@misc{GerlichWeger, author = {Gerlich, Stefan and Weger, Peter}, title = {A Narrow-band 8.7 GHz SiGe HBT LNA with a Passive Frequency Selective Feedback}, series = {Frequenz}, volume = {66}, journal = {Frequenz}, number = {7-8}, issn = {0016-1136}, doi = {10.1515/freq-2012-0037}, pages = {183 -- 188}, abstract = {This paper presents a low noise amplifier (LNA) with differential output using a passive frequency selective feedback. The introduced feedback stabilizes the amplifier at lower frequencies and improves the gain in the desired frequency band. The LNA consists of two stages. Additionally, a buffer at the output is added for measurements. The amplifier was implemented in a 0.35 μm SiGe technology. For measurements the LNA was bonded to a substrate. A peak gain of 28.1 dB and a minimum noise figure of 2.2 dB at a supply voltage of 3 V were achieved.}, language = {en} } @misc{GerlichWeger, author = {Gerlich, Stefan and Weger, Peter}, title = {Highly Efficient Packaged 11-13 GHz Power Amplifier in SiGe-Technology With 37.3\% of PAE}, series = {IEEE Microwave and Wireless Components Letters}, volume = {23}, journal = {IEEE Microwave and Wireless Components Letters}, number = {10}, issn = {1531-1309}, doi = {10.1109/LMWC.2013.2278285}, pages = {539 -- 541}, abstract = {A power amplifier for a frequency range of 11-13 GHz that is incorporated in 0.35 μm SiGe-technology is presented in this letter. The two-stage push-pull amplifier uses monolithically integrated transformers for input and interstage matching and a monolithically integrated modified LC-balun as an output-matching network. For stabilization purposes and gain improvement in the operating frequency range a passive frequency selective feedback in parallel to the base-collector was introduced. The power amplifier is mounted on a 7 × 7 mm VQFN package. From a single 1.8 V voltage supply, the amplifier has a power-added efficiency of greater than 30\% from 11.2 to 13 GHz with a maximum of 37.3\% at 12.5 GHz. The maximum output power is 23.4 dBm (saturation), as measured in the continuous mode.}, language = {en} } @misc{TomazGerlichRudolphetal., author = {Tomaz, Antonio and Gerlich, Stefan and Rudolph, Matthias and Andrei, Cristina}, title = {A Novel System for Recovery Time Measurements of GaN-Based Low-Noise Amplifiers}, series = {2022 14th German Microwave Conference (GeMiC), Ulm, 16-18 May 2022}, journal = {2022 14th German Microwave Conference (GeMiC), Ulm, 16-18 May 2022}, publisher = {IEEE}, isbn = {978-3-9820397-2-5}, issn = {2167-8022}, pages = {65 -- 68}, abstract = {A novel setup allowing for recovery time measurement of robust GaN LNA is presented in this paper. The setup is based on an PNA-X vector network analyzer and allows for the characterization of the LNA's small-signal gain, while it also monitors overdrive pulse power and reflected pulse power. The system setup and operation is shown in detail. As an example, two different GaN LNAs were measured in order to validate the test setup.}, language = {en} } @misc{KauleAndreiGerlichetal., author = {Kaule, Evelyne and Andrei, Cristina and Gerlich, Stefan and D{\"o}rner, Ralf and Rudolph, Matthias}, title = {Limiting the Output Power of Rugged GaN LNAs}, series = {14th European Microwave Integrated Circuits Conference (EuMIC)}, journal = {14th European Microwave Integrated Circuits Conference (EuMIC)}, address = {Paris, France}, isbn = {978-2-87487-056-9}, doi = {10.23919/EuMIC.2019.8909653}, pages = {240 -- 242}, abstract = {Rugged GaN HEMT low-noise amplifiers are well established, but the common concept of achieving ruggedness by applying the gate supply voltage through a high ohmic resistance might not be sufficient in addition to control the maximum output power. This paper shifts the focus to the protection of subsequent stages and proposes a circuit concept based on an output attenuator and an adaptive drain supply. It is shown that the concept implementation provides an attenuation of up to 28dB under input overdrive condition while leaving small-signal noise Figure unaffected.}, language = {en} } @misc{KauleAndreiGerlichetal., author = {Kaule, Evelyne and Andrei, Cristina and Gerlich, Stefan and D{\"o}rner, Ralf and Rudolph, Matthias}, title = {Limiting the Output Power of Rugged GaN LNAs}, series = {Proceedings of 49th European Microwave Conference (EuMC)}, journal = {Proceedings of 49th European Microwave Conference (EuMC)}, address = {Paris, France}, isbn = {978-2-87487-055-2}, doi = {10.23919/EuMC.2019.8910675}, pages = {794 -- 796}, abstract = {Rugged GaN HEMT low-noise amplifiers are well established, but the common concept of achieving ruggedness by applying the gate supply voltage through a high ohmic resistance might not be sufficient in addition to control the maximum output power. This paper shifts the focus to the protection of subsequent stages and proposes a circuit concept based on an output attenuator and an adaptive drain supply. It is shown that the concept implementation provides an attenuation of up to 28 dB under input overdrive condition while leaving small-signal noise figure unaffected.}, language = {en} } @phdthesis{Gerlich, author = {Gerlich, Stefan}, title = {Fully monolithically integrated X-Band amplifiers with frequency selective feedback}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-39255}, language = {en} }