Dr. Adrian Keller

Experienced RF and Antenna Engineer with over 10 years of expertise in the design, simulation, and optimization of high-performance antenna systems, microwave circuits, and embedded wireless modules. Specialized in compact antennas for IoT, GNSS, radar, and 5G applications. Adept in full-wave simulation using CST, HFSS, and FEKO, as well as PCB design, impedance matching, and EMI/EMC mitigation. Comfortable working in multidisciplinary teams or as an independent consultant.

Features

• Embedded and PCB-integrated antenna design (chip, FPC, patch, inverted-F, fractal)
• Full-wave electromagnetic simulation (CST Microwave Studio, HFSS, FEKO)
• S-parameters and network analysis (S11, S21, isolation, coupling)
• Microwave component design (filters, couplers, power dividers)
• GNSS, LTE, Wi-Fi, BLE and UWB antenna tuning
• Impedance matching, baluns, and matching networks
• Enclosure integration and material effects (plastic, metal, absorber)
• Radar and phased array systems (L-band to Ka-band)
• EMI/EMC shielding analysis and mitigation
• Prototyping, measurement, and test using VNA and anechoic chambers
• Firmware integration (STM32, ESP32, Nordic nRF)

Professional Experience

Freelance RF & Antenna Design Consultant
Remote (Global clients) • Jan 2019 – Present

• Designed and simulated over 60 custom antennas for BLE, Wi-Fi, NB-IoT, GNSS, and radar modules
• Provided remote EMI/coexistence analysis for complex multi-antenna PCBs used in tracking and automation systems
• Delivered full HFSS/CST simulation projects with detailed documentation and tuning guides
• Developed a Python-based toolkit for 2D/3D radiation pattern post-processing from .s1p and .csv exports
• Advised a US-based startup on antenna layout and matching strategies, reducing return rate by 32% after redesign

RF Systems Engineer – Navtech Aerospace GmbH
Munich, Germany • Sept 2014 – Dec 2018

• Led antenna design for aeronautical GNSS and L-band communication systems
• Designed miniaturized dual-band patch antennas embedded in composite fuselage materials
• Performed system-level simulation of phased arrays for air-to-ground radar
• Created HFSS macro scripts for parametric sweeps and automated mesh tuning
• Coordinated measurement campaigns in anechoic chambers and field-testing facilities

Education

Ph.D. in Electrical Engineering (Microwave Systems)
Technical University of Munich (TUM) • 2014
Dissertation: “Low-Profile Antennas for Compact GNSS Receivers under Harsh Environmental Conditions”

B.Sc. & M.Sc. in Electrical Engineering
RWTH Aachen University • 2008 – 2012
Focus: Electromagnetics, High-Frequency Circuit Design, Embedded Systems

Certifications

Certified RF Design Specialist – IEEE Microwave Society
CST Advanced Modeling & Optimization Certificate
ADS (Advanced Design System) Training – Keysight Technologies