System-on-packaging with electro-absorption modulator for 60 GHz band radio-over-fiber link

We developed a system-on-packaging (SoP) with an electro-absorption modulator (EAM) for a 60 GHz band radio-over-fiber (RoF) link. It consists of an EAM device, a microstrip filter, and a low noise amplifier (LNA). The microstrip filter was used to achieve the impedance matching between the EAM device and the LNA and to reject the local oscillator (LO) frequency of the heterodyne system. The frequency response and the effect of the EAM bias voltage of a simple RF/optical link were measured. A 60 GHz band RoF link with 2.4 GHz intermediate frequency (IF) was prepared to measure the transmission characteristics of 16 QAM data.

Introduction

Radio-over-Fiber (RoF) link technology employs optical carriers that are intensity modulated by the microwave signals through optical modulators and transmitted or distributed to an optical receiver via optical fibers. [1], [2] It takes advantages of excellent characteristics of the single mode fiber such as low optical attenuation, wide data bandwidth, and no electromagnetic interference (EMI). The 60 GHz band is considered to use for broadband wireless data transport of up to 2 Gbps in WP AN application because of its spectrum availability, compact size of RF devices, and severe atmosphere attenuation which provides a pico-cell environment. [3] – [5] Carrying a 60 GHz band in a RoF link for a broadband wireless access network takes advantage both of the single mode fiber and the frequency characteristics of the 60 GHz frequency. This link system would be a good candidate of future wide bandwidth wireless access system in the generation wireless communications, telematics, and home networks. [2]