Antenna mutual coupling and amplifier effects in transmission

Veli-Pekka Kutinlahti

Antenna mutual coupling and amplifier effects in transmission

Julkaisun otsikon käännös: Antennien keskinäiskytkentä ja vahvistimen ilmiöt lähetyksessä

Veli-Pekka Kutinlahti

Elektroniikan ja nanotekniikan laitos

Tutkimustuotos: Doctoral Thesis › Collection of Articles

Abstrakti

Viidennen sukupolven (5G) telekommunikaatiostandardi käyttää moniantennijärjestelmiä mahdollistaakseen monitulo ja -lähtö- sekä keilankääntökyvykkyydet useimpiin langattomiin laitteisiin. Jopa kannettavat laitteet tullaan varustamaan näillä järjestelmillä. Tämä muuttaa lähetinvastaanotinten arkkitehtuuria, koska jokainen antennielementti tulee varustaa omalla syötönohjauksella, johon kuuluu vahvistin ja vaiheensiirrin. Näiden laitteiden korkea integraatio estää ferriittisten isolaattorien käytön laitteiden välissä, minkä takia aktiiviset heijastukset antenneista vahvistimien ulostuloihin luovat järjestelmään epäideaalisuuksia. Vahvistimen kuormaimpedanssin siirtyminen aiheuttaa muutoksia vahvistimen lähtötehossa, lineaarisuudessa sekä hyötysuhteessa ja voi pahimmillaan aiheuttaa laitteiden rikkoutumisia. Tämän kehityksen rinnalla 5G käyttää korkeamman taajuuden ja laajemman kaistanleveyden signaaleja, mikä ohjaa kehittämään uusia suunnittelumenetelmiä laajakaistaisille korkean suuntaavuden antenneille, jotka kykenevät keilankääntöön. Työn ensimmäinen osa käsittelee erilaisten ominaisuuksien optimointia vahvistinantennijärjestelmissä, joissa esiintyy keskinäiskytkennän aiheuttamaa epäsovitusta. Ensimmäisenä ekvivalenttinen isotrooppinen säteilyteho (EIRP) optimoidaan vahvistinantennijärjestelmässä vaihesäädöllä 2x2 mikroliuska-antenniryhmässä. Vaihesäädöllä saavutetaan korkeimmillaan 0.7 dB EIRP parannus puolentehon keilankääntöalueella 2.5 GHz taajuudella verrattaessa progressiiviseen vaiheensiirtoon. Toisena kolmannen asteen intermodulaatio minimoidaan suhteessa kantotaajuuteen kaksitaajuisessa 1x4 vahvistinantennryhmässä, jossa molempien taajuuksien keiloja käännetään itsenäisesti, säätämällä syöttötehoja ja -vaiheita. Optimointi saavuttaa 25 dB parannuksen signaalin suhteessa kolmannen asteen intermodulaatioon ilman pääkeilojen tehotiheyden alenemista. Keilojen eheys kuitenkin kärsii sivukeilatasojen nousun muodossa. Kolmantena kolmannen asteen intermodulaatio suhteessa kantotaajuuteen minimoidaan antennisovituksella käyttäen vahvistimen ja antennin yhteissimulaatioita. Työn toinen osa käsittelee realisoidun vahvistuksen parantamista antenniryhmissä. Ensiksi tarkastellaan antenniryhmää, jota syötetään elementtikohtaisesti vahvistimilla, joiden ulostulon impedanssi vaihtelee. Muutos vahvistimen ulostuloimpedanssissa johtaa suurentuneeseen epäsovitukseen antennin sisääntulossa. Esitelty iteratiivinen menetelmä, joka ottaa huomioon impedanssin muutoksen, kykenee parantamaan realisoitua vahvistusta. Toiseksi esitellään klusteriryhmä saavuttamaan korkea vahvistuksen kattavuus laajemmalla taajuuskaistalla verrattaessa yksinkertaiseen identtisistä elementeistä koostuvaan mikroliuska-antenniryhmään. Klusteriryhmä hyödyntää mikroliuskaelementtejä eri resonanssitaajuksilla ja korkeaa keskinäistä kytkentää laajakaistaisen sovittamisen saavuttamiseksi syöttökertoimien säädöllä.

Julkaisun otsikon käännös	Antennien keskinäiskytkentä ja vahvistimen ilmiöt lähetyksessä
Alkuperäiskieli	Englanti
Pätevyys	Tohtorintutkinto
Myöntävä instituutio	Aalto-yliopisto
Valvoja/neuvonantaja	Viikari, Ville, Vastuuprofessori Lehtovuori, Anu, Ohjaaja
Kustantaja	Aalto University
Painoksen ISBN	978-952-64-1755-4
Sähköinen ISBN	978-952-64-1756-1
Tila	Julkaistu - 2024
OKM-julkaisutyyppi	G5 Artikkeliväitöskirja

Tutkimusalat

antenni
keilankääntö
keskinäiskytkentä
kuormanveto
vahvistin

Pääsy asiakirjaan

http://urn.fi/URN:ISBN:978-952-64-1756-1

Aalto Electronics-ICT
Ryynänen, J. (Manager)
Elektroniikan ja nanotekniikan laitos
Laitteistot/tilat: Facility

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@phdthesis{6eb2cb54a8bd4894a3c6923766331b66,

title = "Antenna mutual coupling and amplifier effects in transmission",

abstract = "The oncoming fifth generation (5G) telecommunication standard utilizes multi-antenna systems to implement multiple-input multiple-output and beam-steering capabilities in most wireless devices, including mobile devices. This shift in transceiver architecture will introduce each antenna element with its own feed control, along with an amplifier and phase shifter chain. The high integration level of these components prohibits the use of traditional ferrite circulators as isolators between the components, introducing the non-ideality of active reflections in the antenna elements to the amplifier outputs. The change in amplifier load impedance causes variation in amplifier output power, linearity, efficiency and can possibly even cause breakage of components in extreme cases. This development is parallel to the fact that 5G will use higher frequencies and wider bandwidth signals, driving the development of innovative design methods to achieve wide-band high-gain antennas with beam-steering capability. The first part of the thesis describes optimizing different aspects of amplifier-antenna systems with mutual-coupling-induced mismatch. First, the equivalent isotropic radiated power (EIRP) of a 2x2 patch antenna array in an amplifier-antenna system is optimized through phase tuning. Phase tuning achieves a maximum 0.7-dB improvement in EIRP within the -3-dB beam steer range at 2.5 GHz, compared to progressive phase shift. Second, the 3rd order intermodulation is minimized with respect to the carrier by adjusting input feed power and phase in a two-tone excited 1x4 amplifier-antenna array, where the beam at each tone is independently steered. Optimization results in a 25-dB improvement in the signal-to-3rd-order-intermodulation ratio without decreasing far-field power density. However, this improvement comes at the cost of sacrificing beam integrity in terms of side-lobe level. Third, 3rd order intermodulation with respect to the carrier is minimized by antenna impedance matching using co-simulations of the amplifier and antenna. The second part considers the optimization of realized gain in antenna arrays. First, an antenna array driven with element-specific amplifiers with varying output impedance is examined. Changes in amplifier gain may lead to altered output impedance and increased mismatch in the antenna interface, a phenomenon often neglected. An iterative method that accounts for the change in impedance is introduced, resulting in increased realized gain. Second, a cluster array concept is proposed to achieve high coverage gain over a wider band compared to a simple patch antenna array with similar elements. The cluster array utilizes patch elements with different resonant frequencies and high inter-element coupling to achieve wide-band matching with feeding weight tuning.",

keywords = "amplifier, antenna, beam-steering, load-pull, mutual coupling, antenni, keilank{\"a}{\"a}nt{\"o}, keskin{\"a}iskytkent{\"a}, kuormanveto, vahvistin, amplifier, antenna, beam-steering, load-pull, mutual coupling",

author = "Veli-Pekka Kutinlahti",

year = "2024",

language = "English",

isbn = "978-952-64-1755-4",

series = "Aalto University publication series DOCTORAL THESES",

publisher = "Aalto University",

number = "73",

address = "Finland",

school = "Aalto University",

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TY - BOOK

T1 - Antenna mutual coupling and amplifier effects in transmission

AU - Kutinlahti, Veli-Pekka

PY - 2024

Y1 - 2024

N2 - The oncoming fifth generation (5G) telecommunication standard utilizes multi-antenna systems to implement multiple-input multiple-output and beam-steering capabilities in most wireless devices, including mobile devices. This shift in transceiver architecture will introduce each antenna element with its own feed control, along with an amplifier and phase shifter chain. The high integration level of these components prohibits the use of traditional ferrite circulators as isolators between the components, introducing the non-ideality of active reflections in the antenna elements to the amplifier outputs. The change in amplifier load impedance causes variation in amplifier output power, linearity, efficiency and can possibly even cause breakage of components in extreme cases. This development is parallel to the fact that 5G will use higher frequencies and wider bandwidth signals, driving the development of innovative design methods to achieve wide-band high-gain antennas with beam-steering capability. The first part of the thesis describes optimizing different aspects of amplifier-antenna systems with mutual-coupling-induced mismatch. First, the equivalent isotropic radiated power (EIRP) of a 2x2 patch antenna array in an amplifier-antenna system is optimized through phase tuning. Phase tuning achieves a maximum 0.7-dB improvement in EIRP within the -3-dB beam steer range at 2.5 GHz, compared to progressive phase shift. Second, the 3rd order intermodulation is minimized with respect to the carrier by adjusting input feed power and phase in a two-tone excited 1x4 amplifier-antenna array, where the beam at each tone is independently steered. Optimization results in a 25-dB improvement in the signal-to-3rd-order-intermodulation ratio without decreasing far-field power density. However, this improvement comes at the cost of sacrificing beam integrity in terms of side-lobe level. Third, 3rd order intermodulation with respect to the carrier is minimized by antenna impedance matching using co-simulations of the amplifier and antenna. The second part considers the optimization of realized gain in antenna arrays. First, an antenna array driven with element-specific amplifiers with varying output impedance is examined. Changes in amplifier gain may lead to altered output impedance and increased mismatch in the antenna interface, a phenomenon often neglected. An iterative method that accounts for the change in impedance is introduced, resulting in increased realized gain. Second, a cluster array concept is proposed to achieve high coverage gain over a wider band compared to a simple patch antenna array with similar elements. The cluster array utilizes patch elements with different resonant frequencies and high inter-element coupling to achieve wide-band matching with feeding weight tuning.

AB - The oncoming fifth generation (5G) telecommunication standard utilizes multi-antenna systems to implement multiple-input multiple-output and beam-steering capabilities in most wireless devices, including mobile devices. This shift in transceiver architecture will introduce each antenna element with its own feed control, along with an amplifier and phase shifter chain. The high integration level of these components prohibits the use of traditional ferrite circulators as isolators between the components, introducing the non-ideality of active reflections in the antenna elements to the amplifier outputs. The change in amplifier load impedance causes variation in amplifier output power, linearity, efficiency and can possibly even cause breakage of components in extreme cases. This development is parallel to the fact that 5G will use higher frequencies and wider bandwidth signals, driving the development of innovative design methods to achieve wide-band high-gain antennas with beam-steering capability. The first part of the thesis describes optimizing different aspects of amplifier-antenna systems with mutual-coupling-induced mismatch. First, the equivalent isotropic radiated power (EIRP) of a 2x2 patch antenna array in an amplifier-antenna system is optimized through phase tuning. Phase tuning achieves a maximum 0.7-dB improvement in EIRP within the -3-dB beam steer range at 2.5 GHz, compared to progressive phase shift. Second, the 3rd order intermodulation is minimized with respect to the carrier by adjusting input feed power and phase in a two-tone excited 1x4 amplifier-antenna array, where the beam at each tone is independently steered. Optimization results in a 25-dB improvement in the signal-to-3rd-order-intermodulation ratio without decreasing far-field power density. However, this improvement comes at the cost of sacrificing beam integrity in terms of side-lobe level. Third, 3rd order intermodulation with respect to the carrier is minimized by antenna impedance matching using co-simulations of the amplifier and antenna. The second part considers the optimization of realized gain in antenna arrays. First, an antenna array driven with element-specific amplifiers with varying output impedance is examined. Changes in amplifier gain may lead to altered output impedance and increased mismatch in the antenna interface, a phenomenon often neglected. An iterative method that accounts for the change in impedance is introduced, resulting in increased realized gain. Second, a cluster array concept is proposed to achieve high coverage gain over a wider band compared to a simple patch antenna array with similar elements. The cluster array utilizes patch elements with different resonant frequencies and high inter-element coupling to achieve wide-band matching with feeding weight tuning.

KW - amplifier

KW - antenna

KW - beam-steering

KW - load-pull

KW - mutual coupling

KW - antenni

KW - keilankääntö

KW - keskinäiskytkentä

KW - kuormanveto

KW - vahvistin

KW - amplifier

KW - antenna

KW - beam-steering

KW - load-pull

KW - mutual coupling

M3 - Doctoral Thesis

SN - 978-952-64-1755-4

T3 - Aalto University publication series DOCTORAL THESES

PB - Aalto University

ER -

Antenna mutual coupling and amplifier effects in transmission

Abstrakti

Tutkimusalat

Pääsy asiakirjaan

Sormenjälki

Laitteet

Aalto Electronics-ICT

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