“…Higher-resolution, higher penetrating power through cloud, dust, fog, etc., requirement of low voltage power supplies and reduced system size, etc., are some important advantages of mm-wave and sub-mm-wave frequencies (Chang, Hellum, Paul, & Weller, 1977;Gray, Kikushima, Morentc, & Wagner, 1969;Midford & Bernick, 1979). The low DC to RF conversion efficiency of the IMPATT devices operating at these frequencies can be improved through the use of impurity bumps in the doping profile of the diode leading to quasi-Read structures such as hi-lo and lo-hi-lo (Mukherjee & Mazumder, 2009).…”