@inproceedings{RudolphMostardinhaCabraletal., author = {Rudolph, Matthias and Mostardinha, H. and Cabral, P. M. and Carvalho, N. B. and Kurpas, Paul and W{\"u}rfl, Joachim and Pinto, J. C. and Barnes, J. and Garat, F.}, title = {GaN RF Oscillator Used in Space Applications}, doi = {http://dx.doi.org/10.1109/INMMIC.2010.5480142}, language = {en} } @misc{RudolphKraemerSchmueckleetal., author = {Rudolph, Matthias and Kraemer, Tomas and Schm{\"u}ckle, Franz-Josef and W{\"u}rfl, Joachim and Tr{\"a}nkle, G{\"u}nther}, title = {InP DHBT Process in Transferred Substrate Technology with ft and fmax over 400 GHz}, language = {en} } @misc{RudolphDewitzLieroetal., author = {Rudolph, Matthias and Dewitz, Mike and Liero, Armin and Khalil, I. and Chaturvedi, Nidhi and Wipf, Christian and Bertenburg, R. M. and Miller, J. and W{\"u}rfl, Joachim and Heinrich, Wolfgang and Tr{\"a}nkle, G{\"u}nther}, title = {Highly Robust X-Band LNA with Extremely Short Recovery Time}, language = {en} } @misc{SoniaRichterBrunneretal., author = {Sonia, G. and Richter, E. and Brunner, F. and Denker, A. and Lossy, R. and Mai, M. and Lenk, Friedrich and Bundesmann, J. and Pensl, G. and Schmidt, J. and Zeimer, U. and Wang, L. and Baskar, K. and Weyers, M. and W{\"u}rfl, Joachim and Tr{\"a}nkle, G{\"u}nther}, title = {2 MeV ion irradiation effects on AlGaN/GaN HFET devices}, series = {Solid-State Electronics}, volume = {52}, journal = {Solid-State Electronics}, number = {7}, issn = {0038-1101}, pages = {1011 -- 1017}, abstract = {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.}, language = {en} } @misc{GnanapragasamRichterBrunneretal., author = {Gnanapragasam, S. and Richter, E. and Brunner, F. and Denker, A. and Lossy, R. and Mai, M. and Lenk, Friedrich and Opitz-Coutureau, J. and Pensl, G. and Schmidt, J. and Zeimer, U. and Wang, L. and Krishnan, B. and Weyers, M. and W{\"u}rfl, Joachim and Tr{\"a}nkle, G{\"u}nther}, title = {Irradiation effects on AlGaN HFET devices and GaN layers}, series = {Journal of Materials Science: Materials in Electronics}, volume = {19}, journal = {Journal of Materials Science: Materials in Electronics}, number = {1}, issn = {1573-482X}, doi = {10.1007/s10854-008-9589-1}, pages = {64 -- 67}, abstract = {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.}, language = {en} } @misc{SoniaRichterBrunneretal., author = {Sonia, G. and Richter, E. and Brunner, F. and Denker, A. and Lossy, R. and Lenk, Friedrich and Opitz-Coutureau, J. and Mai, M. and Schmidt, J. and Zeimer, U. and Wang, L. and Baskar, K. and Weyers, M. and W{\"u}rfl, Joachim and Tr{\"a}nkle, G{\"u}nther}, title = {High energy irradiation effects on AlGaN/GaN HFET devices}, series = {Semiconductor Science and Technology}, volume = {22}, journal = {Semiconductor Science and Technology}, number = {11}, issn = {0268-1242}, doi = {10.1088/0268-1242/22/11/007}, pages = {1220 -- 1224}, abstract = {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.}, language = {en} } @inproceedings{HilsenbeckBrunnerLenketal., author = {Hilsenbeck, Jochen and Brunner, F. and Lenk, Friedrich and W{\"u}rfl, Joachim}, title = {Fabrication and Electrical Performance of Oscillators in GaAs/GaInP-HBT MMIC Technology up to 40 GHz}, series = {29th International Symposium on Compound Semiconductors (ISCS), Lausanne/Switzerland, 2002}, booktitle = {29th International Symposium on Compound Semiconductors (ISCS), Lausanne/Switzerland, 2002}, publisher = {Institute of Physics Publ.}, address = {Bristol [u.a.]}, isbn = {0-7503-0942-3}, pages = {239 -- 242}, language = {en} } @inproceedings{LenkSchottHilsenbecketal., author = {Lenk, Friedrich and Schott, Matthias and Hilsenbeck, Jochen and W{\"u}rfl, Joachim and Heinrich, Wolfgang}, title = {Low phase-noise monolithic GaInP/GaAs-HBT VCO for 77 GHz}, series = {2003 IEEE MTT-S International Microwave Symposium digest, June 8 - 13, 2003, Pennsylvania Convention Center, Philadelphia, Pennsylvania, vol. 2}, booktitle = {2003 IEEE MTT-S International Microwave Symposium digest, June 8 - 13, 2003, Pennsylvania Convention Center, Philadelphia, Pennsylvania, vol. 2}, publisher = {IEEE Service Center}, address = {Piscataway, NJ}, isbn = {0-7803-7695-1}, doi = {10.1109/MWSYM.2003.1212515}, pages = {903 -- 906}, abstract = {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.}, language = {en} } @inproceedings{KuhnertLenkHilsenbecketal., author = {Kuhnert, Holger and Lenk, Friedrich and Hilsenbeck, Jochen and W{\"u}rfl, Joachim and Heinrich, Wolfgang}, title = {Low phase-noise GaInP/GaAs-HBT MMIC oscillators up to 36 GHz}, series = {2001 IEEE MTT-S International Microwave Symposium digest, May 20 - 25, 2001, Phoenix Civic Plaza, Phoenix, AZ, vol. 3}, booktitle = {2001 IEEE MTT-S International Microwave Symposium digest, May 20 - 25, 2001, Phoenix Civic Plaza, Phoenix, AZ, vol. 3}, publisher = {IEEE Service Center}, address = {Piscataway, NJ}, isbn = {0-7803-6538-0}, doi = {10.1109/MWSYM.2001.967198}, pages = {1551 -- 1554}, abstract = {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.}, language = {en} } @inproceedings{SchottKuhnertLenketal., author = {Schott, Matthias and Kuhnert, Holger and Lenk, Friedrich and Hilsenbeck, Jochen and W{\"u}rfl, Joachim and Heinrich, Wolfgang}, title = {38 GHz push-push GaAs-HBT MMIC oscillator}, series = {2002 IEEE MTT-S International Microwave Symposium digest, June 2 - 7, 2002, Washington State Convention \& Trade Center, Seattle, Washington, vol. 2}, booktitle = {2002 IEEE MTT-S International Microwave Symposium digest, June 2 - 7, 2002, Washington State Convention \& Trade Center, Seattle, Washington, vol. 2}, publisher = {IEEE Service Center}, address = {Piscataway, NJ}, isbn = {0-7803-7239-5}, doi = {10.1109/MWSYM.2002.1011761}, pages = {839 -- 842}, abstract = {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.}, language = {en} } @inproceedings{HilsenbeckLenkLossyetal., author = {Hilsenbeck, Jochen and Lenk, Friedrich and Lossy, Richard and W{\"u}rfl, Joachim and Kohler, K. and Obloh, H.}, title = {DC and microwave properties of 0.5 um AlGaN/GaN high electron mobility transistors fabricated on 2-inch process line}, series = {IEEE International Symposium on Compound Semiconductors, held in Monterey, California, 2 - 5 October 2000}, booktitle = {IEEE International Symposium on Compound Semiconductors, held in Monterey, California, 2 - 5 October 2000}, publisher = {IEEE Service Center}, address = {Piscataway, NJ}, isbn = {0-7803-6258-6}, doi = {10.1109/ISCS.2000.947181}, pages = {351 -- 356}, abstract = {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}, language = {en} } @inproceedings{HilsenbeckLenkHeinrichetal., author = {Hilsenbeck, Jochen and Lenk, Friedrich and Heinrich, Wolfgang and W{\"u}rfl, Joachim}, title = {Low phase noise MMIC VCOs for Ka-band applications with improved GaInP/GaAs-HBT technology}, series = {Gallium Arsenide Integrated Circuit (GaAs IC) Symposium, 2003, 25th Annual Technical Digest 2003, San Diego, California, November 9 - 12, 2003}, booktitle = {Gallium Arsenide Integrated Circuit (GaAs IC) Symposium, 2003, 25th Annual Technical Digest 2003, San Diego, California, November 9 - 12, 2003}, publisher = {IEEE Service Center}, address = {Piscataway, NJ}, isbn = {0-7803-7833-4}, doi = {10.1109/GAAS.2003.1252399}, pages = {223 -- 226}, abstract = {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.}, language = {en} } @inproceedings{LenkKlockenhoffMaassdorfetal., author = {Lenk, Friedrich and Klockenhoff, Harald and Maaßdorf, Andre and W{\"u}rfl, Joachim and Heinrich, Wolfgang}, title = {A 3.2 W coplanar single-device X-band amplifier with GaAs HBT}, series = {Gallium Arsenide and Other Semiconductor Application Symposium, 2005, EGAAS 2005}, booktitle = {Gallium Arsenide and Other Semiconductor Application Symposium, 2005, EGAAS 2005}, publisher = {Horizon House Publ.}, address = {London}, isbn = {88-902012-0-7}, pages = {49 -- 52}, abstract = {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.}, language = {en} } @inproceedings{RudolphKurpasBrunneretal., author = {Rudolph, Matthias and Kurpas, Paul and Brunner, F. and Doser, W. and Maaßdorf, Andre and D{\"o}rner, Ralf and Blanck, H. and Heinrich, Wolfgang and W{\"u}rfl, Joachim}, title = {Development and Characterization of GaInP/GaAs HBTs for High Voltage Operation}, language = {en} } @article{RudolphBehtashHircheetal., author = {Rudolph, Matthias and Behtash, Reza and Hirche, Klaus and W{\"u}rfl, Joachim and Heinrich, Wolfgang and Tr{\"a}nkle, G{\"u}nther}, title = {A Highly Survivable 3-7 GHz GaN Low-Noise Amplifier}, language = {en} } @misc{RudolphAchoucheKrausetal., author = {Rudolph, Matthias and Achouche, M. and Kraus, S. and Spitzbart, Th. and Kurpas, Paul and Rentner, D. and Brunner, F. and Richter, E. and Bergunde, T. and Heymann, Peter and Wolter, P. and Wittrich, H. and Weyers, M. and W{\"u}rfl, Joachim and Tr{\"a}nkle, G{\"u}nther}, title = {InGaP/GaAs Power HBTs for L-Band Applications}, language = {en} } @misc{RudolphWuerflKurpasetal., author = {Rudolph, Matthias and W{\"u}rfl, Joachim and Kurpas, Paul and Brunner, F. and Mai, M.}, title = {Degradation properties of MOVPE-grown GaInP/GaAs HBTs under combined temperatureand current stressing}, language = {en} } @misc{KraemerMelianiLenketal., author = {Kraemer, Thorsten and Meliani, Chafik and Lenk, Friedrich and W{\"u}rfl, Joachim and Tr{\"a}nkle, G{\"u}nther}, title = {Transferred substrate DHBT of ft = 410 GHz and fmax = 480 GHz for traveling wave amplifiers}, series = {Indium Phosphide and Related Materials, 2008, IPRM 2008, 20th International Conference, Versailles, France, 25 - 29 May 2008}, journal = {Indium Phosphide and Related Materials, 2008, IPRM 2008, 20th International Conference, Versailles, France, 25 - 29 May 2008}, isbn = {978-1-4244-2258-6}, doi = {10.1109/ICIPRM.2008.4702999}, pages = {1 -- 3}, abstract = {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.}, language = {en} } @misc{KraemerLenkMaassdorfetal., author = {Kraemer, Thorsten and Lenk, Friedrich and Maaßdorf, Andre and W{\"u}rfl, Joachim and Tr{\"a}nkle, G{\"u}nther}, title = {High Yield Transferred Substrate InP DHBT}, series = {Indium Phosphide \& Related Materials, 2007, IPRM '07, IEEE 19th International Conference, Matsue, Japan, 14 - 18 May 2007}, journal = {Indium Phosphide \& Related Materials, 2007, IPRM '07, IEEE 19th International Conference, Matsue, Japan, 14 - 18 May 2007}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {1-4244-0875-X}, doi = {10.1109/ICIPRM.2007.381210}, pages = {407 -- 408}, abstract = {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.}, language = {en} } @article{RudolphBehtashDoerneretal., author = {Rudolph, Matthias and Behtash, Reza and D{\"o}rner, Ralf and Hirche, Klaus and Wurfl, Joachim and Heinrich, Wolfgang and Tr{\"a}nkle, G{\"u}nther}, title = {Analysis of the Survivability of GaN Low-Noise Amplifiers}, language = {en} }