A measurement method for characterizing RFID chip has been proposed that can measure the approximate Read/Write threshold power and impedance of RFID strap with minimum operating procedures; furthermore, the complicated RF facilities are not required. Obtaining the specifications of RFID strap allows designers to estimate maximum read range of designed RFID tag in advance. Therefore, the implemented cost and design cycle times can be reduced substantially. For the verification of the final match condition of assembled RFID tag, a direct measurement technique has been developed, which not only can verify the final impedance match condition of the assembled RFID tags, but can also be used to identify the resistance and reactance mismatch condition between the RFID chip and antenna. The measurement data obtained from the verification method can also be used to estimate the assembly error introduced by different mounting methods. The use of the corrected circuit model of the RFID chip impedance, which includes the assembly error, helps improve the accuracy of the RFID tag design. In the RFID metal tag design, a series of low profile and miniature RFID tags, which is directly attached on metallic objects, has been developed. A series of low cost and easily produced RFID tag antenna structures also has been realized for RFID application on hanging metallic tag, which makes the RFID solution well suited for metallic tag of labeling system that requires integration of RFID technology. The attached RFID metal tag and the metallic RFID hanging tag cover most of the RFID application on steel products in the steel industry.

Astronomy large-scale surveys require instrumentation to minimize the time required to complete observations of large sections of the sky. Optimizing receiver systems has been achieved through reducing the system temperature primarily by advances in low-noise amplifier technology to a point that the internally generated noise is now fast approaching the quantum limit. Instead, reflector-coupled focal plane arrays are now used to increase the field of view (FoV) by employing either multi-element horn feeds or phased array feeds. Widely spaced (2-3 wavelengths diameter) horn feeds inefficiently sample the available focal plane radiation, thus requiring multiple imaging passes. Alternatively, a more efficient method is to use a narrow element (0.5 wavelengths diameter) phased array feed with a beamformer to produce overlapping beams on the sky, fully Nyquist sampling the focal plane with a single pass. The FoV can be further increased with additional phased array feed (PAF) antenna-receiver modules adding to the contiguous fully sampled region. A 5 x 5 K-band (18 - 26 GHz) single polarization modular PAF incorporating an antenna array of planar axially symmetric elements is designed, simulated, manufactured and tested. Each narrow width tapered slot antenna element has an independent receiver chain consisting of a cryogenic packaged monolithic microwave integrated circuit (MMIC) GaAs amplifier and a packaged MMIC down converting mixer. Synthesized beams and beamformer characteristics are presented. The PAF imaging system performance is evaluated by survey speed and compared to the industry standard, the single pixel feed (SPF). Scientifically, K-band is attractive because it contains numerous molecular transitions, in particular the rotation-inversion lines of ammonia. These transitions are excited in dense gas, and can be used to directly measure kinetic temperatures and velocities of protostars throughout the Galaxy. Depending on the line detected, gas of different temperatures can be probed. It is concluded that even with a higher system temperature, a PAF with sufficient number of synthesized beams can outperform a SPF in imaging speed by more than an order of magnitude. / Graduate

No description available.

Yes / This paper presents empirical results of an innovative beam scanning leaky-wave antenna (LWA) which enables scanning over a wide angle from -35o to +34.5o between 57 GHz and 62 GHz, with broadside radiation centered at 60 GHz. The proposed LWA design is based on composite right/left-handed transmission-line (CRLH-TL) concept. The single layer antenna structure includes a matrix of 3×9 square slots that is printed on top of the dielectric substrate; and printed on the bottom ground-plane are Π and Tshaped slots that enhance the impedance bandwidth and radiation properties of the antenna. The proposed antenna structure exhibits metamaterial property. The slot matrix provides beam scanning as a function of frequency. Physical and electrical size of the antenna is 18.7×6×1.6 mm3 and 3.43􀣅􀫙×1.1􀣅􀫙×0.29􀣅􀫙, respectively; where 􀣅􀫙 is free space wavelength at 55 GHz. The antenna has a measured impedance bandwidth of 10 GHz (55 GHz to 65 GHz) or fractional bandwidth of 16.7%. Its optimum gain and efficiency are 7.8 dBi and 84.2% at 62 GHz. / Partially supported by innovation programme under grant agreement H2020-MSCA-ITN-2016 SECRET- 722424 and the financial support from the UK Engineering and Physical Sciences Research Council (EPSRC) under grant EP/E022936/1.

This diploma thesis is focused on design of various antenna structures, based on slot antennas, created in the wider wall of a rectangular-shaped waveguide. As the substrate, it is used a 3D textile material, while its properties are examined. They were designed structures, that operate with linear and circular polarization, and other related structures, that are used for feeding and power division. Structures are designed to operate at central frequency of 8 GHz and its vicinity.

This thesis presents the rectifying antenna potential for infrared and millimeter wave energy conversion. Infrared imaging is one of the emerging technologies that have attracted considerable attention in the next generation of military, medical, and commercial applications. Moreover, with the ever-increasing congestion of the electromagnetic spectrum at RF and microwave frequencies and the establishment of firm civilian and military requirements best met by millimeter wave systems, the interest in the technology has grown and is now firmly established. During this work a 2.5GHz slot antenna, a 2.5GHz Schottky diode detector, a CPW-to-Microstrip transition, a fully integrated Rectenna element, and a 94GHz slot antenna were designed, fabricated, and tested. Results on the performance of the devices show a great deal of correlation between the simulated and measured data. To perform an initial study, the CPW-fed narrow slot antenna is designed at 2.5GHz and implemented on an FR-4 board. This investigation serves as the basis for the development of the Rectenna element at millimeter wave frequencies. In order to increase the bandwidth of the slot antenna, a 2.5GHz CPW-fed wide slot antenna with U-shaped tuning stub is realized, which provides a 60% increase in bandwidth while keeping the same radiation characteristics. In addition, a set of simulations is performed to show how a reflector plate affects the radiating properties of the slot antenna. A 2.5GHz square-law detector is also designed, fabricated, and tested in order to rectify the RF signal delivered by the antenna. The fabricated detector presents a well matched condition at the design frequency with a dynamic range found to be from --17dBm to --50dBm. The low frequency Rectenna element prototype is then integrated within a single FR-4 board. This is accomplished by implementing a compact via-less CPW-to-Microstrip transition. Finally, a 94GHz CPW-fed wide slot antenna is realized on a 10μm high resistivity silicon membrane. This antenna shows a great deal of similarity to the 2.5GHz slot antenna. This low profile antenna presents at least a 10dB return loss over the entire W band frequency window. Simulated antenna efficiencies of up to 99% were achieved assuming a perfect conductor.

The Master’s Thesis deals with the design of slot antenna array based on the substrate integrated waveguide (SIW). Various supply methods are described and the design procedure is approached. The antenna array was designed for Wi-Fi band of 5 GHz in the Ansoft HFSS simulation software. The optimalized parameters are impedance bandwidth (low reflection coefficient at antenna input in the desired frequency band) and the gain (the maximum value). As the result of the work 3 antenna arrays based on the substrate integrated waveguide are designed and fabricated: antenna arrays 2x1, 2x2 and antenna array 2x2 supplemented with housing for outdoor use. The work also contains a comparison of simulated and measured parameters of antennas.

In this work is proposed a HMSIW linearly polarized slot antenna arrays. The first antenna array is composed of four U-shape slots and the second antenna array is composed of four U-shape slots with three patches placed near the magnetic wall of HMSIW. The patches improve radiating parametrs of the proposed antenna array. The proposed antenna arrays are manufactured a measured.

The desire to counter multipath effects and improve communication links between mobile wireless systems in dense environment has led to much research in implementing antenna diversity. Space diversity, utilizing two or more antennas separated several wavelengths from one another, is one of the most popular method to achieve this operation. Meanwhile, polarization diversity, utilizing two orthogonal polarizations, has become more attractive in reducing cost and size of antenna systems. Polarization diversity is achieved using two orthogonal feeds to excite the two orthogonal polarization planes of the antenna. The challenge associated with designing dual polarized antennas is the need to reduce isolation between the feed and cross polarization level while maintaining a high efficiency. While a number of studies are successful in realizing polarization diversity, their antenna structure typically present more complex structures involving multiple layers. This thesis presents a novel method to implement polarization diversity on a miniature antenna using a simple planar structure. The antenna structure uses two crossed slots further miniaturized using a method derived from a recent study on miniaturized spiral slot antenna. At an operating frequency of ~ 1 GHz, the antenna is capable of achieving efficiency greater than 90% with a size as small as 0.08 .? x 0.08? The dual polarization operation is achieved by exciting the magnetic currents of the crossed slots with two orthogonal coplanar waveguide feeds. Simulation results of the proposed antenna yield an isolation > 15 dB with cross polarization levels > 10 dB. Theantenna structure was designed using CST Microwave Studio and the simulations were performed using IE3D simulation software.

Yes / In this paper, we propose an eight-port/four-resonator slot antenna array with a dual-polarized function for multiple-input-multiple-output (MIMO) 5G mobile terminals. The design is composed of four dual-polarized square-ring slot radiators fed by pairs of microstrip-line structures. The radiation elements are designed to operate at 3.6 GHz and are located on the corners of the smartphone PCB. The squarering slot radiators provide good dual-polarization characteristic with similar performances in terms of fundamental radiation characteristics. In order to improve the isolation and also reduce the mutual coupling characteristic between the adjunct microstrip-line feeding ports of the dual-polarized radiators, a pair of circular-ring/open-ended parasitic structures is embedded across each square-ring slot radiator. The −10-dB impedance bandwidth of each antenna-element is 3.4–3.8 GHz. However, for −6-dB impedance bandwidth, this value is 600 MHz (3.3–3.9 GHz). The proposed MIMO antenna offers good S-parameters, high-gain radiation patterns, and sufficient total efficiencies, even though it is arranged on a high-loss FR-4 dielectric. The SAR function and the radiation characteristics of the proposed design in the vicinity of user-hand/userhead are studied. A prototype of the proposed smartphone antenna is fabricated, and good measurements are provided. The antenna provides good features with a potential application for use in the 5G mobile terminals. / This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement H2020-MSCA-ITN-2016 SECRET-722424. / Research Development Fund Publication Prize Award winner, January 2019.