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International audience ; The reliability and robustness of electronic subsystems dedicated to control and communications in the aerospace sector is more than ever one of the key points for safety and security, essentially during landing operations. As aircraft manufacturers have to diversify their mean of communication system's control (Full-Duplex and System), the reliability can be improved both by setting redundant remote networks, and also by using matched technologies for increased performances and robustness: the wide band-gap Gallium Nitride technology (GaN) newly developed fits perfectly to the requirements of systems such as Microwave Landing System (MLS) or Distance Measuring Equipments (DME) used during the final landing approach. Actually, GaN technology takes advantage of a natural immunity to electromagnetic perturbations, and is suitable for circuit design in the RF frequency band (up to 5 GHz for aircraft applications). The GaN based circuits are able to improve transceiver's efficiency (and so the radio-link budget) thanks to their low noise figure (receiver) and high output power (transmitter), reducing digital bit error rate during the code demodulation. This point is crucial while electronic runs in an urban environment. Moreover, the next electronic systems developed for " composite aircraft " will be more exposed to high electric field and CEM problems in circuits. Furthermore, this GaN integrated technology allows a reduction of volume for transmitter's subsystems , and is easy to setup (aircraft maintenance): the risk of immobilisation during the aircraft exploitation will be reduced and his maintainability will be easier. Finally, this technology is also perfectly suited for ground navigation control systems such as radar. This work presents the challenge for civil and military future avionic systems by making use of GaN based technologies.

International audience ; The reliability and robustness of electronic subsystems dedicated to control and communications in the aerospace sector is more than ever one of the key points for safety and security, essentially during landing operations. As aircraft manufacturers have to diversify their mean of communication system's control (Full-Duplex and System), the reliability can be improved both by setting redundant remote networks, and also by using matched technologies for increased performances and robustness: the wide band-gap Gallium Nitride technology (GaN) newly developed fits perfectly to the requirements of systems such as Microwave Landing System (MLS) or Distance Measuring Equipments (DME) used during the final landing approach. Actually, GaN technology takes advantage of a natural immunity to electromagnetic perturbations, and is suitable for circuit design in the RF frequency band (up to 5 GHz for aircraft applications). The GaN based circuits are able to improve transceiver's efficiency (and so the radio-link budget) thanks to their low noise figure (receiver) and high output power (transmitter), reducing digital bit error rate during the code demodulation. This point is crucial while electronic runs in an urban environment. Moreover, the next electronic systems developed for " composite aircraft " will be more exposed to high electric field and CEM problems in circuits. Furthermore, this GaN integrated technology allows a reduction of volume for transmitter's subsystems , and is easy to setup (aircraft maintenance): the risk of immobilisation during the aircraft exploitation will be reduced and his maintainability will be easier. Finally, this technology is also perfectly suited for ground navigation control systems such as radar. This work presents the challenge for civil and military future avionic systems by making use of GaN based technologies.

International audience ; The reliability and robustness of electronic subsystems dedicated to control and communications in the aerospace sector is more than ever one of the key points for safety and security, essentially during landing operations. As aircraft manufacturers have to diversify their mean of communication system's control (Full-Duplex and System), the reliability can be improved both by setting redundant remote networks, and also by using matched technologies for increased performances and robustness: the wide band-gap Gallium Nitride technology (GaN) newly developed fits perfectly to the requirements of systems such as Microwave Landing System (MLS) or Distance Measuring Equipments (DME) used during the final landing approach. Actually, GaN technology takes advantage of a natural immunity to electromagnetic perturbations, and is suitable for circuit design in the RF frequency band (up to 5 GHz for aircraft applications). The GaN based circuits are able to improve transceiver's efficiency (and so the radio-link budget) thanks to their low noise figure (receiver) and high output power (transmitter), reducing digital bit error rate during the code demodulation. This point is crucial while electronic runs in an urban environment. Moreover, the next electronic systems developed for " composite aircraft " will be more exposed to high electric field and CEM problems in circuits. Furthermore, this GaN integrated technology allows a reduction of volume for transmitter's subsystems , and is easy to setup (aircraft maintenance): the risk of immobilisation during the aircraft exploitation will be reduced and his maintainability will be easier. Finally, this technology is also perfectly suited for ground navigation control systems such as radar. This work presents the challenge for civil and military future avionic systems by making use of GaN based technologies.

International audience ; Newly developed GaN technology offers great potential for military and space, as well as some high volume applications. The devices are grown on different substrates (sapphire, silicon and silicon carbide), involving differences on the performances, price, and technological complexity. The design of a fully integrated transceiver in such a technology necessitates great noise performances for the linear (Low Noise Amplifiers, LNA) and non-linear (Voltage Controlled Oscillator, VCO) applications. The low noise figure already published on this technology up to X-band, associated to the capability to handle high power levels avoid the integration of a limiter stage that deteriorates the overall noise figure in conventional architectures. The low frequency noise performances are useful both for the technology assessment (maturity's indicator) and for the non-linear circuit design (conversion to phase noise around the carrier). This paper presents the noise performances of AlGaN/GaN HEMT grown on SiC substrate. Low frequency noise contributors in the Ohmic and saturated regime are discussed. Residual phase noise characterization at 10 GHz correlates the results about the noise sources involved, and linear high frequency noise figure measurements are also presented, targeting respectively VCO and LNA applications.

International audience ; Newly developed GaN technology offers great potential for military and space, as well as some high volume applications. The devices are grown on different substrates (sapphire, silicon and silicon carbide), involving differences on the performances, price, and technological complexity. The design of a fully integrated transceiver in such a technology necessitates great noise performances for the linear (Low Noise Amplifiers, LNA) and non-linear (Voltage Controlled Oscillator, VCO) applications. The low noise figure already published on this technology up to X-band, associated to the capability to handle high power levels avoid the integration of a limiter stage that deteriorates the overall noise figure in conventional architectures. The low frequency noise performances are useful both for the technology assessment (maturity's indicator) and for the non-linear circuit design (conversion to phase noise around the carrier). This paper presents the noise performances of AlGaN/GaN HEMT grown on SiC substrate. Low frequency noise contributors in the Ohmic and saturated regime are discussed. Residual phase noise characterization at 10 GHz correlates the results about the noise sources involved, and linear high frequency noise figure measurements are also presented, targeting respectively VCO and LNA applications.

The term pole-zero identification refers to obtaining the poles and zeros of a linear (or linearized) system described by its frequency response. This is usually done using optimization techniques (such as least squares, maximum likelihood estimation, or vector fitting) that fit a given frequency response of the linear system to a transfer function defined as the ratio of two polynomials [1], [2]. This kind of linear system identification in the frequency domain has numerous applications in a wide variety of engineering fields, such as mechanical systems, power systems, and electromagnetic compatibility. In the microwave domain, rational approximation is increasingly used to obtain black-box models of complex passive structures for model order reduction and efficient transient simulation. An extensive bibliography on the matter can be found in [3]-[6]. In this article, we focus on a different application of pole-zero identification. We review the different ways in which pole-zero identification can be applied to nonlinear circuit design, for power-amplifier stability analysis, and more. We provide a comprehensive view of recent approaches through illustrative application examples. Other uses for rational-approximation techniques are beyond the scope of this article. ; This work was supported in part by the French Space Agency (CNES) under projects R-S10/TG-0001-019 and R-S14/TG-0001-019; by a joint Ph.D. research grant from CNES and Thales Alenia Space, France; by project TEC2015-67217-R (MINECO/FEDER); and by the Basque Country Government through project IT1104-16.