Search

Miniaturized transparent metallodielectric resonator antennas are developed and integrated on amorphous silicon solar cells. The horizontal metallic strips attached on the sidewalls of transparent low-profile dielectric resonators are used to manipulate electric near-fields and achieve novel dominant modes that represent miniaturized narrowband, wideband, or multiband antennas with various far-field properties. The radiation properties of each mode can also be adjusted to suit a prospective application by a simple change in position and/or size of the strip. The horizontal strip on the sidewall can be as narrow as one twelfth of the resonator height, and the top wall of the resonator is always kept clear to maximize the solar cell efficiency. A comprehensive comparison including far-field, near-field, and impedance properties of different modes is presented. Several prototypes of the integrated antennas were fabricated and tested. The experimental results are along with the theoretical achievements showing miniaturized antennas with maximum dimension as small as $0.18\lambda $ and multimode operation with realized gain higher than 6 dBi. [ABSTRACT FROM PUBLISHER]

Thick film screen-printing technology is employed to introduce planar dielectric antennas. The micron-size-thick film is made from high-permittivity dielectric paste, which is printed on a low-loss low-permittivity microwave substrate to operate as a magnetic wall boundary. A simplified theoretical model is developed to analyze the antenna structure. The accuracy of this model is evaluated by the results of a commercial three-dimensional (3-D) electromagnetic field solver. The model works well with less than 5% deviation from time-consuming simulations, providing the permittivity contrast between the film and substrate is kept high (e.g., > 30). The impact of dielectric loss of the film in antenna performance is significantly less than that of the substrate, allowing medium-loss films (e.g., \boldsymbol\varepsilon^\prime\prime = 3) results in highly efficient antennas with over 95% radiation efficiency. A prototype was made using screen printing and experimentally characterized at Ku-band. The experimental results confirm the theoretical achievements. The measured -10\;\textdB impedance bandwidth of the printable planar dielectric antenna having dimensions of 0.2 \boldsymbol\lambda0 \times 0.2 \boldsymbol\lambda0 is over 10% with a measured gain ranging from 4.5 to 5.5 dBi. Broadside radiation patterns with cross polarization levels of lower than - 20\;\textdB are achieved. This process is compatible with low-temperature cofired ceramic (LTCC) technology where similar idea can be applied to other passive microwave components. [ABSTRACT FROM PUBLISHER]

A new approach is introduced to show that bulk polymers with metallic plates/strips can be employed to design compact lightweight resonator antennas. A new fundamental mode is excited inside the polymer, based on the special boundary conditions enforced by the metallic plates and strip. By properly adjusting the physical parameters (e.g., the gap between metallic plate and strip), the mode is excited in an appropriate shape and significant miniaturization along with good radiation performance is achieved. An antenna structure is fabricated using acrylic $({{\varepsilon}_{r}} = 3)$ and the measured results are compared with the results of other compact antennas, which can be realized using very high-permittivity materials. Besides over 70% reduction in weight, outstanding antenna features such as 10% impedance bandwidth, 5.7 dBi gain, over 90% efficiency, and dimensions smaller than $\lambda/6$, make the proposed approach more suitable for designing compact lightweight antennas. [ABSTRACT FROM AUTHOR]