Q-Track Corporation (United States)

A wireless channel multiplexing method which makes use of the electric and magnetic field components of an electromagnetic wave as separate information carriers is presented. It is based on the observation that the rates of attenuation for electric and magnetic fields with respect to distance are different for electric and magnetic sources in the near-field region. Capacity enhancement is obtained in free space without any scattering. Measured indoor channels at 1 MHz confirm capacity enhancement of the proposed 2 × 2 MIMO link compared with the reference SISO link.

This paper provides a historical overview of ultrawideband (UWB) antennas. Early radio was narrowband in conception, but UWB in practice due to various technical limitations. Oliver Lodge pioneered UWB antenna engineering in the nineteenth century with his invention of both the biconical and bowtie antennas, and J.C. Bose demonstrated the first horn antennas in 1897. These nineteenth century spark-gap UWB antennas were largely forgotten until the 1930s and 1940s when advances in RF technology made short wavelength compact UWB antennas more practical. For lack of wide-scale implementation, many of these mid-century designs were forgotten in turn. By the closing decades of the twentieth century, UWB antennas were still considered “the main limiting factor of a UWB system.” A third century of development kicked off (more-or-less) with the FCC's authorization of UWB wireless systems in 2002. A host of antenna designers re-discovered or reinvented twentieth century designs and advanced the UWB antenna arts further with innovations like compact planar implementations, UWB patch antennas, embedded UWB antennas, and spectral-filtered or frequency-notched designs. The three centuries of UWB antenna development have been characterized by the failure of successive generations of antenna designers to benefit from the lessons of earlier pioneers.