This work aims to build a measurement test bench for wideband mixer EVM characterization at sub-terahertz frequencies. A VNA based setups with two frequency extenders are implemented. While one of the VNA sources can be used as the LO input, the other source will be swept over a frequency grid so that the RF output of the mixer under test will be down converted and read out tone by tone. Then the modulated signals are expected be reconstructed from the frequency domain measurement result, which will be demodulated for EVM characterization. A two-tier calibration method is used to extract the absolute power from the target RF channel. The key performance of the mixer under test, such as conversion loss, image rejection ratio and linearity are measured over an IF bandwidth up to 4GHz. Nevertheless, the major challenge for VNA based EVM measurements are the unhandled phase between the two sources of VNA, preventing the system to reconstruct a stable time domain signal. To solve this problem, an auxiliary phase channel setup is proposed, which can carry the unhandled phase information from one of the VNA source, thus providing a stable phase measurement for EVM measurements. To validate the proposed setups, the adjusted phase is derived from measurement results of the MUT channel and the results from the auxiliary channel. A phase stability of $\pm$5 degrees can be achieved with the proposed setups. Finally, EVM characterization is performed based on the proposed setup. A EVM floor of -30dB is achieved with a 300MHz QPSK signal, the error due to thermal noise is reduced due to the narrow band receiver of the VNA.

Dielectric spectroscopy, a non-contact electromagnetic readout technique, offers significant potential in Organ-on-Chip devices for accelerating drug development by enabling non-invasive, multi-layer sensing of tissue barrier integrity. While open-ended coaxial probes are well-established for dielectric spectroscopy in high-loss biological samples, their inherent lack of biocompatibility and impracticality in conventional setups limits their application. This work investigates novel fabrication approaches using printed circuit boards (PCBs) and glass manufacturing techniques to overcome these challenges. A planarized OECP fabricated on a PCB with via-array shielded coplanar waveguides was developed and evaluated. The PCB-based design demonstrated satisfactory electromagnetic performance, biocompatibility potential, and cost-effectiveness, making it a promising candidate for integration into well-plate formats. Additionally, laser-induced deep etching (LIDE) was explored for creating high-precision glass substrates with metalized vias, presenting an alternative route for scalable sensor fabrication. Together, these advancements lay the foundation for adaptable and scalable dielectric spectroscopy platforms suitable for Organ-on-Chip applications, merging performance with practicality in biological settings.

S-parameter measurements are advancing on many fronts, ranging from operational frequencies to supported interfaces to extreme loading conditions. The operational frequencies for VNA-based systems continuously extend in frequency range and at present support measurement capability beyond 1.1 THz. The development of RF devices and systems is progressing across many domains that require the support of many interfaces, ranging from the conventional connectorized coaxial and waveguide lines to the on-wafer planar domain. At the same time, RF devices are becoming smaller and using novel materials that impose challenging measurement loading conditions, such as extreme impedances. These challenges imposed on many fronts for S-parameter measurement have an increased need for sensitivity and accuracy, forming the basis of the work outlined in this book.
The first three chapters ddress measurement challenges in coaxial VNA test benches and describe advanced accuracy improvement techniques. Starting with chapter 1, a detailed overview is provided for the S-parameter measurement challenges addressed in this thesis. From here, chapter 2 extends with an introduction to uncertainty sources in connectorized Vector Network Analyzer (VNA) test benches, measurement models, and uncertainty propagation techniques. This forms the basis for chapter 3, which presents advanced methods and strategies for the evaluation of the uncertainty contributions corresponding to the VNA, test-port cables, and coaxial connectors. Moving forward from coaxial VNA measurement systems, the emphasis subsequently is on the primary realization of S-parameter traceability. Chapter 4 describes a method employing a coaxial air-dielectric transmission line for uncertainty evaluation purposes. Here, an improved ripple method is proposed for evaluating uncertainties of a calibrated VNA using a transmission line standard in combination with the Time Domain Signal Extraction (TDSE) algorithm [1]. Chapter 5 describes an advanced model for calibrating transmission line standards using mechanical and material parameters and forms the basis of primary TRL calibration of coaxial VNA systems. The accuracy improvement techniques for coaxial VNA systems are finally extended
to extreme impedance devices. Chapter 6 focuses on measurement of such extreme impedances and introduces the novel interferometer design for ultra-low-noise and broadband measurements, including a novel calibration method for interferometer-based broadband VNAs. With accuracy methods for both matched and high-mismatched environments established, the final part of this thesis aims to expand accurate measurements to the on-wafer domain. Chapter 7 describes our advancements in on-wafer measurements, focusing on RF probing to develop a fully autonomous on-wafer measurement capability. Chapter 8 concludes this thesis with a summary of its main findings and recommendations for future work.@en

Front-end Monolithic Microwave Integrated Circuits (MMICs) have recently become commercially available for frequencies above 100 GHz. However, achieving low-loss and broadband interconnections between the antenna and MMICs is challenging for integrated front ends at these frequencies. This thesis presents the characterization of a flip-chip interconnection used for an integrated front end at 150 GHz (G-band) with an on-package leaky-wave dual lens antenna. Two paths for the front-end integration have been proposed. The first path adopts CPW transmission lines on 500 μm-thick fused silica and provides easy assembly and seamless flip-chip capabilities. The second uses microstrip transmission lines on 50 μm-thick fused silica and provides lower transmission line loss but a challenging assembly and flip-chip interconnection. In this thesis, a path toward microstrip and CPW flip-chip interconnections has been outlined at the high millimeter-wave frequencies. Two-port test structures using CPW transmission lines were developed, adopting a double Thru-Reflect-Line calibration and allowing for accurate extracting of the interconnection response. The final interconnection to the MMICs has been realized using a via-less CPW to microstrip transition with high impedance transmission line S11 matching compensation. The simulated S11 and S22 are below -12 dB, Ohmic loss below 0.6 dB, radiation loss below 0.4 dB, and transmission line losses around 0.15 dB/mm.

A new antenna measurement setup, the Antenna Dome, is being developed, which can provide real time antenna and beamformer measurements. In order to be able to validate this setup, an existing beamforming system will be will be extensively studied and characterized. Multiple measurement setups will be used, providing multiple measured characteristics. The result is an accurate statistical model for the steering system, and a comprehensive error model for the complete beamforming system, including the provided antenna array. This model will help in validating the functionality of the Antenna Dome, and ultimately will help in its further development.

In this thesis, the realization and qualification of an anechoic dome chamber for 5G antenna’s is discussed. As with audio, where no echoes or noise from outside is wanted when listening to music, when characterizing an antenna it must be prevented to get internal reflections or electromagnetic (EM) radiation from outside. For this reason, a measurement setup was simulated, using that setup, different absorbers were tested and characterized. And a Faraday cage shielding is designed and evaluated, to remove EM interference. To make the anechoic chamber physically possible, rebuilding the minidome was also required, so that the absorber and Faraday cage could be mounted on the inner wand of the dome. Eventually, a suitable test environment for 5G antenna’s is build. In the end, the assessment of the absorbing materials was completed, and the chamber achieved all requirements. Despite the space of improvement, the idea of building an anechoic chamber is successfully verified.

Nowadays, recent Integrated Circuit Technology demands a minimum metal fill inclusion across the entire die of each functional layer to have uniform planarity. It is challenging to numerically simulate the real structure using Electromagnetic (EM) solvers because the mesh size of an EM solver is inversely proportional to the number of vertices in the layout and the inclusion of these metal fills has a significant impact on these vertices and increases mesh size. It is important to understand the metal fills do have an impact on the RF performance of the component and the impact becomes stronger as the frequency increases due to the parasitics and hence we cannot neglect it. Therefore, a Design Flow Methodology is studied and analyzed to take into account the effect of metal fills without penalty in accuracy and simulation time.

The second part of the thesis focuses on two different approaches that can be used to extract the complex parameters providing the electromagnetic response of the layers, i.e. electrical permittivity and magnetic permeability. First, we describe the Quasistatic approach to extract the epsilon parameters from the capacitance and inductance. After, describing some of the limitations of this approach we focus on the Oblique Incidence Method as reported in the literature to extract the complex epsilon tensor parameters.

The third part of the thesis looks into the Design Flow Methodology that embeds the Oblique Incidence Method into the design flow for 3D EM solvers to take into account the effect of metal fills. The 2.5D EM solver takes into account a scalar number which is less accurate and hence an insight of how the solution from the Oblique Incidence Method can used to extract a scalar number for the effective parameters and therefore be implemented in 2.5D EM tools is discussed.

The fourth part of the thesis shows the validation of the Oblique Incidence Method for the 3D EM tool for two test cases which are wave propagating structure and lumped structure namely Grounded Coplanar Waveguide (CPWG) and Stacked Transformer. Validation of the Scalar Number Approaches for the 2.5D EM Tool was done for the CPWG structure.

Finally, a brief study on the Design Based Approach is conducted with different metal fill shapes and alignment by using the Oblique Incidence Method by making use of 3D EM tool. This approach provides a better understanding of the epsilon variations for different metal fill shapes and that for less epsilon variations, an accurate scalar number value can be extracted to enable 2.5D EM simulations with improved accuracy.

In the ADome project, a truncated icosahedron is used as a frame for multiple antenna nodes. These nodes are used to measure the radiation pattern of an antenna-under-test located in the center of this dome. Since these antennas can be placed anywhere in the ADome by the user, a calibration system is necessary to find the spherical coordinates of each of these antennas.

In this thesis, a method is proposed that uses computer vision algorithms, written using the OpenCV library in C++, to locate each of these antennas by detecting controllable LEDs attached to the PCBs of the antenna nodes. The found pixel locations will then be used to get the spherical coordinates of the antennas with respect to the camera. Finally these spherical coordinates will be transformed to fit to the coordinate system of the ADome itself, by detecting landmarks in the form of fiducial markers which are located at predetermined locations.

The methods of recognition of the antennas within using computer vision are discussed, implemented and tested on real and simulated data. The accuracy of finding the antennas on the real data was within 2 pixels from the true location.

The methods regarding estimating the location of the antenna with respect to the camera are discussed next. These methods include a distortion estimation and correction, after which each pixel will get there corresponding spherical angles θ and φ. These methods are also tested on simulated and real data, where the accuracy on the real data falls within 0.5 degrees in comparison to the true data.

Finally the methods of transforming the spherical angle θ and φ of the antenna with respect to the camera, to the coordinate system of the ADome are discussed. This starts with a method of recognizing fiducial landmarks (landmarks are accurately known reference points), where in this research there is chosen for ArUco fiducials. After this, the location of these landmarks can be used to determine the location and orientation of the camera within the ADome. The method of finding the distances between each of the landmarks and the camera, is discussed and tested and has an accuracy of 2 cm. The method of finding the location of the camera, and the method of finding the orientation of the camera are discussed, however this has not been tested and fully implemented yet. With this location and orientation the location of an antenna can be easily determined.

In conclusion, this thesis is a good starting point for designing an Optical Calibration System, which could make determining the location of each of the antennas faster, and more accurate.

This thesis focuses on improving the readout of the ADome by implementing MCUs at each antenna probe, enabling local sampling and memory storage. The serial communication protocols CAN, SPI and I2C are considered and compared with one another. Ultimately, CAN is decided due to its robustness and simplicity which make the system cheap and ensures that the measurement will not get corrupted during transmission. Moreover, implementations of the new readout protocol are able to obtain measurement data store information at the local MCU. Test setups verification showed that antenna location can be stored and retrieved. Furthermore, the readout protocol is able to acquire multiple samples from the ADC locally.

The accuracy of a true-RMS detector board based on the Analog Devices LTC5596 is determined by measuring the input power and the output voltage. A number of samples of the output voltage is taken and the mean and standard deviation is shown. These measurements are done for single-tone excitation with a direct connection and over-the-air setup, and for multi-tone excitation with a direct connection.

It has been demonstrated that the detector response worsens with over-the-air excitation, resulting in a doubling of the standard deviation in the output voltage compared to a direct connection. With multi-tone excitation, the standard deviation is fifteen times higher than with a direct connection. Additionally, with multi-tone excitation the mean output voltage is lower than with the same input power as single-tone. This discrepancy increases with the amount of tones.

A Keysight Advanced Design System simulation is also presented for the three different measurement setups. With the use of a Monte Carlo simulation uncertainty bounds between the function generator and the power detector are made. Furthermore the noise of the power detector is simulated and sources of noise analyzed.

The commercialization of millimeter wave frequencies for the 5G New Radio standard requires time and cost -effective testing equipment. The over-the-air measurement setup developed at the TU Delft (ADome) is able to reduce measurement time, by positioning multiple fixed sensing nodes around the antenna-under-test. To expand the system capabilities of the ADome, this work researches the possibilities of measuring signal quality by down-converting the high-frequency modulated signal to an intermediate frequency. This includes analysis on distributing the local oscillator to the sensing nodes, a proposed design and simulation of a passive single-balanced diode mixer circuit and simulated system EVM performance.

Commercial interest for millimeter-wave wireless communication has increased significantly over the past years due to the appearance of large volume applications such as automotive radar and telecom applications, i.e. as 5G systems operating in the FR2 band, ISM applications in the 60 GHz E-band, and beyond 100 GHz in the W-band and D-band. Developments in this frequency range are enabled by the continuous improvements in silicon-based technologies over the past decades and are driven by frequency congestion in low-GHz bands. To support development for these applications there is a demand for new millimeter-wave test equipment, de-embedding/calibration methods and device characterization approaches. Three topics related to challenges in millimeter-wave on-wafer characterization are addressed in this work.

A novel characterization method is developed for in-band linearity estimation that overcomes the limitation of harmonically generated spectral content by the frequency extension modules in the millimeter-wave active load-pull setups. The method is able to estimate trends in the EVM across input drive level, frequency and loading condition from vector gain measurements of the active device. On-wafer measurements were performed to benchmark the method against true EVM measurements in two sub-30 GHz bands. A proof of concept demonstration at 165 GHz showed the ability of the method to estimate trends for in-band linearity across drive level and loading condition at millimeter-wave.

A new parametrized 16-term error model and calibration algorithm was developed to overcome probe-to-probe cross-coupling effects during millimeter-wave on-wafer characterizations. Conventional 16-term calibrations are not practical as these are only effective if the probe-to-probe spacing is not changed after calibration. This new approach allows for interpolation of the error terms for devices under test that have a pad spacing not included in the set of calibration standards. This makes the method powerful and practical as it would only require one set of calibration structures for large-scale on-wafer measurements of devices with a different pad spacing.

Finally, a preliminary investigation was performed into active device behaviour when operating close to the maximum oscillation frequency of the technology. This investigation is conducted using on-wafer millimeter-wave large signal measurements on a 22-nm CMOS FD-SOI technology. A new experimental method is proposed that could show different operating behaviours when moving towards the maximum oscillation frequency. This approach uses large-signal (load-pull) measurements of the device across power and supply voltage. Under the hypothesis that a slew rate like operation is obtained when the maximum oscillation frequency is approached, this characterization may show the transition point in frequency for the onset of such device limiting behaviour.

Due to the earth’s population growth and the increased living age of a person, more and more people could deal with medical problems. Early detection of health related problems in both healthy and people with medical problems, will catch problems early and prevent the need for more costly procedures. One of these medical problems is concerning the hydration level. Dehydration most often occurs for elderly people. To prevent sickness and even death, monitoring of the hydration can play a key factor in prevention. Hydration monitoring can be established by using a designed CMOS permittivity sensor. However, to design a commonly used hydration monitoring device, this CMOS permittivity sensor needs to be designed in such a way that portable sensing could be enabled. To design such a portable hydration sensor from an application sensor, different steps are required. To bring previously developed sensor to enable hydration monitoring, it need to be packaged in such a way that it can sense the medium of interest and be connected to the outside world while sufficiently protected, so that it will not damage during use. Different packaging procedures could be distinguished to accomplish this. The first packaging procedure is regarding the creation of SU8 metallized pillars. The second packaging procedure is for creation of cavities in SU8 and fill these cavities with aluminium particles. Besides the packaging of the sensor chip, validation measurements are required to ensure that a relationship could be detected with the permittivity sensor between the hydration level of the human skin. To enable measurements of the skin permittivity without bulky systems, a PCB layout should be designed.

Until now parameter analysers for Organ-on-Chips (OoCs) have needed bulky multi-probe setups that do not fit in biological research labs. For this reason a bachelor graduation project was proposed to get one of the sensors designed by the Electronic Components, Technology and Materials group (ECTM) out of the lab and into the hands of potential end users. This thesis is one of three from that project, and describes the calibration and user interface components of the portable parameter analyzer that is developed for the OoC sensor.

First, an analysis is performed on the amplifier design that was given with the sensor. The analysis showed that the biggest sources of error in the overall gain are the offset and gain error, while non-linearity was not significant. Therefore, a two-point calibration method was deemed sufficient for the amplifier calibration. It is performed by taking two reference voltages as input of the amplifier, and measuring the corresponding output. With those points the actual gain and offset voltage can be calculated and corrected in measurements.

Because of circumstances it was not possible to test in a lab environment whether the amplifier and the two-point method would meet the requirements. Therefore a second calibration method is proposed, the `sweep' method. For each input voltage step the corresponding output voltage is measured. This mapping can be stored in memory, and any future measurement can be looked up to find the correct voltage. The sweep method can also be used with a slight modification of the current hardware in order to simply plot the gain of the amplifier, to verify that it is linear as intended.

Because the portable parameter analyzer is operated remotely, there was a need to develop a communication protocol on top of the Bluetooth link, in order to allow for parallel development of the GUI and embedded software on the analyzer. Once the communication between GUI and analyzer was defined, it was also possible for the other group to calculate the power consumption of the communication module.

Finally, a Graphical User Interface (GUI) needs to be developed that can interact with the analyzer (connect, change settings, retrieve data, etc.) and it should display and store the measured data. A framework called Qt is chosen for developing the GUI, and a graphical design was made. Two modules are implemented in the GUI: A Bluetooth scanner to connect to the analyzer, and a way to plot data from the analyzer.

Problems in drug development and personalised disease treatments are the main impulse for the development of OoCs. At the Electronic Components, Technology and Materials (ECTM) group at TU Delft an OoC sensor has been developed and the design is now at a stage where a system can be developed to take the sensor out of the initial research environment, into a complete product that incorporates the sensor. In this thesis a design is proposed for a portable parameter analyser based around the STM32L4 microcontroller platform. It contains an instrumentation amplifier and a communication module to connect to an external device. A power consumption estimation is made for individual system components as well as for the system as a whole. From this it is concluded which components contribute the most to the power consumption and recommendations are made on how to decrease this power consumption.

Real-time cell culture media monitoring can be conducted by Organ-on-Chip (OoC) ion-sensitive floating-gate field-effect transistor based sensors (ISFGFET). A method of modelling the sensor is described and implemented in the Advanced Design System (ADS) design and simulation software. The model is validated using measurement data of the sensor when exposed to an aqueous solution and in a 'dry' scenario. The model is utilized for an overall sensitivity analysis and the effect of the sensor dimensions on the sensitivity to charge variation that are immobilized on the sensing area surface. In addition to a SPICE compatible floating gate, level 3 MOSFET parameters are extracted, along with a sensing area model that links changes in the floating gate voltage to changes in the pH of the solution. Subsequently, a bias point is determined based on measurement data and limiting factors. Finally, the sensitivity of the ISFGFET is analysed. Our results characterize the effect that the sensing area dimensions, control gate capacitance and bias point have on the sensitivity.

In recent years, the demand for the wireless connectivity is increasing and leads to the research into the above 100GHz design. Developments have been made with the circuit and technologies to make the circuit operate at 100GHz. The current availability of silicon-based technologies providing devices with ft/fmax frequencies exceeding 300-GHz allows targeting above 100GHz for commercial telecom links.
The project presents an automated design approach that utilizes “Ocean” and “Skill” code to automate parts of the design flow of the mm-wave power amplifier. The Ocean script, the scripting language used by the cadence environment to control the simulations, together with Matlab is applied for data handling and to automate lots of the recurring simulations. The Skill-code, which under the cadence’s environment is applied to automatically generate the tunable layouts to realize a DRC conform circuit design.
The design of a 170-GHz Power Amplifier in 0.13-μm SiGe BiCMOS applied the automation design flow is presented in this thesis. The gain-stage characteristics such as gain, stability, power-added-efficiency, saturated output power or 1dB-Compression are automatically generated and plotted. Specifically, this 170-GHz PA achieves a 15dB power gain and 11.7dBm output 1dB compression point.

To solve extant complications with standard wafer-probing techniques, such as probe-to-probe coupling and probe-tip deterioration, a novel probe tip device has been designed and verified by means of 3D EM-simulation for the 220-325 GHz frequency band. The new probing technique uses an on-wafer cavity-backed slot to couple the signal to a tapered structure in an open-ended waveguide which is held above the cavity, and acts as a fully shielded transition from the transverse electromagnetic mode of the planar stripline to the fundamental transverse electric mode of the waveguide. The on-wafer structure used for the transition is limited to the back-end-of-line of the process, and is shielded from the ill-characterised substrate. The transition achieves an insertion loss of <1.8 dB across the entire 220-325 GHz band and does not require galvanic contact with the die. The layout for the on-wafer structure has been designed for a 0.25 µm SiGe process and a simplified version has been used for a simulated sample measurement using the thru-reflect-line calibration algorithm. Due to coupling to nearby structures, the novel probing technique show significant improvement over the standard coplanar probes only when a chip area greater than the cross-section of the open-ended waveguide is reserved. Simulated measurement of an independent passive structure show a reduction of the average worst case bound from 0.041 to 0.017 in the 220-325 GHz band.

The recent development of commercial phased array antennas for 5G at mm-wave frequencies (20 GHz to 60 GHz) introduces new challenges for radiation pattern characterization. Since these systems aim to employ active beamforming to steer the datastream to specific users, a single base station should be capable of deploying multiple beams simultaneously and electronically steer them to track the user. This introduces the need to characterize a large set of parameters and configurations.
As these modules become more cointegrated with the underlying transceiver chain, its internal modules are becoming less accessible and the device should be considered a unique black box for characterization purposes. Since the difficulty of sub-component testing increases, verifying antenna systems must be performed in an over-the-air (OTA) setup for the entire module.
Current antenna characterization utilizes a single probe, which relies on mechanical rotation to move the sensor around the antenna under test (AUT). This is a proven method, but typically takes several hours, depending on the required resolution. This becomes tedious and commercially unaffordable when multiple measurements are required. Furthermore, these systems require additional instruments, e.g. a vector network analyzer (VNA), which significantly increases the cost of the setups.
The concept proposed in this work avoids these drawbacks. It employs a large number of fixed sensing elements, enabling real-time radiation pattern acquisition. This has the potential to significantly reduce measurement time of 5G antenna systems. A key factor is the sampling of the signal right at the antenna probe, in contrast to the expensive VNA commonly used. This results in a lower complexity and cost, since there are significantly less high frequency components compared to other setups.
A prototype of this concept has been developed for two cross-sections of a dome, which provides real-time antenna pattern tracking capabilities. The high level of flexibility allows easy adaptation to different antenna systems. The sensing probes provide direct downconversion at the antenna, eliminating the need for a VNA. Furthermore, an algorithm is made that calculates the required number of sensor nodes depending on the antenna system under test. The high speed, modularity and low cost allow this setup to be an effective option for instantaneous verification of beam-steer capable antenna systems in the development and fabrication. This can ease the predicted antenna measurement bottleneck expected for the broad employment of small-cell 5G networks. The concept can be expanded to include features such as jammer injection and instantaneous error vector magnitude (EVM) measurement.

This work focuses on the improvement of a capacitance-to-digital converter (CDC) based on iterative discharging. Time-domain interpolation is applied on the CDC. With such technology, a high-resolution CDC can be achieved while its fully digital feature can be kept. The proposed CDC achieves a resolution of 2.8fF and a FoM of 1.32pJ/step at 5.5pF capacitance. A MEMS capacitive pressure sensor has been bonded to the chip and the output with varying capacitance has been checked.