A journal of circuits, signals and code.
Blog
OpenRoomCal: A simple speaker calibaration app
Writing in progress. This article is currently in development.
Coffee Tracker: A shared coffee accounting system for small teams
Writing in progress. This article is currently in development.
Extending the Bandwidth of Piezoelectric Transducers with Passive Compensation
A practical study on extending the bandwidth of a piezoelectric transducer using passive R-L compensation and circuit optimization
03/12/2024
Spark Gap Discharge as Ultrasonic Sound Source
An experimental impulsive broadband ultrasonic emitter using spark discharge and acoustic horn filtering
03/12/2024
uDSP-Card: XCORE.AI Development Board for Portable Applications
A compact DSP development board for real-time embedded audio and sensing
03/12/2024
A Note on Room Impulse Response (RIR) measurement quality metrics
Writing in progress. This article is currently in development.
Harmonic Fusion: A Electro-Smith DAISY based Eurorack Module
Writing in progress. This article is currently in development.
A Note on Spatial Distribution of the Diffuse Energy in Reverb
How surface absorption coefficients influence the spatial distribution of diffuse sound energy in room reverberation
14/09/2021
Multithreaded Operating Point Simulation with ngSpice and KiCad
Writing in progress. This article is currently in development.
Work Experience
Hardware Design Engineer
Linque GmbH09/2025 - present
Running the electronics development workflow for a PIC-based optical circuit switch (OCS): requirements → proposal → specification → design → manufacturing → validation
- Deriving engineering requirements from PIC specifications and product requirements
- Architecting a scalable, cost-effective, low-power mixed-signal sensing and control platform for the PIC
- Simulating and validating mixed-signal signal chains with Python/SPICE co-simulation and Verilog testbenches
- Designing schematics and multilayer PCB layout (SI/PI, EMC/EMI, DFM/DFT)
- Bringing up and debugging new boards on the bench
- Driving NPI and manufacturing readiness with external EMS partners
Research Intern
Georg Neumann GmbH01/2024 - 03/2024
Developed a background-noise-adaptive room impulse response measurement algorithm using Python
Teaching Assistant
Professorship AIP, Technical University of Munich04/2023 - 07/2023
Supervised coding classes (~10 participants) on signal processing for audio effects using MATLAB
Working Student, Audio Engineering
Harman GmbH03/2022 - 10/2022
Developed and validated algorithms for loudspeaker equalization in car audio systems using MATLAB
Working Student, Circuit Design
Silver Atena GmbH09/2021 - 02/2022
Designed and simulated a high-power CLLC resonant converter using ngSpice and Python
Education
M.Sc. Electrical Engineering and Information Technology
Technical University of Munich04/2022 - 03/2025
- Relevant coursework: ASIP Design Hackathon, Deep Learning and Inverse Problems, DSP for Audio Technologies, Embedded System Design for Machine Learning, Embedded Systems and Security, Machine Learning and Optimization, Multirate Signal Processing, Musical Acoustics, Seminar on Audio Research, Technical Acoustics, The Auditory System
- Master’s thesis on “Ultrasonic Hearing for Human Echolocation”
Master’s Thesis
Acoustics Lab, Aalto University06/2024 - 11/2024
- Designed hardware and DSP of a wearable PoC device for ultrasonic-based spatial echolocation
- Included a multiboard design with an XMOS MCU, broadband impedance-compensated piezo transducers, ultrasonic arc unit, MEMS microphone array, wireless capability, and BMS
- Supported by the EIKON e.V. scholarship (TUM)
B.Sc. Electrical Engineering and Information Technology
Technical University of Munich10/2018 - 03/2022
- Relevant coursework: Amplifier Circuits, Communication Acoustics, Real-Time Systems, Real-Time Programming Lab, Signal Processing
- Bachelor’s thesis on “Simulation of diffuse reverb with scattering coefficients”
Tools & Technologies I Use
Languages & Libraries
C, C++, JUCE, MATLAB, Python, Qt, VCV Rack
Embedded Platforms & RTOS
ESP32, Embedded Linux, FreeRTOS, Rockchip, STM32, XMOS
FPGA & RTL
Certus-NX, MachXO, Radiant, SymbiYosys, VHDL, Verilator, Verilog, Vivado, Zynq UltraScale+ MPSoC
Circuit Design & Simulation
Altium, DFM/DFT, EMI/EMC, KiCad, LTspice, SI/PI, ngSpice
Design & Prototyping
FreeCAD, OpenSCAD, Penpot, Vectary, draw.io
Productivity & Documentation
Git, Obsidian, ResearchRabbit, Texifier, Zotero
Connect
Feel free to contact me at christoph.kiener@outlook.com