Foreword, Nov. 1976

For more than a quarter of a century, engineers and scientists have been challenging the frontier of microwave technology with the prospect of extending it into millimeter-wave systems applications. The progress toward this goal had been relatively slow. In recent years, however, a significantly increased effort has been directed toward the development of various solid-state devices for use at millimeter-wave frequencies. This has brought a rapid progress in the field of millimeter waves in many countries, particularly in Europe, Japan, and North America.