behavior.

Design to reliability shielded vertical interconnection applied to microwave Chip Scale Packaging

This paper presents the electrical design, measurement and reliability tests of a shielded vertical interconnection dedicated to microwave solder-mount packages. Electromagnetic simulations show very good results up to 20 GHz. Test samples have been designed and manufactured. Electrical results are in accordance with the simulations with insertion loss lower than 0.1 dB up to 20 GHz for the proposed interconnection. Reliability tests of present no degradation of the after 500 thermal cycles in the [¿55°C, +125°C] temperature range.

Prospective and issues for GaN microwave electronics into space satellites

On the very last months, gallium nitride (GaN) technology has made a remarked breakthrough in the world of microwave electronics with the announcement of commercially available power transistors. Those striking news follow several publicized results that had been published since few years. How this GaN technology would impact space- borne units is now a priority concern. Although the power capability of GaN technology is the first obvious profit, GaN could also be used for other applications like low noise amplifiers, mixers and probably more. The high sustainable temperature of GaN transistors is most striking advantage for in-flight use. This is connected to packaging design which is also experiencing a lot of activities and quick progresses. Of course, space application is dependent upon the full demonstration of reliability and this constitutes another field of investigation. Finally, our very first, promising, experimental results are presented: they open wide the road a revolution inside space-borne electronics: the rise of GaN.

Is hermitic encapsulation of GaAs MMIC still required for space applications

This paper presents the introduction of the nonhermetic encapsulation of microwave hybrids for space application. Thanks to the improvement for many years now of organic materials, it is now realistic to propose a glob top encapsulation of GaAs MMIC on printed circuit boards. To validate this packaging approach, a reliability test-plan is proposed based on humidity tests, life tests and thermal cyclings in agreement with standard space quality requirements. Six modules per test-file have been manufactured. No failures are reported by visual inspection and on electrical characteristics at the end of the three test-files.

Optimised thermal and microwave packaging for wide-band gap transistors : diamond & flip chip

Wide-band gap (WBG) transistors give a real breakthrough for power devices compared to silicon (Si) and gallium arsenide (GaAs) components. However, for space applications, the high power density of WBG transistors makes the thermal management critical and requires thermal investigations. Some packaging solutions dedicated to those power transistors are presented in this paper. The focus is made on diamond-based packaging with two topologies. In the first one, the die is soldered on a diamond carrier. In the second one, it is flip chip bonded on a diamond circuit. Thermal simulations, thermal cycling and electrical measurement results are given for both configurations.

MEMS-based MCM VCO for space applications

This paper presents the implementation and test of prototype RF MEMS based voltage controlled oscillators (VCO) for space applications. RF MEMS tunable capacitors based on a dual gap architecture have been manufactured with a thin film technology on silicon and have demonstrated high tuning ratio (Cmax/Cmin ~ 4) and high Q factors (up to 100) with a good reproducibility. These tunable capacitors have been integrated as frequency tuning element in the LC tank of multi chip modules (MCM) VCO operating around 1.6 GHz with a tuning range greater than 16% and a phase noise as low as -125 dBc/Hz at 1 MHz offset from the carrier

Narrow band micro-machined band pass filter and a surface-mountable topology

A 27.88 three-pole 1.8% bandwidth silicon micro-machined filter with 50 dB rejection is presented. On a single resonator, a quality factor of 602 has been measured and the filter exhibits 2.9 dB of insertion losses. A 30.04 GHz two-pole silicon micro-machined filter with a simple planar integration is also proposed. The excitation is made from the top of the shielding substrate of a membrane supported micro-machined filter. Packaging and inter-connection are included in the design. The whole filter exhibits 1.8 dB of insertion losses. Such filter can be easily integrated by flip-chip technology.

Non hermetic microwave packaging : a reality for space application

This paper presents the introduction of the non hermetic encapsulation of microwave hybrids for space application through the development of a new generation of low noise amplifier modules for a feed array fed reflector antenna for multimedia applications in Ka-band. Thanks to the improvement for many years now of organic materials, it is now realistic to propose advanced packaging solutions based on the chip on board approach with glob top encapsulation of active devices on printed circuit boards. To validate this packaging approach, reliability test-plans were proposed for each process/material (board substrate, assembly of components, module connection and glob top encapsulation) in agreement with standard space quality requirements. No failure is reported after visual inspection and on electrical characteristics at the end of the reliability test-files

Use of RF MEMS and micromachined parts to realize highly integrated V band active feed for satellite antennas

Micromachining and microelectromechanical systems (MEMS) technologies can play a key role in miniaturization of satellite antenna front-ends. Alcatel Alenia Space France has demonstrated for the first time the operation of a V band integrated active feed combining 3D stacking concepts and micromachining technologies. The realized integrated module size is 35 times 35 mm2 with a thickness of 7 mm including miniaturized DC and RF connectors. In this paper, we present the latest test results obtained on this MEMS based active antenna

Design of a Micromachined Band-Pass Filter with Insertion of the Coplanar Accesses in the Resonator

In this article, the design of a two poles micro-strip micro-machined planar filter is presented at 28 GHz with a 5% bandwidth with an optimization methodology of the quality factor in order to decrease losses. Furthermore this article presents a new connection between the resonators in micro-strip technology and the coplanar accesses. We propose a slot in the quarter wave-length resonator which is directly connected to coplanar input lines. The coplanar to micro-strip transition between the circuit and external accesses is included as a part of the synthesis. This technique is quite easy to achieve and permit to win one step in a filter design.