Microwave Circuit Design

The compact form factors, thermal variations, and limited power budgets of VLEO satellites require highly integrated and efficient mmW circuits.
Within SFB 1667 “ATLAS” – Project C03, this thesis focuses on the design of key transceiver components such as mixers, amplifiers, PLLs, and frequency synthesizers. After reviewing existing approaches, selected sub-circuits will be modeled, simulated, and optimized for VLEO operation.
The work combines RF circuit design, simulation, and system-level integration, providing hands-on experience in developing mmW hardware suitable for space applications.

Type of Thesis:

BA ✅ FA ✅ MA ✅ 

Relevant Experience:

• Lecture: Microwave Engineering
• Lecture: Microwave Analog Frontend Design 1/2
• Keysight ADS
• Cadance (optional)
• Matlab 

Contact:

Mark Neff

This research aims to design a wideband low-noise amplifier (LNA) covering the full W-band (75–110 GHz), motivated by its growing use in high-resolution radar and satellite communication. Due to high path loss and atmospheric absorption at these frequencies, maintaining signal-to-noise ratio (SNR) through power efficient front-end amplification is essential. The goal is to realize a schematic and layout (for a Master’s thesis) that achieves a competitive figure-of-merit in terms of noise figure, gain, bandwidth, IIP3, and power consumption. Key tasks include a literature review on advanced LNA topologies, circuit design and verification using ADS and Cadence, and final reporting with state-of-the-art comparison.

Type of Thesis:

BA ❌ FA ✅ MA ✅ 

Relevant Experience:

• Circuit Theory
• Semiconductor technologies
• Microwave – mmWave Circuit Design 
• Layouting / EM Simulations
• Keysight ADS, Cadence 

Contact:

Burak Özat

Linearisation of millimeter-wave power amplifiers plays a decisive role in the energy-efficient and sustainable deployment of 6th generation mobile communication networks (6G) exploiting new frequency spectrum to support the demand in continuous growth of data rates. Due to the multi-GHz instantaneous bandwidths of modern high-capacity millimeter-wave transceivers, the linearisation of power amplifiers through conventional digital pre-distortion (DPD) techniques becomes too power-hungry and inefficient. Analog pre-distortion (APD) based on class-C pre-amplifiers presents an efficient, scalable alternative to DPD at high instantaneous bandwidths. However, its implementation is severly hindered by the absence of simulation models capable of accurately predicting the nonlinear characteristics of the underlying transistor technologies. This work uses state-of-the-art transistor technology and measurement instrumentation to obain compact, equivalent-circuit based models for the reliable design of APD circuits for PA linearisation at millimeter-wave frequencies in WR-10 (70…110 GHz) and WR-6 (110…170 GHz). The work is carried out in collaboration between University of Stuttgart, Germany, and Trinity College Dublin, Ireland. The final work programme is determined in trilateral planification between the tutors and the student and comprises  
Survey of the prevailing state of the art
On-wafer characterisation of high-frequency transistors using linear and non-linear network analysis at millimeter-wave frequencies at ILH 
Model development, implementation in VerilogA and parameter extraction at TCD
Model validation through millimeter-wave power amplifier characterisation at ILH.

Type of Thesis:

BA ✅ FA ✅ MA ✅ 

Relevant Experience:

• Theoretical expertise in microwave engineering and microwave circuit design is recommended.

Contact:

Ingmar Kallfass

Other:

The work is carried out in collaboration and joint tutorship with Trinity College Dublin, Ireland. Parts of the work may be carried out at Trinity College Dublin.

A key component for transmitter design is the power amplifier (PA) as last stage of a Tx frontend. 
This PA is responsible for the power generation for long distance communication or radar applications. For high frequency devices the possible output power is limited by the breakdown behavior of the transistors, which is divined by the band gap of the used semiconductor technology. An interesting material for high frequency power amplifier is GaN, due to it´s large breakdown voltage and high fmax. IMS Chips is able to produce GaN Transistor with adjustable threshold voltage. This allows for different power amplifier topologies. In order to use the GaN technology modeling of the devices is needed, in order to design PA.
This thesis is about the developmant of a transistor model based on measurements.

Type of Thesis:

BA ❌ FA ✅ MA ✅ 

Relevant Experience:

• Experience in semiconductor technology/technics
• Experience in microwave cirucit design and technology
• Experience in CAD programs liek ADS, Empro, CST, …

Contact:

Lukas Gebert