Modern millimeter-wave technologies [Book Review]

The evolution of practical radio engineering has proceeded from the loog and medium wave transmitters of the 1920s toward the current L-band cellular networks and terrestrial microwave links operating in the Cand Ku-bands and then to satellites. A similar process has been observed in radar starting from the 30 MHz British Chain Home up to the current Long Bow system on-board the AH-64. Strictly speaking, the true history is a bit different as many of us know because millimeter wave experiments were carried out by various scientists in India, Germany, and the US about 100 years ago. However, the lack of suitable and low-cost technological processes prevented real products from appearing in those days. The rush toward higher carrier frequencies and shorter wavelengths is, and has been, explained by the lack of free spectrum in the currently allocated bands of course, in conjunction with the continuously increasing data rates. If we have available 20 kHz at 1 GHz, this will be converted to 2 MHz at 100 GHz when the same proportional ratio of information (or modulation) bandwidth andcenter frequency is maintained. In addition to this, the fundamental properties of millimeter wave devices make them attractive for a number of tasks. If the wavelength is small, the components get smaller (or actually they have to be, otherwise they will not work) and within specific portions of the higher frequency band, the user . may benefit from protective attenuation caused by the atmosphere, whereby small-sized networks become feasible. Two distinguished Japanese scientists, Tasuko Teshirogi and Tsukasa Yoneyama have collected and edited the book under review, Modern MillimeterWave Technologies, which was originally published in 1997 in Japan and has now been translated into English by 10s Press. Besides Teshirogi and Yoneyama, five other leading Japanese research fellows contributed to the publication. The background of the authors is two-fold; four are, or have been, working in the Communications Research Laboratory (CRL), which is an organization under the Japanese government, two are university scientists; and one is a promising university scientist currently working in the US. The book is divided into nine main chapters. After the introduction, Chapter 2 discusses transmission lines and basic tools for analyzing them; Chapter 3 is about passive components; Chapter 4 is about millimeter wave antennas and, 4