-
[show abstract]
[hide abstract]
ABSTRACT: In this paper an innovative solution leading to high performance/low-cost multi-domain T/R modules, utilizing emerging semi-conductor technologies such as GaN and SiGe, will be outlined. In particular a complete X-Band TRM MMIC chip-set based on GaN for the front-end RF functions and on SiGe multifunction chip for signal amplitude and phase control will be presented. The GaN front-end RF functions comprise state-of-the-art HPA, robust LNA and high power SPDT switch MMICs designed and fabricated by Selex Sistemi Integrati internal facilities. The SiGe multifunction Core Chip has been designed by Selex Sistemi Integrati employing a low-cost SiGe BiCMOS commercial process.
Phased Array Systems and Technology (ARRAY), 2010 IEEE International Symposium on; 11/2010
-
[show abstract]
[hide abstract]
ABSTRACT: This paper reports the performance of a two-stage X-Band MMIC GaN HPA designed for radar applications. At 20V drain voltage bias and 3dB compression point the HPA delivers more than 20W of pulsed RF power with a PAE of 35% over the 8-10.5GHz frequency range, whereas at Vds=35V the MMIC provides more than 50W and 30% of PAE, with a peak power value of 58W at 9 GHz. In order to evaluate the effective HPA power capability in a real system environment and the related thermal management issues, the HPA transient thermal response for pulsed bias conditions has been investigated by means of IR thermo-camera measurements.
Microwave Conference (EuMC), 2010 European; 10/2010
-
[show abstract]
[hide abstract]
ABSTRACT: The development of a single bias S-band MMIC HPA designed for radar T/R module applications is reported. The chip was fabricated with a low-cost 0.5μm GaAs PHEMT process and is composed of two stages, with a final stage of 29 mm gate-width periphery. The MMIC power amplifier is designed by using a zero gate bias configuration and therefore is attractive due to the size and cost reduction. In the frequency bandwidth 2.4-3.6GHz, the HPA biased at Vd = 10 V delivers an output power of 20 W @ 4 dB of gain compression, with an associated PAE of circa 28%.
Microwave Integrated Circuits Conference (EuMIC), 2010 European; 10/2010
-
[show abstract]
[hide abstract]
ABSTRACT: In this paper a first iteration X-band T/R module based on a GaN-HEMT MMIC Front-End chip-set, comprising a power amplifier, robust low-noise amplifier and power switch will be presented. Even though ultimate T/R module performance cannot be achieved with current GaN-HEMT technological maturity the impact that this technology can have at systems level in terms of performance/cost trade-off will be illustrated by means of a preliminary innovative module architecture which foresees the elimination of more traditional T/R module components such as ferrite circulator and limiter for front-end signal routing and protection.
Radar Conference, 2009. EuRAD 2009. European; 11/2009
-
[show abstract]
[hide abstract]
ABSTRACT: In this paper design, fabrication and test of three X-Band robust LNA MMICs in microstrip GaN technology are presented to better understand the key aspects of performance versus robustness trade-off for said components. In particular LNAs with different number of amplification stages, input device gate peripheries and topologies have been evaluated with the objective of achieving in the 8-11 GHz frequency range a NF better than 2.5 dB, associated gain of circa 20 dB and overdrive power survivability better than 38 dBm. On-wafer measurements of LNA performance and robustness have been carried out in order to evaluate the incident power failure mechanisms and to individuate the best design approach for optimum performance/robustness trade-off. With one of the three LNA designs a NF <; 2dB, G<sub>ass</sub> of 20 dB and P<sub>1dB</sub> > 15 dBm has been achieved in the entire 8-11 GHz bandwidth. Said MMIC can withstand a 39 dBm CW input power without any observable performance degradation.
Microwave Conference, 2009. EuMC 2009. European; 11/2009
-
[show abstract]
[hide abstract]
ABSTRACT: In this paper is reported the design, fabrication and test of a mixed-signal SiGe X-band multi-function control MMIC for phased array radar applications. Said MMIC, fabricated, with the ST-Microelectronics BiCMOS7RF SiGe technology, comprises a 5-bit phase shifter, 5-bit attenuator, SPDT switches, several gain amplifiers and a digital serial to parallel converter to reduce the number of MMIC I/O control lines. The gain amplifiers are implemented using SiGe HBTs, while phase shifter, attenuator and SPDT switches are based on CMOS transistors. The measurement results show a return loss better than 15 dB and a gain of 17 dB, equal in both RX and TX state. In RX mode the obtained noise figure is lower than 10 dB, while in TX mode the output P<sub>1 dB</sub> is higher than 12 dBm. The achieved RF performance, the low power consumption and associated low cost, make this SiGe control-chip an attractive solution for high performance/low cost Tx/Rx components for phased array radar applications.
Microwave Conference, 2009. EuMC 2009. European; 11/2009
-
[show abstract]
[hide abstract]
ABSTRACT: This paper presents the results of the development of 2-6 GHz broadband high-power amplifiers (HPA) within the 1<sup>st</sup> iteration of the European Korrigan project. The HPAs were fabricated using AlGaN/GaN high electronic mobility transistors (HEMT) and monolithic microwave integrated circuit (MMIC) technology. Two microstrip HPAs with output-stage active periphery of 4 mm and 8 mm are reported. The two-stage amplifiers were designed to be fully matched to 50 Omega input and output impedances. Based on a 0.5 mum gate-length microstrip HEMT technology, the MMICs were fabricated on a 70 mum thick SiC substrate. Under a 25 V DC bias condition the broadband amplifiers have exhibited about 18 dB small-signal gain. The 4mm-HPA delivers 10 W output power and 25% power added efficiency (PAE) in the 2-6 GHz frequency band, in continuous wave operation (CW) at Vds=25V. On the other hand, the 8mm-HPA delivers 16 W and 20% PAE in CW. In pulsed-mode, the output powers are 14 W and 25 W for the 4 mm and the 8 mm HPAs, respectively.
Microwave Integrated Circuits Conference, 2009. EuMIC 2009. European; 10/2009
-
E. Zanoni,
G. Meneghesso,
M. Meneghini,
A. Tazzoli,
N. Ronchi,
A. Stocco,
F. Zanon,
A. Chini,
G. Verzellesi, A. Cetronio,
C. Lanzieri,
M. Peroni
[show abstract]
[hide abstract]
ABSTRACT: Several groups have demonstrated nitride-based High Electron Mobility Transistors with excellent rf output power, with a constant increase in performances. However, despite the large efforts spent in the last few years, and the progress in MTTF (Mean Time To Failure) values, reliability of GaN HEMTs (High Electron Mobility Transistors) and MMICs (Millimeter Microwave Integrated Circuits) still has to be fully demonstrated, due to the continuous evolution of adopted processes and technologies, and to the lack of information concerning failure modes and mechanisms. The role of temperature in promoting GaN HEMT failure is controversial, and the factors accelerating degradation are largely unknown. This paper proposes a methodology for the analysis of failure modes and mechanisms of GaN HEMTs, based on the extensive characterization of deep levels using Deep Level Transient Spectroscopy (DLTS) and pulsed measurements, on the detailed analysis of electrical characteristics, and on comparison with two-dimensional device simulations. Results of failure analysis using various microscopy and spectroscopy techniques are presented and failure mechanisms observed at the high electric field values typical of the operation of these devices are reviewed.
Microwave Integrated Circuits Conference, 2009. EuMIC 2009. European; 10/2009
-
[show abstract]
[hide abstract]
ABSTRACT: Reverse-bias testing in AlGaN/GaN HEMTs at high (negative) gate voltage is found to induce a catastrophic increase in gate leakage current I<sub>G</sub>, with only a slight degradation of drain current I<sub>D</sub>. Electroluminescence (EL) microscopy demonstrates that leakage current injection is localized within ldquohot spotsrdquo at the gate edges, possibly corresponding to defects in the semiconductor material or at the metal-semiconductor interface. The density of ldquohot spotsrdquo increases during tests and is correlated with the increase of I<sub>G</sub> and electroluminescence intensity and with an enhancement of trapping effects such as current collapse.
IEEE Electron Device Letters 06/2009; · 2.85 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: In this paper a first iteration design, fabrication and test of a two-stage X-band MMIC HPA in micro-strip AlGaN/GaN technology is reported. With 20 V drain voltage operating bias point, at 3 dB compression point, the HPA delivers a pulsed output power ranging from 21 to 28.5 W, an associated gain from 12.9 to 16.5 dB and an associated PAE from circa 30% to 40%, over the 8-10.5 GHz frequency bandwidth. In the best performance frequency points (8.5 and 9 GHz) the HPA exhibits a saturated output power of 30 W with an associated PAE of 40%.
Wireless Technology, 2008. EuWiT 2008. European Conference on; 11/2008
-
[show abstract]
[hide abstract]
ABSTRACT: This paper presents the results obtained both by experimental measurements and numerical simulations carried out on state-of-the-art Field-Plated GaAs-based pHEMTs. The effect of field-plate length on DC and RF operation of pHEMTs will be discussed showing that the adoption of an optimal field-plate structure can significantly boost the device RF power performance, resulting in power density up to 2 W/mm measured under continuous wave RF signals at 2 GHz. The physical origin of the DC-to-RF dispersion in the fabricated devices has been associated with a hole-trap located at 0.65 eV from the valence band as obtained from current-DLTS measurements. The experimental results will also be supported and validated by numerical simulations. It will be shown that the beneficial effects arising from the adoption of the field-plate structure lie in its control on the trapped charge population responsible for the DC-to-RF dispersion mechanism.
Microwave Integrated Circuit Conference, 2008. EuMIC 2008. European; 11/2008
-
[show abstract]
[hide abstract]
ABSTRACT: This paper presents two MMIC broadband high power amplifiers of 4 mm of periphery at the output stage in the frequency band 2-6 GHz. The amplifiers are based on Al-GaN/GaN high electron mobility transistor (HEMT) technology on SiC substrate. They have been fabricated in two different european foundries: SELEX Sistemi Integrati and QINETIQ. SELEX has a gate process technology of 0.5 mum, and devices of 10times100 mum periphery in microstrip technology and QINETIQ has a gate-length of 0.25 mum, and devices of 8times125 mum in coplanar technology. The coplanar amplifier from QINETIQ has demonstrated an output power of 8 W in continuous wave at V<sub>ds</sub>=20 V which confirm model predictions. On the other hand, SELEX microstrip amplifier has a saturation power of 10 W CW at V<sub>ds</sub>=25 V and 4 GHz. This amplifier measured on-wafer in pulsed conditions exhibits a maximum power of 17 W at V<sub>ds</sub>=30 V.
Microwave Integrated Circuit Conference, 2008. EuMIC 2008. European; 11/2008
-
V. Alleva,
A. Bettidi, A. Cetronio,
M. De Dominicis,
M. Ferrari,
E. Giovine,
C. Lanzierf,
E. Limiti,
A. Megna,
M. Peroni,
P. Romaninf
[show abstract]
[hide abstract]
ABSTRACT: In this paper the design, fabrication and test of X-band and 2-18 GHz wideband high power SPDT MMIC switches in microstrip GaN technology are presented. Such switches have demonstrated state-of-the-art performances. In particular the X-band switch exhibits 1 dB insertion loss, better than 37 dB isolation and a power handling capability at 9 GHz of better than 39 dBm at 1 dB insertion loss compression point; the wideband switch has an insertion loss lower than 2.2 dB, better than 25 dB isolation and a power handling capability of better than 38 dBm in the entire bandwidth.
Microwave Integrated Circuit Conference, 2008. EuMIC 2008. European; 11/2008
-
[show abstract]
[hide abstract]
ABSTRACT: In this paper a first iteration X-band T/R module based on a GaN-HEMT MMIC front-end chip-set, comprising a power amplifier, robust low-noise amplifier and power switch will be presented. Even though ultimate T/R module performance cannot be achieved with current GaN-HEMT technological maturity the impact that this technology can have at systems level in terms of performance/cost trade-off will be illustrated by means of a preliminary innovative module architecture which foresees the elimination of more traditional T7R module components such as ferrite circulator and limiter for front-end signal routing and protection.
Radar Conference, 2008. RADAR '08. IEEE; 06/2008
-
[show abstract]
[hide abstract]
ABSTRACT: In this paper a procedure to extract temperature dependent equivalent circuits for modeling the small and large signal behavior of GaN HEMTs is presented. The technique explained in this work uses pulsed I-V measurements to obtain the temperature dependence of the parameters describing the nonlinear drain current source behavior. The equivalent circuits extracted are capable of correctly modeling the DC, small signal and large signal characteristics of GaN HEMTs devices. Simulations and measurements carried out on three transistors developed by SELEX-SI are compared over a wide range of frequencies, bias and load conditions.
Microwave Integrated Circuit Conference, 2007. EuMIC 2007. European; 11/2007
-
[show abstract]
[hide abstract]
ABSTRACT: High breakdown voltage pHEMTs have been successfully developed by implementing a field-plate (FP) structure. Devices with and without FP have been fabricated on the same wafer in order to compare the improvements induced by adopting the FP. Both kinds of devices showed little or no current dispersion under pulse measurement conditions. Moreover the off-state breakdown voltage improved from 23V, for the devices without FP, to 38V for the field-plated devices. At 4GHz an output power as high as 1.6W/mm was measured for a FP device, resulting in a 60% improvement with respect to the device without FP. The fabricated structures were also evaluated by carrying out 2D numerical simulations. Experimental results on MIS pHEMTs have been explained by means of a donor trap at the SiN/GaAs interface located at 0.18eV from the GaAs conduction band. Finally, a good agreement between experimental and simulated device characteristics was obtained
European Microwave Integrated Circuits Conference, 2006. The 1st; 10/2006
-
P. Romanini,
M. Peroni,
C. Lanzieri, A. Cetronio,
M. Calori,
A. Passaseo,
B. Poti,
A. Chini,
L. Mariucci,
A. Di Gaspare,
V. Teppati,
V. Camarchia
[show abstract]
[hide abstract]
ABSTRACT: One of the main expected benefits of AlGaN HEMT technology for microwave applications is related to the higher operating bias voltage achievable with these devices. However, various technological issues, concerning material properties and device technology must be properly tailored to fully exploit the potential of that kind of devices. In this work we report on the realization of HEMT device showing improved performance in terms of breakdown voltage, device isolation and reverse current leakage achieved by improved epilayer buffer properties and optimized field plate gate geometry. In particular the low defect density and the high resistivity obtained by using an HT-AlN crystallization layer for the growth of the GaN layer has lead to an effective 2DEG carrier concentration of 8 times 10<sup>12</sup> cm<sup>-2</sup> with related mobility of 1700cm<sup>2</sup>/Vs and corresponding devices with a very high voltage breakdown (V<sub>B</sub> > 200V), excellent active device isolation and limited reverse current leakage
European Microwave Integrated Circuits Conference, 2006. The 1st; 10/2006
-
[show abstract]
[hide abstract]
ABSTRACT: In this paper an innovative solution leading to high performance/low-cost multi-domain T/R modules, based on a "re-use core-module" technology is presented. The design concept of said technology is based on a highly integrated solution utilizing a minimum number of MMICs and robust "design-centering" to specification via the introduction of opportune control/calibration circuits and tuning-free integrating procedures. Examples of a modular C and X band T/R modules and related applications are presented together with relevant measurements and results
Microwave Symposium Digest, 2006. IEEE MTT-S International; 07/2006
-
[show abstract]
[hide abstract]
ABSTRACT: In this paper a common approach for T/R module development, in the framework of the Finmeccanica Mindsh@re initiative and the results of C and X band T/R module were presented. The roadmap identified within Finmeccanica for said technology is based on the harmonization of key enabling technologies such as the GaAs/GaN and LTCC foundries and the related design and production capability for present and future military/space qualified TRMs situated in SELEX-SI and Alenia Spazio.
Microwave Conference, 2005 European; 11/2005
-
M.G. Bisogni,
D. Bulajic, A. Cetronio,
P. Delogu,
M.E. Fantacci,
C. Lanzieri,
M. Novelli,
M. Quattrocchi,
V. Rosso,
A. Stefanini,
L. Venturelli
[show abstract]
[hide abstract]
ABSTRACT: To realize innovative instrumentation for mammography, a digital mammographic head based on several gallium arsenide detectors and on the Medipix chip (developed by the Medipix collaboration at CERN) has been designed. This device is able to perform single photon counting readout and allows a full detection efficiency at the mammographic energies. To make such detection units, industrial processes for the production of GaAs pixel detectors and for their bump-bonding to the read-out VLSI electronics have been developed by Alenia Marconi Systems (AMS S.p.A.). The detection unit is a 200 μm thick GaAs matrix of 64×64 square pixels (170 μm pitch), previously optimized and fully characterized, connected via bump bonding to the electronic chip. Specific studies were performed to develop a process that meets the requirements of low cost, high yield and high reliability for the bump bonding process of the GaAs detector to the silicon electronics. To ensure a high-quality electrical contact between the matrix detector and the silicon read out electronics a bump-bonding process has been set-up. It is based on a In evaporation process. In this work we present the technical characteristics of the bump bonding process and the results obtained in terms of bump-bonding yield and detection performance of the GaAs based detection units which have been realized and fully tested and are now ready to be implemented in the mammographic head.
Nuclear Science Symposium Conference Record, 2004 IEEE; 11/2004
