Yes / Two miniature low profile PIFLA antennas with a compact volume size of 30mm × 15mm × 8mm has presented in this paper. By applying the magnetic wall concept a reduced size dual-band and a wideband half PIFLAs for WLAN (2.4GHz/5.2GHz) and UWB applications are achieved. The dual-band antenna shows a relative bandwidth of 12% and 10.2% at ISM2400 and IEEE802.11a frequency bands respectively for input return loss less than 10dB. By carefully tuning the geometry parameters of the dual-band proposed antenna, the two resonant frequencies can be merged to form a wide bandwidth characteristic, to cover 3000MHz to 5400 MHz bandwidth (57%) for a similar input return loss that is fully covering the lower band UWB (3.1-4.8GHz) spectrum. The experimental and simulated return losses on a small finite ground plane of size 30mm × 15mm show good agreement. The computed and measured radiation patterns are shown to fully characterize the performance of the proposed two antennas. / MSCRC

Orientador: Leonardo Lorenzo Bravo Roger / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Tecnologia / Made available in DSpace on 2018-08-26T21:14:03Z (GMT). No. of bitstreams: 1 SantosSouza_GilbertodeTadeu_M.pdf: 4051949 bytes, checksum: 3271a81290629f1d51c661d022a0cbd7 (MD5) Previous issue date: 2015 / Resumo: O projeto e a análise teórico-experimental de uma nova etiqueta sem chip para RFID com comunicação redundante é apresentado. Esta nova etiqueta poderá ser capaz de operar em duas bandas de frequências diferentes para a transmissão da informação binária, aproveitando a utilização em sua concepção de antenas dual-band. A técnica aqui mencionada é clássica, conhecida como diversidade de frequência, mas é utilizada neste trabalho pela primeira vez aplicada em etiquetas chipless de RFID visando aumentar a confiabilidade da comunicação com as leitoras de RFID. Simulações realizadas do novo dispositivo proposto com o software HFSS (High Frequency Structural Simulator) mostraram o seu desempenho adequado. A metodologia do projeto é apresentada passo a passo e os resultados são analisados e discutidos no texto / Abstract: The project and the theoretical-experimental analysis of a new chipless RFID tag with redundant communication is presented. This new tag may be capable to operate in two different frequencies bands for the transmission of binary information, taking advantage of the use in its design of dual-band antennas. The technique mentioned here is classic, known as frequency diversity, but it is used in this work for the first time applied in chipless RFID tags to increase the reliability of the communication with the RFID readers. Simulations of the proposed new device with HFSS (High Frequency Structural Simulator) software showed an adequate performance. The project methodology is presented step by step and the results are analyzed and discussed in the text / Mestrado / Tecnologia e Inovação / Mestre em Tecnologia

A practical method to design dual-band octagonal patch antenna is introduced. The antenna consists of an octagonal patch with a proximity coupling feed designed to radiate at 900 MHz and 1.8 GHz, respectively. The octagonal dual band patch antenna that is designed using the method introduced is then simulated with 3D FEM based electromagnetic simulator. The proposed antenna design can be used to harvest radio frequency (RF) energy from Wi-Fi and widely spread mobile networks. The simulated and analytical results are compared and good agreement is observed.

Dual band (K and Ka) electronically scanning reflectarray with RF MEMS switches is designed, implemented and measured. Unit cell of the reflect array is composed of conductor backed split-ring elements. In order to steer the beam, the phase of the incident circularly polarized wave is controlled by RF MEMS switches that modify the angular orientation of split-rings individually. Reflectarray is designed using unit cell approach with periodic boundary conditions. The antenna is fabricated by using surface micromachining process developed in METU MEMS Center. Radiation patterns of the antenna are measured and compared with the simulations. It has been shown that the reflectarray is capable of beam switching to 35&deg / in Ka band, 24&deg / in K band.

Wideband and dual band stacked microstrip patch antennas are investigated for the new wideband and dual band applications in the area of telecommunications. In this thesis, aperture-coupled stacked patch antennas are used to increase the bandwidth of the microstrip patch antenna. By this technique, antennas with 51% bandwidth at 6.1 GHz and 43% bandwidth at 8 GHz satisfying S11&lt / -15 dB are designed, manufactured and measured. A dual-band aperture coupled stacked microstrip patch antenna operating at 1.8 GHz with 3.8% bandwidth and at 2.4 GHz with 1.6% bandwidth is designed, produced and measured for mobile phone and WLAN applications. In addition, an aperture coupled stacked microstrip patch antenna which operates at PCS frequencies in 1.7-1.95 GHz band is designed. Dual and circularly polarized stacked aperture coupled microstrip patch antennas are also investigated. A triple band dual polarized aperture coupled stacked microstrip patch antenna is designed to operate at 900 MHz, at 1.21 GHZ and at 2.15 GHz. Mutual coupling between aperture coupled stacked microstrip patch antennas are examined and compared with the coupling of aperture coupled microstrip patch antennas