TY - CHAP A1 - Schott, Matthias A1 - Lenk, Friedrich A1 - Heymann, Peter T1 - On the load-pull effect in MMIC oscillator measurements T2 - 33rd European Microwave Conference, 7 - 9th October 2003, ICM, Munich, Germany, Vol. 1 N2 - Low phase-noise MMIC oscillators are key components for microwave and nun-wave systems. As a consequence, phase-noise measurements of these circuits have become a subject of growing interest and importance. This paper demonstrates that MMIC oscillator circuits with their relatively low Q factors are prone to specific measurement errors. Caused by a load-pull effect, the measurement system can become part of the oscillator, which yields phase-noise data significantly below reality. Special care has to be taken in order to avoid such phenomena. Y1 - 2003 SN - 1-58053-834-7 U6 - https://doi.org/10.1109/EUMC.2003.1262295 SP - 367 EP - 370 PB - London CY - Korizon House Publ. ER - TY - CHAP A1 - Lenk, Friedrich A1 - Schott, Matthias A1 - Heinrich, Wolfgang T1 - Modeling and Measurement of Phase Noise in GaAs HBT Ka-Band Oscillators T2 - 31st European Microwave Conference, 2001, 24 - 26 Sept. 2001 N2 - Accurate oscillator phase-noise simulation is a key problem in MMIC design, which is not solved satisfactory so far and needs further investigation. In this paper, a Ka-band MMIC oscillator with GaInP/GaAs HBT and on-chip resonator is treated as an example. Measured phase noise reaches -90 dBc/Hz and below at 100 kHz offset. To evaluate phase-noise prediction, the circuit is simulated using different commercial simulation tools and HBT models. Considerable differences in simulation results are observed. Y1 - 2001 U6 - https://doi.org/10.1109/EUMA.2001.339168 SP - 1 EP - 4 PB - Microwave Engineering Europe CY - London 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 - 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 - Lenk, Friedrich A1 - Schott, Matthias A1 - Hilsenbeck, Jochen A1 - Heinrich, Wolfgang T1 - Optimizing MMIC reflection-type oscillators T2 - 2004 IEEE MTT-S International Microwave Symposium digest, June 6 - 11, 2004, Fort Worth Convention Center, Fort Worth, Texas, vol. 3 N2 - In this paper, optimization of the loaded quality factor QL for reflection-type HBT oscillator is investigated. Main result is an optimum relation between the S parameter phases at the three transistor ports. To support this finding, a 35.5 GHz MMIC VCO phase noise better than -85 dBc/Hz at 100 kHz offset frequency is demonstrated. Y1 - 2004 SN - 0-7803-8331-1 U6 - https://doi.org/10.1109/MWSYM.2004.1338816 SP - 1341 EP - 1344 PB - IEEE Service Center CY - Piscataway, NJ ER - TY - CHAP A1 - Schott, Matthias A1 - Lenk, Friedrich A1 - Meliani, Chafik A1 - Heinrich, Wolfgang T1 - Low phase noise X-band push-push oscillator with frequency divider T2 - 2005 IEEE MTT-S International Microwave Symposium, June 12 - 17, 2005, Long Beach, CA N2 - A MMIC Colpitts oscillator in push-push configuration with integrated frequency divider using InGaP/GaAs HBTs is presented. The output is taken from the second harmonic port while the fundamental signal is fed to a frequency divider by two thus providing a reference signal at one quarter of the output frequency. The MMIC VCO reaches state-of-the-art phase-noise performance in X-band down to -120dBc/Hz at 1MHz offset frequency at high output power and a tuning range of 4%. Y1 - 2005 SN - 0-7803-8845-3 U6 - https://doi.org/10.1109/MWSYM.2005.1516986 PB - IEEE Operations Center CY - Piscataway, NJ ER - TY - GEN A1 - Lenk, Friedrich A1 - Schott, Matthias A1 - Hilsenbeck, Jochen A1 - Heinrich, Wolfgang T1 - A new design approach for low phase-noise reflection-type MMIC oscillators T2 - IEEE transactions on microwave theory and techniques N2 - In this paper, optimization of the loaded quality factor QL for reflection-type heterojunction bipolar transistor (HBT) oscillators is investigated. The main result is an optimum relation between the S-parameter phases at the three transistor ports. A new design strategy for this type of oscillator is proposed. The analysis is verified by comparing several Ka-band monolithic-microwave integrated-circuit oscillators in GaAs HBT technology with different resonators. The measured loaded QL values correspond to the measured phase noise of the circuits. At an oscillation frequency of 33 GHz, an excellent phase noise of -87 dBc/Hz at 100-kHz offset frequency is achieved over the whole tuning range. Y1 - 2004 U6 - https://doi.org/10.1109/TMTT.2004.837319 SN - 0018-9480 VL - 52 IS - 12 SP - 2725 EP - 2731 ER - TY - GEN A1 - Kiene, Marvin A1 - Schott, Matthias A1 - Martin-Creuzburg, Dominik A1 - Laforsch, Christian T1 - Food quantity and quality modulates inducible defenses in a common predator–prey system T2 - Limnology and Oceanography KW - Zooplankton Y1 - 2024 U6 - https://doi.org/10.1002/lno.12595 SN - 1939-5590 SN - 0024-3590 VL - 69 IS - 7 SP - 1546 ER -