Frequency Characteristics of New Ceramic Stem-Based TO Package Using a Coplanar Waveguide Feed-Line for 10-Gb/s Data Transmissions

A ceramic stem-based transistor outline (TO) package, incorporating a coplanar waveguide (CPW) feed-line, has been proposed allowing 10-Gb/s grade data transmissions. Initially, the frequency response of a cylindrical feed-line for a conventional metal-based TO package was analyzed. It was compared to that of the coplanar waveguide feed-line used for a ceramic-based module, such as butterfly packages. For a laser diode (LD) module-based on an LD chip, the measured 3-dB frequency bandwidths were 3.5 and 7.8 GHz for the conventional and proposed packages, respectively. The results validate theoretical results obtained from modeling a small signal equivalent circuit. Based on these results, it has been proposed a new ceramic-based TO package with a CPW feed-line in ceramic material to improve the frequency characteristics of the TO package. The performance of the proposed package was theoretically observed. It was confirmed that it provides wider frequency bandwidth, compared to the conventional one.