Downloaded from orbit.dtu.dk on: Jan 17, 2023 EMC, RF, and Antenna Systems in Miniature Electronic Devices Ruaro, Andrea Publication date: 2016 Document Version Publisher's PDF, also known as Version of record Link back to DTU Orbit Citation (APA): Ruaro, A. (2016). EMC, RF, and Antenna Systems in Miniature Electronic Devices. Technical University of Denmark, Department of Electrical Engineering. 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EMC, RF, and Antenna Systems in Miniature Electronic Devices Ph.D. Thesis Andrea Ruaro January 2016 The present work was carried out at GN ReSound A/S (place of employment) and at DTU Electrical Engineering in partial fulfilment of the requirements for the Ph.D. degree from the Technical University of Denmark. Supervisors: Kaj Bjarne Jakobsen, Ph.D. Electromagnetic Systems, DTU Elektro, Technical University of Denmark Jesper Thaysen, Ph.D. GN ReSound A/S The well in which Truth is said to reside is really a bottomless pit. – Oliver Heaviside, in Electromagnetic Theory, 1893. i Abstract Advanced techniques for the control of electromagnetic interference (EMI) and for the optimization of the electromagnetic compatibility (EMC) perfor- mancehasbeendevelopedundertheconstraintstypicalofminiatureelectronic devices (MED). The electromagnetic coexistence of multiple systems and their mutual interaction have been the underlying theme of the work. The research results concern different aspects related to the integration of radio-frequency (RF) electronics in MEDs and hearing instruments (HI). To control internal EMI, a novel near-field parasitic resonator (NFPR) has beenresearched. Thestructureallowsforeffectivesuppressionofradiationfrom the MED, while taking into consideration the integration and miniaturization aspects. To increase the sensitivity of the system, a compact LNA suitable for on-body applications has been developed. The LNA allows for an increase in the overall sensitivity of a system comprised of two HIs communicating among them. To optimize the on-body and off-body communication links of HIs, a novel wearableantennawasdesigned. Thedesignoriginatesfromconsiderationsabout the EM environment where the antenna operates. An EMC-robust alternative to the on-body link was investigated through the use of body-coupled commu- nications (BCC) and integrated with the antenna in a unique system. Overall, the novel researched solutions effectively addressed a set of intra- andinter-systemEMIandEMCissues,asdictatedbythecomplexityofemerg- ing modern miniature electronics. iii Resum´e Avancerede teknikker til reduktion af elektromagnetisk interferens (EMI) og optimering af elektromagnetisk kompatibilitet (EMC) er udviklet under de begrænsninger,somertypiskforminiaturiseretelektroniskudstyr(MED).Den elektromagnetiskesameksistensaffleresystemerogderesindbyrdessamspil,har væretdetunderliggendeemnefordettearbejde.Forskningsresultaternevedrører forskellige aspekter relateret til integrationen af radiofrekvenselektronik (RF- elektronik) i MED og høreapparater (HI). For at kunne kontrollere den interne EMI, er en nærfeltsparasitresonator (NFPR)blevetudforsket.Strukturentilladereffektivtundertrykkelseafstr˚alingen fra MED, idet der tages hensyn til integrations- og miniaturiseringsaspekter. Foratøgesystemfølsomheden,erderudvikletenkompaktLNA,derervelegnet til p˚a-kroppen-applikationer. LNAen giver mulighed for at forøge den samlede følsomhed af systemet, der best˚ar af to høreapparater, der kommunikerer med hinanden. For at optimere p˚a-krop og ud-af-krop kommunikationsforbindelsen, er der designet en ny bærbar antenne. Designet hidrører fra overvejelser om det elek- tromagnetisk miljø, hvori antennen skal fungere. Et EMC-stærk alternativ til etlinkp˚akroppen,erblevetundersøgtvedbrugafkropskobletkommunikation (BCC), der er integreret med antennen til et unikt system. Samletsetadressererdenyeforskningsløsningereffektivtetsætafintra-og intersystemEMI-ogEMC-problemer,somdikteresafkompleksitetenafmoder- ne miniaturiseret elektronik. v Sommario Tecnicheavanzateperilcontrollodelleinterferenzeelettromagnetiche(EMI) e per l’ottimizzazione della compatibilita` elettromagnetica (EMC) sono state studiate sotto i vincoli caratteristici dei dispositivi elettronici miniaturizzati (MED). La coesistenza elettromagnetica di diversi sistemi e la loro interazio- ne reciproca sono stati i temi sottostanti del lavoro. I risultati della ricerca riguardanodiversiaspettidell’integrazionedielettronicaaradiofrequenza(RF) in dispositivi miniaturizzati e apparecchi acustici (HI). La ricerca esamina una nuova struttura, cio`e un risuonatore parassita (NF- PR)postoinprossimit`adiunasorgenteelettromagnetica,percontrollarel’inter- ferenzainterna. Lastrutturapermettelasoppressioneeffettivadellaradiazione generata in un dispositivo, tenendo conto degli aspetti di integrazione e mi- niaturizzazione dell’elettronica. Un compatto amplificatore a bassa figura di rumore(LNA)adattoperapplicazioniindossabili`esviluppatopermigliorarela sensibilita` del circuito radio. L’amplificatore permette un miglioramento della sensibilita` complessiva di un sistema composto da due apparecchi acustici che comunicano tra loro. Una nuova antenna, adatta ad essere indossata, `e stata progettata per ot- timizzare i collegamenti radio degli apparecchi acustici. Il concetto`e sviluppa- to a partire da considerazioni sull’ambiente elettromagnetico in cui l’antenna si trova ad operare. Un collegamento radio alternativo, robusto da una pro- spettiva di compatibilita` elettromagnetica, `e stato studiato attraverso l’uso di comunicazioni intra-corpo e integrato con l’antenna in un unico sistema. Nel complesso, le nuovi soluzioni studiate affrontano con efficacia una serie di problemi di EMI e EMC, sia interni all’elettronica che riguardanti l’intera- zioneconaltridispositivi,chestannoemergendoacausadellacomplessita`della moderna elettronica in miniatura. vii