TY - CHAP A1 - Rudolph, Matthias A1 - Mostardinha, H. A1 - Cabral, P. M. A1 - Carvalho, N. B. A1 - Kurpas, Paul A1 - Würfl, Joachim A1 - Pinto, J. C. A1 - Barnes, J. A1 - Garat, F. T1 - GaN RF Oscillator Used in Space Applications Y1 - 2010 U6 - https://doi.org/http://dx.doi.org/10.1109/INMMIC.2010.5480142 ER - TY - GEN A1 - Rudolph, Matthias A1 - Kraemer, Tomas A1 - Schmückle, Franz-Josef A1 - Würfl, Joachim A1 - Tränkle, Günther T1 - InP DHBT Process in Transferred Substrate Technology with ft and fmax over 400 GHz Y1 - 2009 ER - TY - GEN A1 - Rudolph, Matthias A1 - Dewitz, Mike A1 - Liero, Armin A1 - Khalil, I. A1 - Chaturvedi, Nidhi A1 - Wipf, Christian A1 - Bertenburg, R. M. A1 - Miller, J. A1 - Würfl, Joachim A1 - Heinrich, Wolfgang A1 - Tränkle, Günther T1 - Highly Robust X-Band LNA with Extremely Short Recovery Time Y1 - 2009 ER - TY - GEN A1 - Sonia, G. A1 - Richter, E. A1 - Brunner, F. A1 - Denker, A. A1 - Lossy, R. A1 - Mai, M. A1 - Lenk, Friedrich A1 - Bundesmann, J. A1 - Pensl, G. A1 - Schmidt, J. A1 - Zeimer, U. A1 - Wang, L. A1 - Baskar, K. A1 - Weyers, M. A1 - Würfl, Joachim A1 - Tränkle, Günther T1 - 2 MeV ion irradiation effects on AlGaN/GaN HFET devices T2 - Solid-State Electronics N2 - AlGaN/GaN heterostructure field effect transistors (HFETs) were irradiated with 2 MeV protons, carbon, oxygen, iron and krypton ions with fluences ranging from 1 × 109 cm−2 to 1 × 1013 cm−2. DC, pulsed I–V characteristics, loadpull and S-parameters of the AlGaN HFET devices were measured before and after irradiation. In parallel, a thick GaN reference layer was also irradiated with the same ions and was characterized by X-ray diffraction, photoluminescence, Hall measurements before and after irradiation. Small changes in the device performance were observed after irradiation with carbon and oxygen at a fluence of 5 × 1010 cm−2. Remarkable changes in device characteristics were seen at a fluence of 1 × 1012 cm−2 for carbon, oxygen, iron and krypton irradiation. Similarly, remarkable changes were also observed in the GaN layer for irradiations with fluence of 1 × 1012 cm−2. The results found on devices and on the GaN layer were compared and correlated. Y1 - 2008 UR - http://www.sciencedirect.com/science/article/pii/S0038110108000671 SN - 0038-1101 VL - 52 IS - 7 SP - 1011 EP - 1017 ER - TY - GEN A1 - Gnanapragasam, S. A1 - Richter, E. A1 - Brunner, F. A1 - Denker, A. A1 - Lossy, R. A1 - Mai, M. A1 - Lenk, Friedrich A1 - Opitz-Coutureau, J. A1 - Pensl, G. A1 - Schmidt, J. A1 - Zeimer, U. A1 - Wang, L. A1 - Krishnan, B. A1 - Weyers, M. A1 - Würfl, Joachim A1 - Tränkle, Günther T1 - Irradiation effects on AlGaN HFET devices and GaN layers T2 - Journal of Materials Science: Materials in Electronics N2 - AlGaN/GaN heterostructure field effect transistors (HFETs) were irradiated with protons as well as carbon, oxygen, iron and krypton ions of high (68 and 120 MeV) and low (2 MeV) energy with fluences in the range from 1x107 to 1x1013 cm-2. High energy irradiation with protons, carbon and oxygen produced no degradation in devices while krypton irradiation at the fluence of 1x1010 cm-2 resulted in a small reduction of 2% in the transconductance. Similarly, for GaN samples irradiated with protons, carbon and oxygen at high energy no changes were seen by XRD, PL and Hall effect, while changes in lattice constant and a reduction in PL intensity were observed after irradiation with high energy krypton. Low energy irradiation with carbon and oxygen at a fluence of 5x1010 cm-2 results in small change in the device performance while remarkable changes in device characteristics are seen at a fluence of 1x1012 cm-2 for carbon, oxygen, iron and krypton irradiation. Similarly changes are also observed by XRD, PL and Hall effect for the thick GaN layer irradiated at the fluence of 1x1012 cm-2. The device results and GaN layer properties are strongly correlated. Y1 - 2008 U6 - https://doi.org/10.1007/s10854-008-9589-1 SN - 1573-482X VL - 19 IS - 1 SP - 64 EP - 67 ER - TY - GEN A1 - Sonia, G. A1 - Richter, E. A1 - Brunner, F. A1 - Denker, A. A1 - Lossy, R. A1 - Lenk, Friedrich A1 - Opitz-Coutureau, J. A1 - Mai, M. A1 - Schmidt, J. A1 - Zeimer, U. A1 - Wang, L. A1 - Baskar, K. A1 - Weyers, M. A1 - Würfl, Joachim A1 - Tränkle, Günther T1 - High energy irradiation effects on AlGaN/GaN HFET devices T2 - Semiconductor Science and Technology N2 - The effect of proton, carbon, oxygen and krypton irradiation on AlGaN HFET devices has been studied. Irradiation was performed at 68 and 120 MeV with fluences in the range from 1 × 10^7 to 1 × 10^13 cm2 . Before and after irradiation, dc and pulsed I – V characteristics, loadpull and S -parameters of the AlGaN HFET devices were measured. A thick GaN reference layer was characterized by x-ray diffraction, photoluminescence and Hall measurements before and after irradiation. Proton, carbon and oxygen irradiation show no degradation in devices while krypton irradiation shows a small change at a fluence of 1 × 10 10 cm2 in the device characteristics. The device results are correlated with the thick GaN results. Y1 - 2007 U6 - https://doi.org/10.1088/0268-1242/22/11/007 SN - 0268-1242 VL - 22 IS - 11 SP - 1220 EP - 1224 ER - TY - CHAP A1 - Hilsenbeck, Jochen A1 - Brunner, F. A1 - Lenk, Friedrich A1 - Würfl, Joachim T1 - Fabrication and Electrical Performance of Oscillators in GaAs/GaInP-HBT MMIC Technology up to 40 GHz T2 - 29th International Symposium on Compound Semiconductors (ISCS), Lausanne/Switzerland, 2002 Y1 - 2002 SN - 0-7503-0942-3 SN - 978-07503-0942-4 SP - 239 EP - 242 PB - Institute of Physics Publ. CY - Bristol [u.a.] ER - TY - CHAP A1 - Lenk, Friedrich A1 - Schott, Matthias A1 - Hilsenbeck, Jochen A1 - Würfl, Joachim A1 - Heinrich, Wolfgang T1 - Low phase-noise monolithic GaInP/GaAs-HBT VCO for 77 GHz T2 - 2003 IEEE MTT-S International Microwave Symposium digest, June 8 - 13, 2003, Pennsylvania Convention Center, Philadelphia, Pennsylvania, vol. 2 N2 - Coplanar W-band push-push VCO MMICs using GaInP/GaAs HBTs are presented. One circuit operates at 77 GHz with phase noise of -92 dBc/Hz at 1 MHz offset. To our knowledge this is the first fully monolithic W-band VCO with phase noise better than -90 dBc/Hz. A second version with two varactor diodes yields an almost threefold relative tuning bandwidth. Y1 - 2003 SN - 0-7803-7695-1 U6 - https://doi.org/10.1109/MWSYM.2003.1212515 SP - 903 EP - 906 PB - IEEE Service Center CY - Piscataway, NJ ER - TY - CHAP A1 - Kuhnert, Holger A1 - Lenk, Friedrich A1 - Hilsenbeck, Jochen A1 - Würfl, Joachim A1 - Heinrich, Wolfgang T1 - Low phase-noise GaInP/GaAs-HBT MMIC oscillators up to 36 GHz T2 - 2001 IEEE MTT-S International Microwave Symposium digest, May 20 - 25, 2001, Phoenix Civic Plaza, Phoenix, AZ, vol. 3 N2 - Monolithic coplanar 18 and 36 GHz oscillators with GaInP/GaAs-HBTs and on-chip resonators are presented. Measured phase-noise reaches -93 dBc/Hz and -91 dBc/Hz at 100 kHz offset for 18 and 36 GHz, respectively. These values demonstrate that GaAs-HBT oscillators yield a phase-noise performance comparable to SiGe-HBTs, with the potential for higher frequencies. Y1 - 2001 SN - 0-7803-6538-0 U6 - https://doi.org/10.1109/MWSYM.2001.967198 SP - 1551 EP - 1554 PB - IEEE Service Center CY - Piscataway, NJ ER - TY - CHAP A1 - Schott, Matthias A1 - Kuhnert, Holger A1 - Lenk, Friedrich A1 - Hilsenbeck, Jochen A1 - Würfl, Joachim A1 - Heinrich, Wolfgang T1 - 38 GHz push-push GaAs-HBT MMIC oscillator T2 - 2002 IEEE MTT-S International Microwave Symposium digest, June 2 - 7, 2002, Washington State Convention & Trade Center, Seattle, Washington, vol. 2 N2 - Two differential coplanar MMIC HBT oscillators are presented, a fixed frequency and a VCO version. They provide single-ended output at the second harmonic at 38 GHz as well as differential output at 19 GHz. The oscillators show excellent phase noise performance, the fixed-frequency type reaches -95 dBc/Hz at the fundamental frequency and -89 dBc/Hz at the second harmonic, at 100 kHz offset. Y1 - 2002 SN - 0-7803-7239-5 U6 - https://doi.org/10.1109/MWSYM.2002.1011761 SP - 839 EP - 842 PB - IEEE Service Center CY - Piscataway, NJ ER - TY - CHAP A1 - Hilsenbeck, Jochen A1 - Lenk, Friedrich A1 - Lossy, Richard A1 - Würfl, Joachim A1 - Kohler, K. A1 - Obloh, H. T1 - DC and microwave properties of 0.5 um AlGaN/GaN high electron mobility transistors fabricated on 2-inch process line T2 - IEEE International Symposium on Compound Semiconductors, held in Monterey, California, 2 - 5 October 2000 N2 - DC and RF characteristics of AlGaN/GaN HEMTs processed by 2-inch stepper lithography are presented. The devices, grown by MOVPE on 2" sapphire wafers consist of: GaN buffer, Al0.25Ga0.75 N spacer, doped Al0.25Ga0.75N supply layer, Al0.25Ga0.75N barrier, GaN cap. Refractory source and gate contacts along with mesa isolation and air bridge technology are applied. Typical values for maximum saturation current, transconductance and pinch-off voltage are: 616 m/A/mm, 203 mS/mm, -3.5 V with very good homogeneity across 2". The cut off frequencies fT and fmax are 24 and 54 GHz respectively. A standard small signal equivalent circuit model exactly describes DC- and microwave properties Y1 - 2000 SN - 0-7803-6258-6 U6 - https://doi.org/10.1109/ISCS.2000.947181 SP - 351 EP - 356 PB - IEEE Service Center CY - Piscataway, NJ ER - TY - CHAP A1 - Hilsenbeck, Jochen A1 - Lenk, Friedrich A1 - Heinrich, Wolfgang A1 - Würfl, Joachim T1 - Low phase noise MMIC VCOs for Ka-band applications with improved GaInP/GaAs-HBT technology T2 - Gallium Arsenide Integrated Circuit (GaAs IC) Symposium, 2003, 25th Annual Technical Digest 2003, San Diego, California, November 9 - 12, 2003 N2 - We report on the technology and performance of fully monolithic coplanar voltage-controlled oscillators (VCOs) with GaInP/GaAs-HBTs as the active devices. With our optimized HBT process, the parasitic base resistance R/sub B/ and extrinsic base-collector capacitance C/sub EX/ are significantly reduced. In this way, the maximum frequency of oscillation F/sub max/ is increased from 100 to 170 GHz. This allows us to realize fundamental 38 GHz-VCOs with very low phase noise. At an oscillation frequency F/sub res/=34.2/spl plusmn/0.2 GHz, the VCO reaches phase noise levels of -87 dBc/Hz @ 100 kHz and -108 dBc/Hz @ 1 MHz offset frequency, respectively. To our knowledge, these phase noise values are the lowest GaAs data for Ka-band applications reported so far. Y1 - 2003 SN - 0-7803-7833-4 U6 - https://doi.org/10.1109/GAAS.2003.1252399 SP - 223 EP - 226 PB - IEEE Service Center CY - Piscataway, NJ ER - TY - CHAP A1 - Lenk, Friedrich A1 - Klockenhoff, Harald A1 - Maaßdorf, Andre A1 - Würfl, Joachim A1 - Heinrich, Wolfgang T1 - A 3.2 W coplanar single-device X-band amplifier with GaAs HBT T2 - Gallium Arsenide and Other Semiconductor Application Symposium, 2005, EGAAS 2005 N2 - High-power GaInP/GaAs HBTs with high breakdown voltage for X-band applications are presented. To demonstrate the capabilities of these devices, a simple monolithic amplifier is realized. For a single 12-finger device with 2/spl times/70 /spl mu/m/sup 2/ emitter finger size, an output power of 3.2 W at 9 GHz with 47% PAE is achieved. Y1 - 2005 UR - http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=1637147 SN - 88-902012-0-7 SP - 49 EP - 52 PB - Horizon House Publ. CY - London ER - TY - CHAP A1 - Rudolph, Matthias A1 - Kurpas, Paul A1 - Brunner, F. A1 - Doser, W. A1 - Maaßdorf, Andre A1 - Dörner, Ralf A1 - Blanck, H. A1 - Heinrich, Wolfgang A1 - Würfl, Joachim T1 - Development and Characterization of GaInP/GaAs HBTs for High Voltage Operation Y1 - 2001 ER - TY - JOUR A1 - Rudolph, Matthias A1 - Behtash, Reza A1 - Hirche, Klaus A1 - Würfl, Joachim A1 - Heinrich, Wolfgang A1 - Tränkle, Günther T1 - A Highly Survivable 3-7 GHz GaN Low-Noise Amplifier Y1 - 2006 ER - TY - GEN A1 - Rudolph, Matthias A1 - Achouche, M. A1 - Kraus, S. A1 - Spitzbart, Th. A1 - Kurpas, Paul A1 - Rentner, D. A1 - Brunner, F. A1 - Richter, E. A1 - Bergunde, T. A1 - Heymann, Peter A1 - Wolter, P. A1 - Wittrich, H. A1 - Weyers, M. A1 - Würfl, Joachim A1 - Tränkle, Günther T1 - InGaP/GaAs Power HBTs for L-Band Applications Y1 - 1999 ER - TY - GEN A1 - Rudolph, Matthias A1 - Würfl, Joachim A1 - Kurpas, Paul A1 - Brunner, F. A1 - Mai, M. T1 - Degradation properties of MOVPE-grown GaInP/GaAs HBTs under combined temperatureand current stressing Y1 - 2001 ER - TY - GEN A1 - Kraemer, Thorsten A1 - Meliani, Chafik A1 - Lenk, Friedrich A1 - Würfl, Joachim A1 - Tränkle, Günther T1 - Transferred substrate DHBT of ft = 410 GHz and fmax = 480 GHz for traveling wave amplifiers T2 - Indium Phosphide and Related Materials, 2008, IPRM 2008, 20th International Conference, Versailles, France, 25 - 29 May 2008 N2 - We report a MMIC process in transferred substrate technology. The transistors of 0.8 times 5 mum2 emitter size feature ft = 410 GHz and fmax = 480 GHz at BVceo = 5.5 V. Traveling wave amplifiers of 12 dB broadband gain up to fc = 70 GHz were realized. Y1 - 2008 SN - 978-1-4244-2258-6 SN - 978-1-4244-2259-3 U6 - https://doi.org/10.1109/ICIPRM.2008.4702999 SP - 1 EP - 3 ER - TY - GEN A1 - Kraemer, Thorsten A1 - Lenk, Friedrich A1 - Maaßdorf, Andre A1 - Würfl, Joachim A1 - Tränkle, Günther T1 - High Yield Transferred Substrate InP DHBT T2 - Indium Phosphide & Related Materials, 2007, IPRM '07, IEEE 19th International Conference, Matsue, Japan, 14 - 18 May 2007 N2 - A transferred substrate InP DHBT of 0.8 mum emitter width was developed. The transistors featured high yield and homogeneous device characteristics over the three inch wafer, with an average of ft = 300 GHz plusmn 3%SD, fmax = 250 GHz plusmn 5%SD at a breakdown voltage of BVceo = 6 V. Y1 - 2007 SN - 1-4244-0875-X U6 - https://doi.org/10.1109/ICIPRM.2007.381210 SP - 407 EP - 408 PB - IEEE CY - Piscataway, NJ ER - TY - JOUR A1 - Rudolph, Matthias A1 - Behtash, Reza A1 - Dörner, Ralf A1 - Hirche, Klaus A1 - Wurfl, Joachim A1 - Heinrich, Wolfgang A1 - Tränkle, Günther T1 - Analysis of the Survivability of GaN Low-Noise Amplifiers Y1 - 2007 ER -