Design and characterization of a 60 GHz band system-on-packaging with an electro-absorption modulator

Abstract

A 60 GHz band system-on-packaging which was composed of an electro-absorption modulator (EAM), a cascaded LNA, a band pass filter was proposed for the first time, and the RF/RoF (radio-over-fiber) link with the SoP module delivered successfully such a high data rate of a 2.34 Gbps. Those performances were achieved by suggesting appropriate solutions to the technical issues for the development of the SoP module. The impedance matching between the EAM and the LNA was necessary to maximize the RF power to be delivered to the EAM. The impedance matching in a single EAM module which was developed for the characterization of the EAM device, was performed with a double stub and the laser trimming. A novel impedance matching with adjusting a termination resistor and a band pass filter (BPF) was proposed for the SoP module since the methods used in the EAM module had the disadvantages like a low yield, time-consuming process. The value of the termination resistance was chosen as a $500\omega$ with HFSS simulation and measured S parameters of the EAM device, and the electrical length of the termination submount was designed to obtain high voltage standing wave ratio (VSWR) at 60 GHz band for the enhanced efficiency of an electrical-to-optical (E/O) conversion. The BPF was designed to play role of a band selection filter in the RF/RoF link. The frequency response of the SoP module exhibited the properties of the BPF and the response level was changed with the EAM bias which meant the impedance matching between the EAM device and the LNA was accomplished well. The noise figure of a single EAM module was calculated 64 dB and measured 67.6 dB with the gain method and its RF gain was measured -56.5 dB. Such a high noise figure was found out to increase the input minimum level of a RoF link which deteriorates the link performance. To reduce the noise figure in the SoP module, the effects of the gain and noise figure of each component of the RoF link were analyzed and from ...