The development of compact, power-efficient, multi-band, and reconfigurable antennas over the frequency range of UHF through lower microwave band is of great practical importance for a wide range of applications. With the recent advances in communication and sensor technologies and ever increasing demand for reliable and high data rate communication, the need for novel compact antennas suited for the specific applications is growing in proportion. In general low power capability and compactness are two highly desirable features of all mobile wireless systems. Antennas and RF front-ends are important components of any wireless system and as such must comply with the high efficiency and compactness requirements. Antenna miniaturization does not seem be an important issue at frequencies above 3 GHz. At these high frequencies the free-space wavelength is small and therefore highly efficient antennas with small size can readily be designed. However, considering the wave propagation issues for situations where line-of-sight communication is an unlikely event, such as in an urban environment or over irregular terrain, the use of carrier frequencies above 3 GHz will result in exorbitant path-losses. In these situations the EM spectrum from VHF through S-band are commonly used where there is considerable penetration through vegetation and buildings, wave diffraction around obstacles, and wave propagation over curved surfaces. However, at this frequency range the size of efficient antennas become relatively large and therefore they cannot easily fit on a small mobile transceiver.
Many different approaches for antenna miniaturization based on novel topologies and materials (metamaterials) are being pursued at the Radiation Laboratory.
The ceramic stereo-lithography micro-fabrication method is used to build a highly efficient ceramic Luneburg lens (Gutman’s solution) at Ka-band. IEEE Trans. AP, pp. 790-797, vol. 55, no. 3, 2007.
Wideband, miniaturized Magneto-dielectric resonator antenna with circular polarization. IEEE Trans. AP, vol. 53, no. 11, pp. 3436 – 3442, 2005.
Highly miniaturized (0.03\lambda x 0.03\lambda) on-chip slot planar antenna with high efficiency.
Wideband, transparent, unidirection antenna embedded in armored window.