Millimetre Wave Power Measurement

There is currently no traceable power sensor for millimetre wave frequencies above 110 GHz. This thesis investigates a novel approach to remove this limitation by combining the placement of a uniquely designed microchip directly in waveguide. The design of the chip is novel in that it does not rely on a supporting structure or an external antenna when placed in the waveguide. The performance of the design was primarily analysed by computer simulation and verified with the measurement of a scale model. The results show that it is feasible to measure high frequency power by placing a chip directly in waveguide. It is predicted that the chip is able to absorb approximately 60% of incident power. Any further efficiency would require modification of the chip substrate. However, this proposed design should allow the standards institutes a reference that will enable the calibration of equipment to beyond 110 GHz

A Wideband 77-GHz, 17.5-dBm Fully Integrated Power Amplifier in Silicon

A 77-GHz, +17.5 dBm power amplifier (PA) with fully integrated 50-Ω input and output matching and fabricated in a 0.12-µm SiGe BiCMOS process is presented. The PA achieves a peak power gain of 17 dB and a maximum single-ended output power of 17.5 dBm with 12.8% of power-added efficiency (PAE). It has a 3-dB bandwidth of 15 GHz and draws 165 mA from a 1.8-V supply. Conductor-backed coplanar waveguide (CBCPW) is used as the transmission line structure resulting in large isolation between adjacent lines, enabling integration of the PA in an area of 0.6 mm^2. By using a separate image-rejection filter incorporated before the PA, the rejection at IF frequency of 25 GHz is improved by 35 dB, helping to keep the PA design wideband

MMIC devices for active phased array antennas

The use of finlines for microwave monolithic integrated circuit application in the 20 to 40 GHz frequency range. Other wave guiding structures, are also examined from a comparative point of view and some sonclusions are drawn on the basis of the results

Wideband and UWB antennas for wireless applications. A comprehensive review

A comprehensive review concerning the geometry, the manufacturing technologies, the materials, and the numerical techniques, adopted for the analysis and design of wideband and ultrawideband (UWB) antennas for wireless applications, is presented. Planar, printed, dielectric, and wearable antennas, achievable on laminate (rigid and flexible), and textile dielectric substrates are taken into account. The performances of small, low-profile, and dielectric resonator antennas are illustrated paying particular attention to the application areas concerning portable devices (mobile phones, tablets, glasses, laptops, wearable computers, etc.) and radio base stations. This information provides a guidance to the selection of the different antenna geometries in terms of bandwidth, gain, field polarization, time-domain response, dimensions, and materials useful for their realization and integration in modern communication systems

E-plane parallel coupled resonators for waveguide bandpass filter applications

High skirt selectivity and extended out-of-band rejection is a major challenge for the successful progress of in-line microwave filters. This thesis presents novel filter realizations with improved performance, compatible with the standard single thin all-metal insert in a split-block housing and therefore maintaining the low-cost fabrication characteristics. In addition, significant filter performance improvement is achieved. The synthesis procedure implemented for the filter concept consists of a few steps. Some preliminary steps are a rigorous characterization of a double-ridge coaxial waveguide, and the modelling of an equivalent circuit model for the parallel coupled ridge waveguide devised in the filter concept. From these elements, a full wave electromagnetic analysis shows that parallel-coupled asymmetric ridge waveguides produce strongly dispersive coupling which introduces a transmission zero. Later on this property is extended to parallel-coupled asymmetric ridge waveguide resonators, where it is demonstrated that it is possible to independently control the coupling coefficient and the frequency of the transmission zero. This allows the realization of pseudo-elliptic narrowband in-line bandpass filters in E-plane technology. A general synthesis procedure for high order filters is outlined and numerical and experimental results are presented for validation. The elements employed for the synthesis procedure of the bandpass prototypes are also applied to investigate structures suitable for different applications. In particular, stopband and dual stopband filters are presented with numerical and experimental results. Finally, the study of a microwave chemical/biochemical sensing device for the characterization and detection of cells in chemical substances and cells in solution in micro-litre volumes is also reported.Engineering and Physical Sciences Research Council(EPSRC

Technologies for injection molded antennas for mass production

Tesi en modalitat de compendi de publicacions. In reference to IEEE copyrighted material which is used with permission in this thesis, the IEEE does not endorse any of Universitat Politècnica de Catalunya's products or services. Internal or personal use of this material is permitted. If interested in reprinting/republishing IEEE copyrighted material for advertising or promotional purposes or for creating new collective works for resale or redistribution, please go to http://www.ieee.org/publications_standards/publications/rights/rights_link.html to learn how to obtain a License from RightsLink.(English) The deployment of 5G antenna infrastructure and the mandatory adoption of anti-collision radars for automotive cars will require large amount of antennas operating in the millimeter and sub-millimeter wavelength. These antennas are usually arrays and the possibility to manufacture the antenna array including the feeding network and the radiating element as a plastic piece reducing the need to use large (Printed Circuit Boards) PCB’s on expensive dielectric substrates, can be an interesting manufacturing technology. In this regard, waveguide-based antennas can be assembled using plastic technology with a proper metallization procedure. They are more scalable in terms of efficiency than microstrip line (ML) antennas and as the number of antennas in the array increases the gain is not reduced due to the losses in the substrate. In this thesis, the industrial challenges of this technology are addressed. A detailed tolerance study by including the plastic manufacturing errors, typically +-0.1mm, is carried out in order to check the feasibility of plastic antennas to address mass production. The antennas will need to be integrated with the radar chipsets, so a transition between the chip and the waveguide-antennas will be presented. These transitions can act as a direct chip-waveguide launcher, potentially reducing the need of using large substrates, hence reducing the cost of the antenna. Also, the need to apply metal coating is also explored to achieve the desired performance. Conventional techniques such as copper electrodeposition is used. The main drawback is that the copper has a lot of difficulties depositing into right angle surfaces. Eventually, these antennas will have to be integrated in the aesthetics of a car, usually behind a plastic radome (with its respective manufacturing errors as well) that will need to be designed and optimized properly in order to introduce the minimum distorsions to the radar. Optimization based on simulators done with commercial electromagnetic softwares like CST is not feasible due to the required large computation time. In this regard an ad-hoc ray-tracing based simulator has been developed to asses radome induced errors in radar performance. All these industrial problems are taken into account from the design stage where the time, price, fabrication tolerances and radiation requirements have to be compromised at the same time increasing dramatically the design complexity.(Español) El despliegue de infraestructura de antenas 5G y la adopción obligatoria de radares anticolisión para automóviles requerirá una gran cantidad de antenas que operen en longitudes de onda milimétricas y submilimétricas. Estas antenas suelen ser agrupaciones y la posibilidad de fabricar la agrupación de antenas, incluida la red de alimentación y el elemento radiante como una pieza de plástico, lo que reduce la necesidad de usar PCB grandes (placas de circuito impreso) en sustratos dieléctricos costosos, puede ser una tecnología de fabricación interesante. En este sentido, las antenas basadas en guía de ondas se pueden ensamblar utilizando tecnología plástica con un procedimiento de metalización adecuado. Son más escalables en términos de eficiencia que las antenas de línea microstrip (ML) y, a medida que aumenta el número de antenas en el arreglo, la ganancia no se reduce debido a las pérdidas en el sustrato. En esta tesis se abordan los retos industriales de esta tecnología. Se lleva a cabo un estudio de tolerancia detallado que incluye los errores de fabricación de plástico, normalmente +- 0,1 mm, para comprobar la viabilidad de las antenas de plástico para hacer frente a la producción en masa. Las antenas deberán integrarse junto con los chips de radar, por lo que se presentará una transición entre el chip y las antenas de guía de ondas. Estas transiciones pueden actuar como una transición directa de chip-guía, lo que podría reducir la necesidad de usar sustratos grandes y, por lo tanto, reducir el costo de la antena. Además, también se explora la necesidad de aplicar un recubrimiento metálico para lograr el rendimiento deseado. Se utilizan técnicas convencionales como la electrodeposición de cobre. El principal inconveniente es que el cobre tiene muchas dificultades para depositarse en superficies en ángulo recto. Eventualmente, estas antenas deberán integrarse en la estética de un automóvil, generalmente detrás de un radomo de plástico (con sus respectivos errores de fabricación también) que deberá diseñarse y optimizarse adecuadamente para introducir las mínimas distorsiones al radar. La optimización basada en simuladores realizados con software electromagnético comercial como CST no es factible debido al gran tiempo de cálculo requerido. En este sentido, se ha desarrollado un simulador basado en trazado de rayos ad-hoc para evaluar los errores inducidos por el radomo en el rendimiento del radar. Todos estos problemas industriales se tienen en cuenta desde la etapa de diseño donde el tiempo, el precio, las tolerancias de fabricación y los requisitos de radiación tienen que verse comprometidos al mismo tiempo que aumentan drásticamente la complejidad del diseño.Postprint (published version

Nonlinear mechanisms in passive microwave devices

Premi extraordinari doctorat curs 2010-2011, àmbit d’Enginyeria de les TICThe telecommunications industry follows a tendency towards smaller devices, higher power and higher frequency, which imply an increase on the complexity of the electronics involved. Moreover, there is a need for extended capabilities like frequency tunable devices, ultra-low losses or high power handling, which make use of advanced materials for these purposes. In addition, increasingly demanding communication standards and regulations push the limits of the acceptable performance degrading indicators. This is the case of nonlinearities, whose effects, like increased Adjacent Channel Power Ratio (ACPR), harmonics, or intermodulation distortion among others, are being included in the performance requirements, as maximum tolerable levels. In this context, proper modeling of the devices at the design stage is of crucial importance in predicting not only the device performance but also the global system indicators and to make sure that the requirements are fulfilled. In accordance with that, this work proposes the necessary steps for circuit models implementation of different passive microwave devices, from the linear and nonlinear measurements to the simulations to validate them. Bulk acoustic wave resonators and transmission lines made of high temperature superconductors, ferroelectrics or regular metals and dielectrics are the subject of this work. Both phenomenological and physical approaches are considered and circuit models are proposed and compared with measurements. The nonlinear observables, being harmonics, intermodulation distortion, and saturation or detuning, are properly related to the material properties that originate them. The obtained models can be used in circuit simulators to predict the performance of these microwave devices under complex modulated signals, or even be used to predict their performance when integrated into more complex systems. A key step to achieve this goal is an accurate characterization of materials and devices, which is faced by making use of advanced measurement techniques. Therefore, considerations on special measurement setups are being made along this thesis.Award-winningPostprint (published version