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.

Quantum sensing technology has emerged as a promising field with superior sensitivity and accuracy in magnetic field sensing compared to conventional technologies. This breakthrough offers significant prospects in the biomedical sector, particularly in the realm of medical imaging. This project focuses on the implementation of quantum sensing using an array of single Nitrogen Vacancy (NV) centers combined with an array of Single Photon Avalanche Diodes (SPADs). SPADs are available in various technologies and forms. To identify the optimal SPAD for this specific application, different SPADs with diverse parameters are designed on a chip using standard 40 nm TSMC process. These parameters include active area, active area shape and metal shielding. The research aims to validate and characterize the performance of these distinct SPADs. However, during the validation tests, it was observed that the SPADs did not meet the criteria. The presence of ESD diodes on the chip introduced a low resistance current path, thereby hindering the characterisation process of the SPADs. Solutions to fix this problem and improve the system are provided. The documented validation methods include general chip testing, establishing the I-V curves of the SPADs and avalanche and quenching testing. In addition, the characterisation methods for junction capacitance, dark count rate (DCR), photon detection probability (PDP) and time jitter are given. For characterizing DCR and PDP a readout system is designed. It consists of an analog-to-digital converter (ADC), FPGA and Arduino. The data is communicated continuously to a PC. The ADC is not fully tested. On the other hand, the FPGA and Arduino are tested and verified to be sufficient for the DCR measurements. The readout system is too inaccurate for PDP measurements. A recommendation on how to make the readout system sufficient for PDP is given.

Millimeter- and submillimeter wave applications, such as point-to-point wireless communications in beyond-5G scenarios, long-range automotive radars and astronomy and astrophysics science cases from space require antennas with high-gain beams that are steerable. At lower (microwave) frequencies, fully sampled phased arrays with thousands of elements have been demonstrated for this purpose. However, above roughly 100 GHz, integrated-circuit technology faces major bottlenecks in terms of size, power efficiency, thermal management and technological immaturity. Consequently, only integrated phased arrays with very few elements have been reported in the literature above 100 GHz. To still achieve the gain and enable beam scanning, mechanically actuated reflectors are now typically employed. However, such solutions are bulky, power-hungry and do not allow rapid beam steering. To overcome these limitations, we propose, analyze, design, fabricate and demonstrate a new antenna architecture in this thesis: the scanning lens phased array. The scanning lens phased array is a compact, low-power and very sparse array of integrated lens antennas that we demonstrate with scanning capabilities up to 25 degrees around broadside. A hybrid electro-mechanical approach to beam steering is employed: the array factor is scanned electronically and the element patterns are steered mechanically. The grating lobes that arise in the array factor due to the array’s sparsity are suppressed by the high directivity of the lens elements. This results in a clean, highgain beam towards the desired scan angle...@en

Neonates are among the most fragile in the human population. Even more so when born prematurely. Their loss of development time in the womb disrupts their growth, and the neonatal intensive care unit environment can add multiple stresses that hinder their development. This can partly be attributed to the intrusive environment of a neonatal intensive care unit incubator. Neonatal development cannot be monitored without multiple wires and sensors, such as pulse oximetry and electrocardiogram (ECG). The strong adhesives of these sensors can hurt the delicate skin of the neonates and the sensors make bonding with parents difficult. The issue of the intrusive nature of current neonatal healthcare has led this thesis towards something not normally associated with healthcare: radar. Millimeter wave radar with frequency modulation of the continuous wave transmission has been shown to measure adult’s heart and respiration rate without contact with the patient. Using the small wavelength and high configurability of frequency modulated millimeter wave radar, the goal will be to scale down this technology from adults to neonates that can be as small as 500 grams. This thesis provides a look into the application investigation of frequency modulated millimeter wave radar in monitoring neonates. It dives into the environment of the neonatal intensive care unit incubator and the radar monitoring system operation. The environment is modelled with a thermal focus to avoid high temperature increases caused by the radar module. The system operation is described and the most influential component simulated and characterized. Lastly, the thermal model of the neonatal intensive care unit incubator is validated to understand how the system operation influences the environment. And the radar system operation will be characterized for measuring the smallest amplitude changes of a chest to understand how the environment influences the system performance. The conclusion of this thesis will provide reasoning for why or why not the application of frequency modulated millimeter wave radar has the capability to be safely implemented in the neonatal intensive care unit.

This work demonstrates the imaging of (near) diffraction-limited images in the THz domain using a CMOS integrated camera. A Quasi Optical Setup is fabricated, aligned the radiation patterns and losses are characterized.

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.

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.

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.

This thesis is concerned with a first time demonstration of a high frequency scanning lens phased­-array with dynamic steering. Such phased­-array could provide the high gain, wide bandwidth, and steering capability that the next generation of wireless ap­plications requires. The phased-­array development was divided into three distinct parts. First, the electronic phase steering system was discussed and developed, and its stability was characterized over time. Results obtained over 24 hours indicated that the system would be stable to within 6° of high frequency output phase. The drifts in output amplitude remained to within 0.3dB. Next, the lens antenna elements were developed with a novel corrugated leaky ­wave feed that provides very high and broadband aperture efficiency. Antenna measurements have validated its ability to be a very aperture efficient radiator (>80%) with wide bandwidth (1:2). Scanning measurements have shown a 3dB scan loss at around 15°. Finally, the phase steer­ing and antenna elements were combined into a 4×1 array concept. Its behaviour was simulated and indicated again good performance with wide bandwidth (1:2) and high directivity (31.5dBi). Simulated scan loss was approximately 3dB at 20°. The amplitude and phase errors resulted in a SLL standard deviation of 0.63dB. The array prototype is currently awaiting completion of fabrication by DEMO at the TU Delft.