This paper describes a millimeter-wave (MMW) transmission system over fiber-optic links applicable for high-speed mobile communications. The system design is presented considering both the MMW radio link and fiber-optic link. To prove the capability of the MMW fiber-optic link, an experimental system has been constructed. The results of in-door transmission experiments showed that this system could be capable of transmitting 118 Mbps digital signals with a BER of less than 10-6. The developed system is easily applicable to a wireless access system which can connect subscribers with a broadband optical fiber network.

RF Variable Gain Amplifiers (RF-VGA) are important components for integrated TV broadcast receivers. Analog and digital controlled RF-VGAs are compared in terms of linearity and an AGC loop architecture suitable for digitally controlled RF-VGA is proposed. Further linearity enhancement applicable for CMOS implementation is also discussed.