Ultra-compact quad-channel 28-Gbaud linear driver module for InP Mach-Zehnder modulator

In this paper, a small quad-driver module for InP Mach-Zehnder modulators is presented. To decrease the size of the module, we integrated two channels for the driver IC while improving cross-channel isolation. The driver IC requires no external bias tee. A quad-channel package for two driver ICs was also developed. The size of this module is 14 × 8 × 2.8 mm³. The bandwidth of the driver module is 22 GHz with maximum differential gain of 15.6 dB. These characteristics are adequate for operation at the speed of 28 Gbaud. The footprint per channel is 28 mm²/ch, and the value is smaller than that of previous reports. The external-bias-tee-less design is also effective to reduce mounting area.