Jean-Louis Cazaux

GaN for space application: almost ready for flight

On the last years, gallium nitride (GaN) technology has made a remarked breakthrough in the world of microwave electronics. Power transistors are now available. 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, after 8 years of GaN studies, experimental results are presented: they open wide the road a revolution inside space-borne electronics: the rise of GaN.

High accuracy wide band analog predistortion linearizer for Telecom satellite transmit section

This paper proposes a new predistortion linearizer module for TWTA allowing to reach high linearity performance on a wide frequency bandwidth for Telecom satellite transmit section. This linearizer module includes a new advanced shape tuning capability associated with an embedded limiting function. A C/I3 improvement of more than 16dB at −7dB IBO per carrier and a NPR increase of 5dB at −3dB OBO were for instance obtained thanks to this new linearizer architecture on the overall 10.7 – 12.75GHz Ku-band (2.05GHz bandwidth). NPR performance is now very close to the optimal theoretical response of the “ideal limiter”.

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.

Ka Band power limiter for satellite channel amplifier

Some Ka-Band payloads request an anti-jamming capacity to be protected against RF interference attacks. This performance can be provided by Thales Alenia Space Ka-Band channel amplifiers thanks to the new Ka-band hard limiter. The power limiter presented in this paper allows to perform this limitation over a 10 dB power dynamic range in the frequency band 20.2 – 20.9 GHz providing in addition tuning capabilities and taking into account the design de-rating rules mandatory for space application.

Microwave power limiters based on RF-MEMS

This paper presents a novel application of MEMS to RF signals: microwave power limiters. A 10.24GHz RF-MEMS based limiter with a 28.2dBm threshold power and a dynamic range of more than 8dB is presented limiting the output power to 27.5dBm with 0.65dB insertion losses. For low power applications, the output limited power can be decreased by biasing RF-MEMS. By biasing the device at 5.2V (Vp = 5.6V), a 10.24GHz power limiter with a 14.2dBm threshold power and a dynamic range of more than 13dB is obtained and the limited output power is only 13.8dBm. Losses of the biased limiter are 1dB. Simulations of a Computer Aided Design (CAD) integrated behavioral model of capacitive RF-MEMS switch have been compared with measured data with good agreement.

Miniature UHF-Band microstrip filter based on a high-permittivity ceramic material

The miniaturization of embarked devices remains a major concern in the space sector. Alternative solutions based on the use of new ceramic materials with very high dielectric permittivity, enhanced electric properties and high temperature stability are worth being investigated. This paper reports on the design of an UHF-microstrip bandpass filter with drastic specifications and based on such a dielectric substrate of relative permittivity εr = 90. Simulation and measurement results highlight some of the possibilities offered by these particular materials.

3D Packaging Technology for Integrated Antenna Front-Ends

Thanks to Vertical Multi-Chip Module packaging technology (MCM-V), a novel concept of integrated antenna feed in Ka band has been developed. This technology enables the integration of active elements very close to the radiating surface, which reduces dramatically the weight and volume of the antenna. In this paper the different technological building blocks are described, and the measurements obtained on the first breadboard are discussed. The promising results obtained should lead to a major breakthrough for active receive antennas, driving down cost and complexity.

1GHz instantaneous wide-band analog predistortion linearizer for new Telecom satellite transmit section

This paper proposes a new predistortion linearizer module for TWTA enabling to use broadband multi-carrier signals for new Telecom satellite transmit sections. A state-of-the-art NPR performance was obtained over the entire 10.7-12.75GHz Ku-band for multi-carrier signals up to, at least, 1GHz instantaneous bandwidth.

Design of high-permittivity ceramic UHF microstrip filter for a space application

The miniaturization of embarked devices remains a major concern in many applications and in particular in the space domain. Alternative solutions based on the use of ceramic materials with very high dielectric permittivity, enhanced electric properties and high temperature stability are worth being investigated. This paper presents the design of a 720 MHz central frequency microstrip bandpass filter. This filter use a ceramic with a relative permittivity ¿r = 90. Simulations, and measurements over a large range of temperature are presented.

Estimation of RF performance from LF measurements: Towards the design for reliability in RF-MEMS

Abstract This paper presents a method which allows the prediction of the RF performance of capacitive RF-MEMS by measuring the UP and DOWN state capacitances. The method is based on the combined use of a very accurate lumped element equivalent circuit model and wafer level measurements of the capacitances in two different states. This approach allows very fast monitoring of the complete RF performance in the entire band, at the cost of a simple (LF) capacitance measurements and an equivalent circuit model extraction. The results presented here demonstrate the efficiency of this technique in tracking or predicting deviation due to manufacturing process dispersions or other device features difficult to account for experimentally.