1-2hit |
Tsukasa YONEYAMA Kazuhiko HONJO
In order to highlight a rapid progress attained in the field of millimeter waves in Japan, this paper describes several key topics including transistors, integrated circuits, planar antennas, millimeter wave photonics, and others.
Howard J. THOMAS Nobuaki IMAI Eiichi OGAWA
This paper proposes a novel optical modulator for a millimeter wave (MMW) subcarrier optic link. The modulator enables the bi-phase modulation of MMW subcarriers. It simplifies the optic link by unifying such functions as IF modulation, up-convertion to MMW, and optical modulation, which are separately equipped in a conventional system. A simple model of a Mach-Zehnder external optical modulator (EOM) is used to illustrate how bi-phase modulation of millimeter wave (MMW) subcarriers can be accomplished by switching the EOM bias with a binary data signal. Experimental results are presented to confirm predictions. A wideband communications test system employing the EOM as a bi-phase modulator and utilizing spread spectrum modulation (1.3 µm optical wavelength, 40 GHz subcarrier, 100 MHz chip rate, 10MHz data rate) was developed. Bit error rate (BER) characteristics of an optical link that includes the proposed modulator are presented and compared with ideal performance and simulated predictions. Degradation of the BER characteristics from the simulation was less than 1 dB at a BER of 10-6. A frequency doubling subcarrier bi-phase modulator is also described.