This thesis considers integration of antennas and active electronics manufactured on the same substrate. The main topic is on-chip antennas for commercial silicon processes, but hybrid integration using printed circuit board technology is also addressed. The possible use of micromachining techniques as a means of reducing substrate losses of antennas manufactured on low resistivity silicon wafers is investigated. Compact dipole, loop, and inverted-F antennas for the 20-40 GHz frequency range are designed, implemented, and characterized. The results show significantly improved antenna efficiency when micromachining is used as a post-processing step for on-chip antennas manufactured in silicon technology. High resistivity wafers are used in a commercial silicon germanium technology to improve the efficiency of dipole antennas realized using the available circuit metal layers in the process. Monolithically integrated 24 GHz receivers with on-chip antennas are designed and evaluated with regard to antenna and system performance. No noticeable degradation of the receiver performance caused by cross talk between the antenna and the integrated circuit is observed. For low frequency antenna arrays, such as base station antennas, hybrid integration of active devices within the antenna aperture is treated. A compact varactor based phase shifter for traveling wave antenna applications is proposed and evaluated. Electrically steerable traveling wave patch antenna arrays, with the phase shifters implemented in the same conductor layer as the radiating elements, are designed and manufactured in microstrip technology. It is experimentally verified that the radiation from the feed network and phase shifters in the proposed antenna configuration is small.

Abstract In this thesis, bandwidth (BW) enhanced antennas for mobile terminals and multilayer ceramic packages are presented. The thesis is divided into two parts. In the first part, electrically frequency-tunable mobile terminal antennas have been studied. The first three antennas presented were of a dual-band planar inverted-F type (PIFA) and were tuned to operate in frequency bands appropriate to the GSM850 (824–894 MHz), GSM900 (880–960 MHz), GSM1800 (1710–1880 MHz), GSM1900 (1850–1990 MHz) and UMTS (1920–2170 MHz) cellular telecommunication standards with RF PIN diode switches. The first antenna utilized a frequency-tuning method developed in this thesis. The method was based on an integration of the tuning circuitry into the antenna. The tuning of the second antenna was based on a switchable parasitic antenna element. By combining the two frequency-tuning approaches, a third PIFA could be switched to operate in eight frequency bands. The planar monopole antennas researched were varactor-tunable for digital television signal reception (470–702 MHz) and RF PIN diode switchable dual-band antenna for operation at four cellular bands. The key advantage of the former antenna was a compact size (0.7 cm3), while for the latter one, a tuning circuit was implemented without using separate DC wiring for controlling the switch component. The second part of the thesis is devoted to multilayer ceramic package integrated microwave antennas. In the beginning, the use of a laser micro-machined embedded air cavity was proposed to enable antenna size to impedance bandwidth (BW) trade-off for a microwave microstrip in a multilayer monolithic ceramic media. It was shown that the BW of a 10 GHz antenna fabricated on a low temperature co-fired ceramic (LTCC) substrate could be doubled with this technique. Next, the implementation of a compact surface mountable LTCC antenna package operating near 10 GHz was described. The package was composed of a BW optimized stacked patch microstrip antenna and a wide-band vertical ball grid array (BGA)-via interconnection. Along with the electrical performance optimization, an accurate circuit model describing the antenna structure was presented. Finally, the use of low-sintering temperature non-linear dielectric Barium Strontium Titanate (BST) thick films was demonstrated in a folded slot antenna operating at 3 GHz and frequency-tuned with an integrated BST varactor.

No / To mitigate potential interferences with coexisting wireless systems operating over 3.3-3.6 GHz, 5.15-5.35 GHz, or 5.725-5.825 GHz bands, four novel band-notched antennas suitable for ultra-wideband (UWB) applications are proposed. These include UWB antennas with a single wide notched band, a single narrow notched band, dual notched bands, and triple notched bands. Each antenna comprises a half-circle shaped patch with an open rectangular slot and a half-circle shaped ground plane. Good band-notched performance is achieved by using high permittivity and low dielectric loss substrate, and inserting quarter-wavelength horizontal/vertical stubs or alternatively embedding quarter-wavelength open-ended slots within the feed line. The results of both simulation and measurement confirm that the gain suppression of the single and multiple band-notched antennas in each desired notched band are over 15 dB and 10 dB, respectively. The radiation pattern of the proposed triple band-notched design is relatively stable across the operating frequency band.

The studies in this dissertation mainly utilize planar antennas for ultra-wideband antenna designs not only on the investigation of antenna performance but also towards exploiting attractive features of ultra-wideband antennas for practical applications, such as WMAN access-point antennas, omnidirectional WiMAX access-point antennas, band-notched UWB (Ultra-wideband, 3.1 ~ 10.6 GHz) antennas, and so on. To begin with, the effects of the ground-plane size and the asymmetrical ground plane on ultra-wideband antennas are studied in Chapter 2. Following up, from the conclusive results, an antenna for WMAN operation in access-point applications and an omnidirectional monopole for USB wireless network card device are proposed and analyzed. Characteristics of ultra-wideband antenna radiation in relation to the antenna's width for obtaining omnidirectional radiation are addressed. In Chapter 3, several ultra-wideband access-point antennas are presented for achieving good omnidirectional radiation in the azimuthal plane across the bandwidth. Furthermore, in Chapter 4, band-notching techniques are applied to ultra-wideband antennas for avoiding the interference between the UWB and the WLAN systems.

Made available in DSpace on 2014-12-17T14:55:12Z (GMT). No. of bitstreams: 1 HumbertoDA_TESE.pdf: 4762435 bytes, checksum: 20aae983d6895db90a85b0e2b107200f (MD5) Previous issue date: 2013-09-02 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In the globalized world modern telecommunications have assumed key role within the company, causing a large increase in demand for the wireless technology of communication, which has been happening in recent years have greatly increased the number of applications using this technology. Due to this demand, new materials are developed to enable new control mechanisms and propagation of electromagnetic waves. The research to develop new technologies for wireless communication presents a multidisciplinary study that covers from the new geometries for passive antennas, active up to the development of materials for devices that improve the performance at the frequency range of operation. Recently, planar antennas have attracted interest due to their characteristics and advantages when compared with other types of antennas. In the area of mobile communications the need for antennas of this type has become increasingly used, due to intensive development, which needs to operate in multifrequency antennas and broadband. The microstrip antennas have narrow bandwidth due to the dielectric losses generated by irradiation. Another limitation is the degradation of the radiation pattern due to the generation of surface waves in the substrate. Some techniques have been developed to minimize this limitation of bandwidth, such as the study of type materials PBG - Photonic Band Gap, to form the dielectric material. This work has as main objective the development project of a slot resonator with multiple layers and use the type PBG substrate, which carried out the optimization from the numerical analysis and then designed the device initially proposed for the band electromagnetic spectrum between 3-9 GHz, which basically includes the band S to X. Was used as the dielectric material RT/Duroid 5870 and RT/Duroid 6010.LM where both are laminated ceramic-filled PTFE dielectric constants 2.33 and 10.2, respectively. Through an experimental investigation was conducted an analysis of the simulated versus measured by observing the behavior of the radiation characteristics from the height variation of the dielectric multilayer substrates. We also used the LTT method resonators structures rectangular slot with multiple layers of material photonic PBG in order to obtain the resonance frequency and the entire theory involving the electromagnetic parameters of the structure under consideration. xviii The analysis developed in this work was performed using the method LTT - Transverse Transmission Line, in the field of Fourier transform that uses a component propagating in the y direction (transverse to the real direction of propagation z), thus treating the general equations of the fields electric and magnetic and function. The PBG theory is applied to obtain the relative permittivity of the polarizations for the sep photonic composite substrates material. The results are obtained with the commercial software Ansoft HFSS, used for accurate analysis of the electromagnetic behavior of the planar device under study through the Finite Element Method (FEM). Numerical computational results are presented in graphical form in two and three dimensions, playing in the parameters of return loss, frequency of radiation and radiation diagram, radiation efficiency and surface current for the device under study, and have as substrates, photonic materials and had been simulated in an appropriate computational tool. With respect to the planar device design study are presented in the simulated and measured results that show good agreement with measurements made. These results are mainly in the identification of resonance modes and determining the characteristics of the designed device, such as resonant frequency, return loss and radiation pattern / No mundo globalizado moderno, as telecomunica??es assumiram um papel fundamental dentro das sociedades, provocando um grande aumento da demanda por tecnologia de comunica??o sem fio, isto vem acontecendo nos ?ltimos anos e tem aumentado bastante o n?mero de aplica??es que utilizam esta tecnologia. Em decorr?ncia dessa demanda, novos materiais s?o desenvolvidos no sentido de possibilitar novos mecanismos de controle e propaga??o de ondas eletromagn?ticas. A pesquisa para o desenvolvimento de novas tecnologias para comunica??o sem fios apresenta um car?ter multidisciplinar que abrange desde o estudo de novas geometrias para antenas passivas e ativas at? o de desenvolvimento de materiais para dispositivos que melhorem o desempenho naquela faixa de frequ?ncia de opera??o. Recentemente as antenas planares tem despertado interesses devido as suas caracter?sticas e vantagens que oferecem quando comparadas com os demais tipos de antenas. Na ?rea de comunica??es m?veis a necessidade de antenas desse tipo tem se tornado cada vez maior, devido ao seu intenso desenvolvimento, que necessita de antenas que operem em multifrequ?ncia e em banda larga. As antenas de microfita apresentam largura de banda estreita devido ?s perdas no diel?trico geradas pela irradia??o. Outra limita??o ? a degrada??o do diagrama de irradia??o devido ? gera??o de ondas de superf?cie no substrato. Algumas t?cnicas est?o sendo desenvolvidas para minimizar esta limita??o de banda, como ? o caso do estudo de materiais do tipo PBG Photonic Band Gap, para compor o material diel?trico. Este trabalho tem como objetivo principal o desenvolvimento do projeto de um ressoador de fenda com m?ltiplas camadas e com a utiliza??o de substrato do tipo PBG, onde foi realizada a otimiza??o a partir da analise num?rica e em seguida, projetado o dispositivo proposto inicialmente para a faixa do espectro eletromagn?tico compreendida entre 3-9 GHz, que inclui basicamente a banda S at? X. Foi utilizado como material diel?trico o RT/Duroid 5870 e RT/Duroid 6010.2LM onde ambos s?o laminados cer?micos PTFE com constantes diel?tricas de 2.33 e 10.2, respectivamente. Atrav?s de uma investiga??o experimental foi realizada uma an?lise dos resultados simulados versus medidos observando o comportamento das xvi caracter?sticas de radia??o a partir da varia??o da altura das multicamadas de subtrato diel?trico. Foi utilizado tamb?m o m?todo LTT ?s estruturas ressoadoras retangulares de fenda com m?ltiplas camadas, para a obten??o da freq??ncia de resson?ncia bem como toda a teoria que envolva os par?metros eletromagn?ticos da estrutura em estudo. As an?lises desenvolvidas neste trabalho foram realizadas com utiliza??o do m?todo LTT Linha de Transmiss?o Transversa, no dom?nio da Transformada de Fourier que utiliza uma componente de propaga??o na dire??o y (transversa ? dire??o real de propaga??o z), tratando assim as equa??es gerais dos campos el?tricos e magn?ticos em fun??o de yE e yH . A teoria PBG ser? aplicada para a obten??o da permissividade relativa para as polariza??es s e p dos substratos compostos de material fot?nico. Os resultados s?o obtidos com o software comercial Ansoft HFSS, usado para a an?lise precisa do comportamento eletromagn?tico do dispositivo planar em estudo, por meio do M?todo dos Elementos Finitos (FEM). Resultados num?rico-computacionais s?o apresentados em forma de gr?fico em duas e tr?s dimens?es, para aos par?metros de perda de retorno, frequ?ncia de radia??o, e diagrama de radia??o, efici?ncia de radia??o e densidade superficial de corrente para o dispositivo em estudo, e que tem como substratos, materiais fot?nicos e que fora simulado em uma ferramenta computacional apropriada. . No que diz respeito ao projeto do dispositivo planar em estudo s?o apresentados os resultados medidos e os simulados que apresentam boa concord?ncia com as medi??es efetuadas. Estes resultados consistem principalmente na identifica??o dos modos de resson?ncia e na determina??o das caracter?sticas do dispositivo projetado, como freq??ncia de resson?ncia, perda de retorno e diagrama de radia??o

The fifth-generation (5G) wireless network has received a lot of attention from both academia and industry with many reported efforts. Multiple-input-multiple-output (MIMO) is the most promising wireless access technology for next-generation networks to provide high spectral and energy efficiency. For handheld devices such as smartphones, 2×2 MIMO antennas are currently employed in 4G systems and it is expected to employ a larger number of elements for 5G mobile terminals. Placing multiple antennas in the limited space of a smartphone PCB poses a significant challenge. Therefore, a new design technique using dual-polarized antenna resonators for 8×8 MIMO configuration is proposed for sub 6 GHz 5G applications. The proposed MIMO configuration could improve the channel capacity, diversity function, and multiplexing gain of the smartphone antenna system which makes it suitable for 5G applications. Different types of new and compact diversity MIMO antennas with Patch, Slot, and Planar inverted F antenna (PIFA) resonators are studied for different candidate bands of sub 6 GHz spectrum such as 2.6, 3.6, and 5.8 GHz. Unlike the reported MIMO antennas, the proposed designs provide full radiation coverage and polarization diversity with sufficient gain and efficiency values supporting different sides of the mainboard. Apart from the sub 6 GHz frequencies, 5G devices are also expected to support the higher bands at the centimeter/millimeter-wave spectrums. Compact antennas can be employed at different portions of a smartphone board to form linear phased arrays. Here, we propose new linear phased arrays with compact elements such as Dipole and Quasi Yagi resonators for 5G smartphones. Compared with the recently reported designs, the proposed phased arrays exhibit satisfactory features such as compact size, wide beam steering, broad bandwidth, end-fire radiation, high gain, and efficiency characteristics. The proposed 5G antennas can provide single-band, multi-band, and broad-band characteristics with reduced mutual coupling function. The fundamental characteristics of the 5G antennas are examined using both simulations and measurements and good agreement is observed. Furthermore, due to compact size and better placement of elements, quite good characteristics are observed in the presence of the user and the smartphone components. These advantages make the proposed antennas highly suitable for use in 5G smartphone applications. / European Union Horizon 2020 Research and Innovation Programme under grant agreement H2020-MSCA-ITN-2016 SECRET-722424

The fifth generation (5G) has developed a lot of interest, and there have been many reported initiatives in both industry and academics. Multiple-input-multiple-output (MIMO) is the most promising wireless access technique for next-generation networks in terms of spectral and energy efficiency (MIMO). In 4G systems, 2-Element MIMO antennas are already used, while 5G mobile terminals for smartphone hand-held devices are projected to use a bigger number of elements. The placement of many antennas in the restricted space of a smartphone PCB is one of the most critical challenges. As a result, for sub-6 GHz 5G applications, a new design technique based on dual-polarised antenna resonators for 6-Element, 8-Element MIMO configuration is proposed. The proposed MIMO design could improve the smartphone antenna system's chan-nel capacity, diversity function, and multiplexing gain, making it appropriate for 5G applica-tions. For distinct prospective bands of the sub-6 GHz spectrum, such as 2.6, 3.6, and 5.8 GHz, different types of novel and compact diversity MIMO antennas using Patch, Slot, and Planar inverted F antenna (PIFA) resonators are examined. Unlike previously reported MIMO antennas, the proposed designs provide full radiation coverage and polarisation diversity, as well as adequate gain and efficiency values to support several mainboard sides. Apart from sub-6 GHz frequencies, 5G devices are projected to support the centimetre/milli-metre wave spectrum's higher bands. To create linear phased arrays, small antennas can be placed at various locations on a smartphone board. For 5G smartphones, we propose novel linear phased arrays with tiny parts like Dipole and Quasi-Yagi resonators. In comparison to previously published designs, the suggested phased arrays have desirable qualities such as compact size, wide beam-steering, broad bandwidth, end-fire radiation, high gain, and efficiency. With a reduced mutual coupling function, the suggested 5G antennas can provide single-band, multi-band, and broad-band characteristics. Both models and measurements are used to an-alyse the fundamental features of 5G antennas, and good agreement is found. Furthermore, in the presence of the user and the smartphone components, good features are seen due to the small size and superior arrangement of elements. Because of these benefits, the sug-gested antennas are well-suited for usage in 5G smartphone applications.

Submitted by Sandro Camargo (sandro.camargo@unipampa.edu.br) on 2015-05-09T22:22:57Z No. of bitstreams: 1 126110018.pdf: 3775876 bytes, checksum: 4a58f20709bf7c39682924a84079246d (MD5) / Made available in DSpace on 2015-05-09T22:22:58Z (GMT). No. of bitstreams: 1 126110018.pdf: 3775876 bytes, checksum: 4a58f20709bf7c39682924a84079246d (MD5) Previous issue date: 2014-09-08 / Neste trabalho, são apresentadas diferentes técnicas que possibilitam a obtenção de característica dupla-faixa para antenas de microfita especificamente voltadas para aplicações em estações rádio-base de telefonia móvel celular no Brasil. As faixas de frequência de interesse encontram-se no intervalo de 0,824 GHz a 0,960 GHz para a banda inferior e 1,710 GHz a 2,165 GHz para a banda superior. Além de atender as especificações técnicas de faixa de passagem, devem ser atendidos os requisitos de coeficiente de reflexão, polarização, ganho, largura de feixe de irradiação e impedância de entrada na faixa de interesse. Primeiramente, para obtenção de antenas de microfita com característica multibanda, descreve-se a técnica em que são dispostas fendas nos elementos irradiadores, onde são estudadas três topologias de antenas, explicando-se os princípios de funcionamento e destacando-se as particularidades de cada geometria. As três antenas são analisadas e projetadas com o auxílio do software comercial de simulação eletromagnética Ansoft Designer ® , visando levantar os parâmetros elétricos através de diversos estudos paramétricos em função da variação das dimensões das antenas para compreender melhor o comportamento de cada estrutura simulada. A antena com elemento irradiador em forma de H foi a única que cumpriu os requisitos em termos de faixa de passagem e diagramas de irradiação para operação em sistemas de telefonia móvel celular. No entanto, esta geometria resultou em dimensões físicas consideráveis, pois necessita da utilização de múltiplas camadas dielétricas, acarretando em um protótipo de volume considerável e de elevado custo de produção. Outra técnica estudada foi a sobreposição de elementos irradiadores, porém a mesma não é investigada detalhadamente em função de o custo de produção da antena ser mais elevado em comparação a topologias coplanares. Em seguida, uma técnica com irradiadores em fenda anelar e dupla alimentação é proposta. A antena é projetada considerando-se duas portas independentes, uma para cada banda de operação, formando uma antena de dois acessos altamente isolados. Simulações com o software HFSS TM mostraram que é possível satisfazer as especificações para operação em estações rádio-base de telefonia móvel celular. A grande vantagem desta estrutura é a possibilidade de utilização de apenas um laminado de micro-ondas, o que reduz o custo de produção em comparação a outras topologias. Protótipos foram construídos e caracterizados experimentalmente para validar o projeto realizado no simulador eletromagnético. Constatou-se a presença de discrepâncias entre os resultados simulados e medidos. Após simulações paramétricas, verificou-se que o processo de construção alterou a geometria do protótipo em relação ao modelo de simulação. Após a inclusão das imperfeições do processo construtivo no modelo, foi possível estimar as mudanças necessárias no protótipo. Após os devidos ajustes realizados em bancada, os resultados medidos exibiram boa concordância com a previsão teórica. Por fim, realizou-se um estudo de viabilidade da utilização da antena em fenda anelar dupla-faixa para composição de uma rede de antenas para estações rádio-base. A análise teve como principal objetivo verificar a possibilidade de síntese de diagramas de irradiação em forma de cossecante ao quadrado em ambas as bandas de operação. Excelente resultado foi obtido para a banda inferior, enquanto que algumas limitações foram encontradas na banda superior. / In this work we present different techniques for achieving the dual-band feature for microstrip antennas aimed to be used in the mobile communication base stations of Brazil. The focused frequency range for lower and higher bands is in the 0.824-0.960 GHz and 1.710-2.165 GHz intervals, respectively. In addition to comply with the technical specifications, the solution is also supposed to meet the requirements of return loss, polarization, gain, beamwidth radiation and input impedance in the focused frequency range. Initially, in order to obtain microstrip antennas with dual-band characteristic, we describe the technique in which slots are placed in the irradiating elements. Three antenna topologies are analyzed in its operation principles, emphasizing the particularities of each geometry. The antennas are designed with support of Ansoft Designer ® , a commercial software that simulates electromagnetic features, in order to find out the electrical parameters through parametric studies and to better understand the behavior of each simulated structure. These studies considered the variation in the dimensions of antennas. The H-shaped microstrip antenna was the only one able to fulfill the requirements of bandwidth and irradiation diagrams for operation in mobile communication. However, this geometry originated an antenna of considerable physical dimensions, because it requires the use of multiple dielectric layers, resulting in a prototype of considerable volume and high production cost. Another technique studied was the stacking of irradiating elements. However it isn’t investigated in detail because of the production cost of the antenna, which is higher than the ones of coplanar topologies. After all that, we propose a technique based in annular-slot antennas and double feed. The antenna is designed considering two independent ports, one for each band of operation, making an antenna of two highly insulated accesses. Simulations by the HFSS TM software have shown that it’s possible to comply with the specifications for operation in base stations of the mobile communication. The biggest advantage of this structure over other topologies is that it may be made of only one microwave laminate, reducing the production cost. Prototypes were built and measured to validate the design in the electromagnetic simulator. It was noted the discrepancies between the simulated and measured results. After running parametric simulations, we found out that the building process of the prototype changed the geometry of the simulation model. We included these imperfections in the model and it was possible to estimate the necessary changes in the prototype. After inclusion of the adjustments, the measured results behaved just alike the theoretical prediction. Finally, we’ve done a feasibility study on the use of the dual-band annular slot antenna for making an array of antennas for base stations. The study aimed to verify the suitability of synthetizing squared-cosecant shaped pattern in both operation bands. We got excellent results for the lower band, although some limitations were found for the higher band.

This thesis presents various integrated antenna solutions for different types of systems and applications, e.g. wireless sensors, broadband handsets, advanced base stations, MEMS-based reconfigurable front-ends, automotive anti-collision radars, and large area electronics. For wireless sensor applications, a T-matched dipole is proposed and integrated in an electrically small body-worn sensor node. Measurement techniques are developed to characterize the port impedance and radiation properties. Possibilities and limitations of the planar inverted cone antenna (PICA) for small handsets are studied experimentally. Printed slot-type and folded PICAs are demonstrated for UWB handheld terminals. Both monolithic and hybrid integration are applied for electrically steerable array antennas. Compact phase shifters within a traveling wave array antenna architecture, on single layer substrate, is investigated for the first time. Radio frequency MEMS switches are utilized to improve the performance of reconfigurable antennas at higher frequencies. Using monolithic integration, a 20 GHz switched beam antenna based on MEMS switches is implemented and evaluated. Compared to similar work published previously, complete experimental results are here for the first time reported. Moreover, a hybrid approach is used for a 24 GHz switched beam traveling wave array antenna. A MEMS router is fabricated on silicon substrate for switching two array antennas on a LTCC chip. A concept of nano-wire based substrate integrated waveguides (SIW) is proposed for millimeter-wave applications. Antenna prototypes based on this concept are successfully demonstrated for automotive radar applications. W-band body-worn nonlinear harmonic radar reflectors are proposed as a means to improve automotive radar functionality. Passive, semi-passive and active nonlinear reflectors consisting of array antennas and nonlinear circuitry on flex foils are investigated. A new stretchable RF electronics concept for large area electronics is demonstrated. It incorporates liquid metal into microstructured elastic channels. The prototypes exhibit high stretchability, foldability, and twistability, with maintained electrical properties. / wisenet