RF Power Amplifier Engineer (m/w/d)

ZeroPhase GmbH; München; On-site; EUR 70,000 - 110,000; Full time

Job summary

ZeroPhase GmbH in Munich seeks an experienced RF Power Amplifier designer to bridge DSP concepts with hardware. You will design high-efficiency PAs tailored for software-defined waveforms and integrate from schematic capture to prototyping in a lab setting.

You will perform non-linear simulations, optimise for PAE and ACLR, and collaborate with DSP engineers on DPD to improve linearity. Expect hands-on testing with VNA and spectrum analyzers in a dynamic RF lab.

Qualifications

• 3+ years of industry experience focused on RF power amplifier design.
• Expertise in non-linear circuit simulation using ADS or AWR.
• Deep understanding of PA architectures for SDR, GaN or LDMOS.
• Experience with wideband matching networks for SDRs.
• Hands-on with VNA, spectrum analysers, and power meters.
• Knowledge of how SDR waveforms affect PA thermal and linearity.
• Bachelor's or Master's degree in electrical engineering, RF/microwaves.

Responsibilities

• PA design & integration: design and develop high-efficiency RF PAs for software-defined architectures (e.g. Doherty, Class E/F, or outphasing).
• Modelling & simulation: perform non-linear circuit simulations (load-pull, harmonic balance) using ADS or AWR to optimise for gain, PAE, and ACLR.
• Linearisation: collaborate with DSP engineers to implement DPD to maximise PA linearity.
• Hardware realisation: drive end-to-end from schematic capture and PCB layout to prototyping.
• Characterisation: perform measurements of modulated signals (EVM, peak-to-average power ratio) across SDR-driven waveforms.
• Automation: write Python scripts to automate PA characterisation across temperature, frequency, and voltage corners.

Skills

RF PA design

Non-linear simulation

GaN / LDMOS

Matching networks

Test equipment (VNA)

PA linearity & SDR

RF/Microwaves degree

Education

Bachelor's/Master's in EE (RF/microwaves)

Tools

ADS

AWR Microwave Office

Job description

You will bridge the gap between digital signal processing and physical transmission, ensuring our software-defined waveforms are amplified with maximum fidelity and optimal power consumption.

What you'll do

• PA design & integration: Design and develop high-efficiency RF power amplifiers (PAs) specifically optimised for software-defined architectures (e.g. Doherty, Class E/F, or outphasing).
• Modelling & simulation: Perform non-linear circuit simulations (load-pull, harmonic balance) using ADS or AWR to optimise for gain, PAE (power added efficiency), and ACLR.
• Linearisation: Collaborate with DSP engineers to implement and validate Digital Pre-Distortion (DPD) algorithms to maximise PA linearity.
• Hardware realisation: Drive the end-to-end process from schematic capture and PCB layout (emphasising thermal management and grounding) to hands-on prototyping.
• Characterisation: Perform complex measurements of modulated signals (EVM, peak-to-average power ratio) across various SDR-driven waveforms.
• Automation: Write Python scripts to automate PA characterisation across temperature, frequency, and voltage corners.

What we're looking for

• 3+ years of industry experience specifically focused on RF power amplifier design.
• Expertise in non-linear circuit simulation using ADS (Advanced Design System) or AWR Microwave Office.
• Deep understanding of PA architectures suited for SDR, including Gallium Nitride (GaN) or LDMOS technologies.
• Experience with matching network design for wideband applications to support frequency‑agile SDRs.
• Hands‑on experience with high‑power test equipment: Vector Network Analysers (VNA), spectrum analysers, and power meters.
• Knowledge of how software‑defined waveforms (QAM, OFDM) affect PA thermal and linearity requirements.
• Bachelor's or Master's degree in electrical engineering, with a focus on RF/microwaves.

Bonus: not required

• Experience with thermal modelling for high‑power RF components.
• Familiarity with envelope tracking (ET) techniques to improve efficiency.
• Proficiency in Altium Designer with a focus on RF layout best practices (impedance control, thermal vias).
• Experience designing in the Ku, Ka, or V‑band frequency ranges.
• Knowledge of DPD (Digital Pre‑Distortion) feedback loops and their impact on hardware design.

How the hiring process works

• Intro call. 30 minutes with our recruiting team. We'll learn about your background, and you’ll learn about the mission.
• Deep dive. A working session with one of our RF/PA engineers on a real amplifier design problem.
• Case study, in Munich. A visit to the lab to work through a PA design scenario with the team, in person if you can make it or over Teams if you can't.
• The offer. By now you've likely already met our CEO. This round is where we make it official: fast, transparent, and built around the mission.