A calibration free vector network analyzer

Recently, two novel single-port, phase-shifter based vector network analyzer (VNA) systems were developed and tested at X-band (8.2 - 12.4 GHz) and Ka-band (26.4 - 40 GHz), respectively. These systems operate based on electronically moving the standing wave pattern, set up in a waveguide, over a Schottky detector and sample the standing wave voltage for several phase shift values. Once this system is fully characterized, all parameters in the system become known and hence theoretically, no other correction (or calibration) should be required to obtain the reflection coefficient, (Γ), of an unknown load. This makes this type of VNA calibration free which is a significant advantage over other types of VNAs. To this end, a VNA system, based on this design methodology, was developed at X-band using several design improvements (compared to the previous designs) with the aim of demonstrating this calibration-free feature. It was found that when a commercial VNA (HP8510C) is used as the source and the detector, the system works as expected. However, when a detector is used (Schottky diode, log detector, etc.), obtaining correct Γ still requires the customary three-load calibration. With the aim of exploring the cause, a detailed sensitivity analysis of prominent error sources was performed. Extensive measurements were done with different detection techniques including use of a spectrum analyzer as power detector. The system was tested even for electromagnetic compatibility (EMC) which may have contributed to this issue. Although desired results could not be obtained using the proposed standing-wave-power measuring devices like the Schottky diode but the principle of calibration-free VNA was shown to be true --Abstract, page iii

Design and implementation of a compact Vector Network Analyzer

Vector Network Analyzers (VNAs) are extensively used in Radio Frequency circuit design to characterize RF components and systems. They are also used for materials characterization, as analyzing the purity of petroleum or for detecting skin tumors. These instruments perform the measurement of the S-parameters, which are used to describe the electrical behavior of linear electrical networks. In this project we are developing a miniature device that can be connected to a smartphone. Together, our device and the smartphone can provide some basic VNA features. The device will be in charge of the RF signals generation and detection, while the phone will be used to provide a User Interface (making use of its touch screen) and data processing. This new device would be of great importance in applications that require high mobility, as system¿s validation in difficult locations (for example an antenna located on the top of a tower); it can also be of great use in education, because it would be a cheap instrument that could be used in university laboratories or high schools. In research it could be used in portable medical instruments and, finally, radio amateurs could have a great and affordable tool to use in their home projects. This project has been carried out within the van der Weide research group at the College of Engineering of the University of Wisconsin ¿ Madison.Martínez Argudo, M. (2014). Design and implementation of a compact Vector Network Analyzer. http://hdl.handle.net/10251/34999.Archivo delegad

CIRCUIT MODULES FOR BROADBAND CMOS SIX-PORT SYSTEMS

This dissertation investigates four circuit modules used in a CMOS integrated six-port measurement system. The first circuit module is a wideband power source generator, which can be implemented with a voltage controlled ring oscillator. The second circuit module is a low-power 0.5 GHz - 20.5 GHz power detector with an embedded amplifier and a wideband quasi T-coil matching network. The third circuit module is a six-port circuit, which can be implemented with distributed or lumped- lement techniques. The fourth circuit module is the phase sifter used as calibration loads. The theoretical analysis, circuit design, simulated or experimental verifications of each circuit module are also included

Study of quasi-optical circuit techniques in varactor multipliers

Quasi-optical circuit techniques in varactor multiplier

Modifying design of four-port couplers for enhanced six-port reflectometer performance

Ph.DDOCTOR OF PHILOSOPH

Simultaneous Data Communication and Power Transfer Technique with Multiport Interferometric Receiver

RÉSUMÉ Le problème de la communication est généralement présenté comme un problème de trans-mission d’un message généré d’un point a un autre. Certains systèmes de communication modernes sou˙rent de contraintes énergétiques sévères. Avec le développement rapide des systèmes électroniques sans fil de faible puissance, d’innombrables activités de recherche ont été menées en vue d’explorer la faisabilité d’une alimentation à distance ou sans fil de ces systèmes. Par conséquent, la transmission d’énergie sans fil (WPT) est en cours de développe-ment en tant que technique prometteuse pour alimenter des appareils électroniques à distance et pour prolonger la durée de vie des réseaux sans fil à contrainte d’énergie. Parmi les éner-gies renouvelables récoltées dans l’environnement, les signaux RF rayonnés par les émetteurs peuvent être une ressource viable pour le transfert d’énergie sans fil, tandis que les signaux RF ont été largement utilisés comme véhicule pour la transmission d’informations sans fil (WIT). Par conséquent, le transfert simultané d’informations et la plateforme de transfert de puissance sans fil (SWIPT) deviennent bénéfiques, car il réalise les deux utilisations utiles des signaux RF en même temps et il o˙re ainsi potentiellement une grande commodité aux utilisateurs mobiles. L’antenne redresseuse, qui combine des fonctionnalités du redresseur et de l’antenne, est un élément clé pour la transmission et la récolte d’énergie sans fil. L’eÿcacité de conversion du circuit de redressement détermine les performances globales de l’antenne redresseuse. Par conséquent, pour concevoir une antenne redresseuse à haute eÿcacité qui peut garantir la qualité d’un système WPT, il convient de se concentrer davantage sur l’investigation, l’analyse et le développement de redresseurs axés sur les performances en référence à une eÿcacité de conversion radio fréquence à courant continu. D’un autre côté, les circuits redresseurs peuvent simplement récupérer l’énergie et ils ne peuvent pas décoder le signal transmis pour fins de communication. Cependant, la transmission de données est une exigence essentielle des systèmes de communication sans fil. Par conséquent, si la capacité de détection et de traitement du signal peut être ajoutée à une architecture antenne redresseuse, un récepteur avec transmission de puissance sans fil et communication de données simultanées peut être réalisé. Ce mémoire vise à étudier et à démontrer un récepteur de multifonction et de multiport qui a la capacité de collecter simultanément l’énergie sans fil et les données de communication fonctionnant à la fréquence des microondes.----------ABSTRACT The problem of communication is usually cast as one of transmitting a message generated at one point to another point. Some modern communication systems are known to suffer from severe energy constraints and power consumptions. With the rapid development of low power wireless electronic systems, countless research activities have been carried out to explore the feasibility of a remote or wireless powering of those systems. Therefore, wireless power transmission (WPT) is being developed as a promising technique, for powering electronic devices over distance and for prolonging the lifetime of energy constrained wireless networks. Among the renewable energy harvested from the environment, the RF signals radiated by transmitters can be a viable resource for wireless power transfer, while RF signals have been widely used as a vehicle for wireless information transmission (WIT). Therefore, simultaneous wireless information and power transfer (SWIPT) platform becomes appealing since it realizes both useful utilizations of RF signals at the same time, and thus potentially offers great convenience to mobile users. The rectenna, combining the functionalities of rectifier and antenna, is a key element for wireless power transmission and harvesting. The conversion efficiency of the rectifying circuit determines the overall performance of the rectenna. Therefore, to design a high-efficiency rectenna that can guarantee the quality of a WPT system, more focus should be concentrated on the investigation, analysis and development performance-driven rectifiers with reference to high RF-to-DC conversion efficiency. On the other hand, rectenna circuits can just scavenge energy and they cannot decode the transmitted signal for communication purpose. How-ever, the data transmission is an essential requirement of wireless communication systems. Therefore, if the ability of signal detection and processing can be added to a rectenna architecture then a multi-function receiver with simultaneous wireless power transmission and data communication can be realized.This dissertation aims to investigate and demonstrate a multi-function and multi-port receiver with the capability of simultaneous wireless energy harvesting and data communication operating at microwave frequency. To achieve these goals, it becomes interesting when a single receiver chain is able to convert the RF power to DC power, while at the same time converting the RF modulated signal to BaseBand (BB) signal. Therefore, the fundamental methodology to receive and convert the RF signal to BB while simultaneously harvesting power is derived and analyzed in this work

Analysis and synthesis of six-port modulators

Ph.DDOCTOR OF PHILOSOPH