The Next Wireless Wave is a Millimeter Wave

The past few years has witnessed the emergence of CMOS-based circuits operating at millimeter-wave frequencies. Integrated on a low cost organic packaging, this is the promise for high volume fabrication, lowering the cost and opening huge commercial impact opportunities. As standardization efforts catalyze the interest and investment of the industry, one can count on the spreading of millimeter-wave technology in the consumer electronic market place in the near future. In the past few years, the interest in the millimeter-wave spectrum at 30 to 300 GHz has drastically increased. The emergence of low cost high performance CMOS technology and low loss, low cost organic packaging material has opened a new perspective for system designers and service providers because it enables the development of millimeter-wave radio at the same cost structure of radios operating in the gigahertz range or less. In combination with available ultra-wide bandwidths, this makes the millimeter-wave spectrum more attractive than ever before for supporting a new class of systems and applications ranging from ultra-high speed data transmission, video distribution, portable radar, sensing, de tection and imaging of all kinds. While at a lower frequency the signal can propagate easily for dozens of kilometers, penetrate through construction materials or benefit from advantageous reflection and refraction properties, one must consider carefully the characteristics (in particular strong attenuation and weak diffraction) of the millimeter-wave propagation, and exploit them advantageously. The free-space loss (FSL) (after converting to units of frequency and putting them in decibel form) between two isotropic antennas can be expressed as 1