Dr.-Ing. Johannes Wagner

I studied electrical engineering at the University of Ulm, where I received my B.Sc. degree in 2012 and my M.Sc. degree in 2015. During my Bachelor I focused on material science for electrical devices resulting in the Bachelor thesis with the title "Herstellung von Probenträgern für Hallmessungen an Graphen in-situ in einem Transmissionselektronenmikroskop". My master was focused on microelectronics. I finished it with the Master thesis titled "Model Extension of an Online Tool for the Heuristic Design of CT Sigma-Delta Modulators".

In September 2015 I began my work at the University of Ulm and received the Dr.-Ing. degree under the supervision of Professor Dr.-Ing. Maurits Ortmanns in May 2021. My research area is the system-level modeling and optimization of Sigma-Delta ADCs.

Publikationen

2023

26.
Kässer, P.; Wagner, J.; Ismail, O.; Driemeyer, B.; Ortmanns, M.
Quantizer Gain in Incremental Delta-Sigma ADCs
30th IEEE International Conference on Electronics, Circuits and Systems (ICECS), Istanbul, Turkiye, pp. 1-4
December 2023
DOI:10.1109/ICECS58634.2023.10382904
25.
Kässer, P.; Ismail, O.; Wagner, J.; Fischer, R.; Ortmanns, M.
Frequency-Domain Analysis of Reconfigured Incremental ΔΣ ADCs on the Example of the Exponential Phase
IEEE Transactions on Circuits and Systems I: Regular Papers
September 2023
DOI:10.1109/TCSI.2023.3310655
24.
Kässer, P.; Ismail, O.; Rudorf, C.; Wagner, J.; Ortmanns, M.
Linear-Exponential I-DS ADCs: Analysis, Limitations and Higher Order
IEEE International Symposium on Circuits and Systems (ISCAS), Monterey, CA, USA, pp. 1-5
May 2023
DOI:10.1109/ISCAS46773.2023.10182215

2022

23.
Wagner, J.; Mokhtar, M. A.; Ortmanns, M.
Automated Design of Sigma-Delta Modulators with FIR Feedback
IEEE International Symposium on Circuits and Systems (ISCAS), Austin, USA
June 2022

2021

22.
Wagner, J.; Miki, T.; Ortmanns, M.
Compensation of Finite GBW in CT Baddpass SDMs Based on Single-OpAmp Resonators with Positive-Feedback
IEEE 64th International Midwest Symposium on Circuits and Systems (MWSCAS)
August 2021
21.
Pietzko, M.; Wagner, J.; Abdelaal, A.; Kauffman, J. G.; Ortmanns, M.
Influence of Excess Loop Delay on the STF of Continuous-Time Delta-Sigma Modulators
IEEE International Symposium on Circuits and Systems (ISCAS), Daegu, Korea (Online)
May 2021

2020

20.
Wagner, J.; Vogelmann, P.; Ortmanns, M.
An Automated Design Environment for CT Incremental Sigma-Delta ADCs
27th IEEE International Conference on Electronics, Circuits and Systems (ICECS)
November 2020
19.
Vogelmann, P.; Wagner, J.; Ortmanns, M.
A 14b, Twofold Time-Interleaved Incremental ΔΣ ADC Using Hardware Sharing
IEEE Transactions on Circuits and Systems I: Regular Papers
July 2020
DOI:10.1109/TCSI.2020.3011362
18.
Wagner, J.; Vogelmann, P.; Ortmanns, M.
Performance Evaluation of Incremental Sigma-Delta ADCs Based on their NTF
IEEE Transactions on Circuits and Systems—II: Express Briefs (Early Access)
March 2020

2019

17.
Wagner, J.; Vogelmann, P.; Ortmanns, M.
On the Signal Filtering Property of CT Incremental Sigma-Delta ADCs
IEEE Transactions on Circuits and Systems—II: Express Briefs
November 2019
16.
Mokhtar, M. A.; Vogelmann, P.; Wagner, J.; Ortmanns, M.
Incremental Sturdy-MASH Sigma-Delta Modulator with Reduced Sensitivity to DAC Mismatch
IEEE International Symposium on Circuits and Systems (ISCAS), Sapporo, Japan
May 2019
15.
Luo, Y.; Jain, A.; Wagner, J.; Ortmanns, M.
Input Referred Comparator Noise in SAR ADCs
IEEE Transactions on Circuits and Systems II: Express Briefs, vol. 66, no. 5, pp. 718-722
May 2019
DOI:10.1109/TCSII.2019.2909429
14.
Vogelmann, P.; Wagner, J.; Haas, M.; Ortmanns, M.
A Dynamic Power Reduction Technique for Incremental ΔΣ Modulators
IEEE Journal of Solid-State Circuits
January 2019

2018

13.
Wagner, J.; Vogelmann, P.; Ortmanns, M.
On the Optimization of DT Incremental Sigma-Delta Modulators in Combination with CoI Reconstruction Filters
2nd New Generation of Circuits & Systems Conference (NGCAS 2018), Valetta, Malta
November 2018
12.
Wagner, J.; Vogel, F.; Kuhm, F.; Ortmanns, M.
Automated Synthesis of Subsampling CT Bandpass Sigma-Delta Modulators with Non-Idealities
2nd New Generation of Circuits & Systems Conference (NGCAS 2018), Valetta, Malta
November 2018
11.
Wagner, J.; Ortmanns, M.; de la Rosa, J. M.
Man or Machine — Design Automation of Delta-Sigma Modulators
IEEE International Symposium on Circuits and Systems (ISCAS), Florence, Italy, pp. 1-5
May 2018
10.
Vogelmann, P.; Wagner, J.; Hänsler, A.; Ortmanns, M.
On Incremental ∆Σ Modulators with SNR and SQNR Enhancement by Recuperation Phase
IEEE International Symposium on Circuits and Systems (ISCAS), Florence, Italy
May 2018
File:pdfhttps://www.uni-ulm.de/fileadmin/website_uni_ulm/iui.inst.010/downloads/Vogelmann_ISCAS_2018-05.pdf
9.
Vogelmann, P.; Wagner, J.; Hänsler, A.; Ortmanns, M.
Improved SQNR and MSA in Incremental ΔΣ Modulators by Using a Recuperation Phase
IEEE Transactions on Circuits and Systems—II: Express Briefs, Vol. 65, No. 5
May 2018

2017

8.
Wagner, J.; Chi, J.; Ortmanns, M.
Designing CT Bandpass Sigma-Delta Modulators with Arbitrary STF Shapes
IEEE International Symposium on Circuits and Systems (ISCAS 2017), Baltimore, USA
May 2017
7.
Chi, J.; Wagner, J.; Anders, J.; Ortmanns, M.
Digital Interferer Suppression and Jitter Reduction in Continuous-Time Bandpass Sigma Delta Modulators
IEEE International Symposium on Circuits and Systems (ISCAS 2017), Baltimore, USA
May 2017

2016

6.
Wagner, J.; Chi, J.; Ortmanns, M.
Designing CT ΣΔ Modulators with Shaped Feedback Waveforms using www.sigma-delta.de
23rd IEEE International Conference on Electronics, Circuits and Systems (ICECS), Monaco
December 2016
5.
Wagner, J.; Reich, S.; Ritter, R.; Anders, J.; Ortmanns, M.
Finite GBW in Single OpAmp CT ΣΔ Modulators
23rd IEEE International Conference on Electronics, Circuits and Systems (ICECS), Monaco
December 2016
4.
Chi, J.; Ritter, R.; Wagner, J.; Ortmanns, M.
Phase Noise vs. Jitter Analysis in Continuous-Time LP and BP Sigma Delta Modulators with Interferers
23rd IEEE International Conference on Electronics, Circuits and Systems (ICECS), Monaco
December 2016
3.
Chu, C.; Wagner, J.; Al Marashli, A.; Chi, J.; Ortmanns, M.
A Study on Op-amp Nonlinearity in a Single-bit CT Modulator Employing GBW Compensation
Conference on PhD Research in Microelectronics and Electronics (PRIME 2016), Lisbon, Portugal
June 2016
2.
Wagner, J.; Ritter, R.; Ortmanns, M.
STF Engineering in CT Sigma-Delta Modulators using www.sigma-delta.de
Conference on PhD Research in Microelectronics and Electronics (PRIME 2016), Lisbon, Portugal
June 2016

Gastwissenschaftler

Johannes Wagner