International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This student paper was produced as part of the team design competition in the University of Arizona course ECE 485, Radiowaves, and Telemetry. It describes the design of a telemetry support package for interplanetary exploration. Control and processing of telemetric signals between an earth based control station, an exploratory orbiter and probe pods are the focus of this design. Using this design data retrieval is achieved at a highly reliable rate of 1 error in 10^-10 bits. The exploratory orbiter, carrying a payload of probes, is launched and proceeds along its predetermined trajectory. Commands from the earth-based control station is used to send the orbiter to planetary destinations. The craft then establishes a stable non-geosynchronous orbit. Several probe pods are launched towards the planet at predetermined locations. These probe pods collect and send data, as well as system monitoring information to the orbiting craft. The orbiting craft then retrieves the signals generated by all pods and relays that information to an earth-based control station.

In this paper, at the beginning, we focused our studies on the practical planar antenna designs for wireless communication. We also proposed several antenna designs operating at the widely used bands, such as the ISM, GSM, GPS, 3G bands and their combinations. For the antenna designs at these bands, the circularly polarized wide slot antenna and planar monopole antenna with the conducting plate loading for ISM band application, shorted stacked mircostrip antenna for 3G band application, and the low cost high gain 8Í8 stacked patch array for dual ISM band application have been presented. To provide mobile communication and the accurate position of the user as well, the GSM/GPS dual-band antenna suitable for vehicle application is presented. Finally, the GSM/ISM dual-band antenna designed for the personal communication and wireless local area network is also shown. The performance we have achieved in these antenna designs not only satisfy the specific requirements of the system, but also show good antenna pattern, and gain.

A four-sector switchable WiMAX antenna, for indoor use in the 4.9 -5.0 GHz frequency bands, is presented. The prototype antenna is designed to provide a higher gain in a specified sector region. Furthermore, the radiation beam is electronically steerable to provide space diversity in four different sectors. Each sector of this antenna includes an array of two rectangular microstrip patches. The air gap between the bottom substrate of microstrip patches and the ground plane is increased to 3 mm, which can aid in accomplishing a high-gain and wideband design goal. A solid-state microwave switch is used to select one of the four sectors.

Orientador: Hugo Enrique Hernández Figueroa / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-18T02:42:50Z (GMT). No. of bitstreams: 1 Moretti_Angelo_M.pdf: 24209106 bytes, checksum: 508d580f17f75e3268a4804a1f255b60 (MD5) Previous issue date: 2011 / Resumo: A caracterização eletromagnética do tecido brim Santista, através de medições experimentais e cálculos analíticos da constante dielétrica e tangente de perda desse material foi apresentada de forma pioneira. Para esse propósito foi implementado um confiável e rigoroso método de medição que é exposto em detalhes. A possibilidade da utilização do tecido brim Santista como material dielétrico em dispositivos de radio frequência foi demonstrada de forma irrefutável pelo desenvolvimento, projeto e construção de uma antena têxtil utilizando como substrato este material. O adequado desempenho do protótipo da antena é também mostrado / Abstract: The electromagnetic characterization of Santista denim fabric, through experimental measurements and analytical calculations of the dielectric constant and loss tangent of this material was introduced for the first time. For this purpose it was implemented a reliable and accurate measurement method that is exposed in detail. The possibility of the use of Santista denim fabric as dielectric material in radio frequency devices has been irrefutably demonstrated by the development, design and construction of a textile antenna composed of the substrate with Santista denim, whose proper performance is shown here / Mestrado / Telecomunicações e Telemática / Mestre em Engenharia Elétrica

Orientadores: Francisco José Arnold, Leonardo Lorenzo Bravo Roger / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Tecnologia / Made available in DSpace on 2018-08-19T21:46:41Z (GMT). No. of bitstreams: 1 Grilo_Marcus_M.pdf: 4359440 bytes, checksum: 6cae50e622550385b3c928f7055ed0fe (MD5) Previous issue date: 2012 / Resumo: Este trabalho apresenta a análise, o projeto e a construção de uma antena de banda dupla para as faixas de frequências de 915MHz e 2,45GHz, para aplicação em sistemas RFID. A antena é impressa em um substrato de fibra de vidro e possui estrutura dipolar. Os elementos radiadores estão em faces opostas do substrato o que resulta em baixa capacitância do dispositivo. As simulações computacionais, realizadas no programa HFSS, apresentaram boa concordância com os resultados experimentais. Os resultados mostraram importantes vantagens conseguidas com a antena desenvolvida, tais como estrutura simples e independência e facilidade de sintonia. Além disso, os parâmetros característicos (perda de retorno e ganho) de desempenho da antena são bastante satisfatórios. Propostas para trabalhos futuros também são apresentadas / Abstract: This paper presents the analysis, design and construction of a dual band antenna for the frequency bands 915 MHz and 2.45 GHz, for use in RFID systems. The antenna is printed on a substrate of fiberglass and has a dipolar structure. The radiator elements are on opposite faces of the substrate which results in low capacitance of the device. Computer simulations, carried out in the program HFSS, in good agreement with experimental results. The results showed important advantages achieved with the antenna developed, such as simple structure, independence and ease of tuning. Moreover, the characteristic parameters (return loss and gain) antenna performance are quite satisfactory. Proposals for future work are also presented / Mestrado / Tecnologia e Inovação / Mestre em Tecnologia

This thesis deals with microstrip antennas covered by the metamaterials. First, are described planar antennas, their problems and the emergence of surface waves. Surface waves can cause unwanted coupling among particular parts of the structure and can degrade its parameters. The problem can be solved using an electromagnetic band gap structure (EBG). These periodic structures are able to suppress surface waves in different frequency bands. It is shown how the EBG structure in the function superstate improve directivity and antenna gain. Radiation conventional microstrip antenna with metallo-dielectric EBG superstrate and with the purely dielectric double-layer superstrate is described. The both structures are designed and simulated in CST Microwave Studio program. Further is described the antenna radiation with so-called mushroom structure and metallo-dielectric EBG superstate. The structure is again designed and simulated in CST MWS program. Finally, there are two structures with metallo-dielectric superstate implemented and measured.

Yes / An ultra-wideband microstrip antenna design is considered with respect to applications in breast cancer detection. The underlying design concept is based on ground penetrating radar (GPR). Simulated and measured prototype performance show excellent performance in the input impedance and radiation pattern over the target range from 4 GHz to 8 GHz. The 4 GHz to 8GHz frequency band for microwave imaging perform better in comparison with other microwave frequencies. The antenna also shows a reasonable uniform radiation performance in the broadside direction which contributes to the reduction of clutter levels, thus aiding the reconstruction quality of the final image.

In this thesis the development of a high efficiency harmonic re-radiator, consisting of a diode doubler and conjugate-matched receive and transmit antennas, is described. Diode-based frequency multipliers and rectifiers, coupled with antennas, are of interest for quasi-optical applications, for energy-scavenging and for sensing applications. The device studied operates by receiving an interrogating signal at a frequency of 1.3 GHz and re-radiating a signal at 2.6 GHz. The primary goal of this research was to develop a passive, miniature and effective frequency doubler integrated with planar antennas. The system is referred to as a frequency doubling reflectenna, (FDR). Prediction of accurate performance was achieved by employing precise modeling and measurement methods. The FDR can be utilized in data collection applications. The footprint of the FDR is occupied primarily by the receive and transmit antennas. Therefore, a significant portion of the research focused on the development of compact and efficient planar antennas, which would provide for a miniature FDR. A first-generation FDR design was designed, which utilized quarter-wavelength shorted microstrip patch antennas. The choice of antennas provided a small prototype with dimensions equal to 44 mm by 17 mm. In order to further reduce the size of the harmonic re-radiator, meandered planar antennas were investigated and optimized for efficient operation. A second-generation FDR design, which utilized meandered microstrip patch antennas, was produced and a size reduction of 75% was achieved. Both first- and second-generation harmonic re-radiator designs were designed for low input power operation and provided maximum measured conversion efficiencies of approximately 4.5% and 1.8%, with the input to the diode doubler at -14.5 and -17.5 dBm, respectively. Re-configurable microwave devices, which dynamically operate at different frequencies, are often desirable for sensing applications. Therefore, to conclude this research, a tunable FDR was realized using a semiconductor varactor that provided the dynamic capacitance required for the tunability.

Mobile communication has become an essential part of our daily life. We love the flexibility of wireless cell phones and even accept their lower quality of service when compared to wired links. Similarly, we are looking forward to the day that we can continue watching our favorite TV programs while travelling anywhere and everywhere. Mobility, flexibility, and portability are the themes of the next generation communication. Motivated and fascinated by such technology breakthroughs, this effort is geared towards enhancing the quality of wireless services and bringing mobile satellite reception one step closer to the market. Meanwhile, phased array antennas are vital components for RADAR applications where the antenna is required to have certain scan capabilities. One of the main concerns in that perspective is how to avoid the potential of scan blindness in the required scan range. Targeting to achieve wide-band wide-scan angle phased arrays free from any scan blindness our efforts is also geared. Conventionally, the key to lower the profile of the antenna is to use planar structures. In that perspective microstrip patch antennas have drawn the attention of antenna engineers since the 1970s due to their attractive features of being low profile, compact size, light weight, and amenable to low-cost PCB fabrication processes. However, patch elements are basically resonating at a single frequency, typically have <2% bandwidth, which is a major deficit that impedes their usage in relatively wide-band applications. There are various approaches to enhance the patch antennas bandwidth including suspended substrates, multi-stack patches, and metalized cavities backing these patches. Metalized cavity-backed patch structures have been demonstrated to give the best performance, however, they are very expensive to manufacture. In this dissertation, we develop an alternative low-cost bandwidth enhancement topology. The proposed topology is based on substrate-integrated waveguides. The great potential of the proposed structure lies in being amenable to the conventional PCB fabrication. Moreover, substrate-integrated cavity-backed structures facilitate the design of sophisticated arrays that are very expensive to develop using the conventional metalized cavity-backed topology, which includes the common broadside arrays used in fixed-beam applications and the scanned phased arrays used in RADAR applications.

Beam scanning Microstrip (BSMS) antenna is designed to work at center frequency of 10 GHz for using in the scanning applications of 9 GHz to 11 GHz band. The design parameters are defined and by using an Electromagnetic Simulation software program, the parameters are optimized. A Beam Scanning Microstrip Antenna is produced as a prototype and the measurement&rsquo / s results are compared with theoretical results. In conclusion, the values of deviation between theoretical and experimental results are discussed.