Seung-kee Yang

Edge gain suppression of a planar-type InGaAs-InP avalanche photodiodes with thin multiplication Layers for 10-gb/s applications

Edge-breakdown free InP-InGaAs avalanche photodiodes (APDs) for 10-Gb/s operation were fabricated. Two-dimensional current profiles were measured to investigate the edge breakdown on double-stepped planar APDs. The edge breakdown prominent at high gain increased with the absorption layer thickness for a fixed multiplication thickness (0.25 /spl mu/m). The edge breakdown was suppressed for 0.4-/spl mu/m absorption layer at the gain of ten. A simple physical model was proposed to predict the results successfully. To suppress the edge breakdown, the multiplication layer thickness should be selected so that the breakdown voltage is minimum at the selected thickness.

High sensitive 10-Gb/s APD optical receivers in low-cost TO-can-type packages

Wide bandwidth (8.2 GHz) and high sensitivity (-27.1 dBm at 10/sup -12/ bit-error rate) 10-Gb/s avalanche breakdown photodiode receivers were developed in a transistor outlook (TO)-Can package, for the first time. Low-cost and small-size electrical waveguides using Teflon substrates were designed to transfer radio-frequency signals from the outputs of a transimpedance amplifier to the pins of the package without signal degradations. The signals were further guided to the output pins in the package, which were coaxial transmission lines. Only 0.25-dB insertion loss and -18.8-dB reflection were measured up to 10 GHz in the output lines inside of the package.

Reducing effects of hand phantom on mobile antennas using magneto-dielectric material

In this paper, a practical application of the magneto-dielectric (MD) materials to the mobile handset antennas is presented. The polymer MD composites with the property of low magnetic loss (tan δm <; 0.1) up to 2 GHz are developed using hexagonal ferrites and polymer matrices. The MD composites are applied to manufacture an actual antenna substrate for a mobile handset. Experimental results show that the MD composite antenna is advantageous for an antenna miniaturization and deterioration of performance by a hand phantom.

A reflecting mirror facet (RMF) photodiode suitable for surface-mountable optical package

The Reflecting mirror facet (RMF) photodiodes with two V-grooves and a conventional back-illuminated vertical absorption structure were made for surface mounting and edge illumination applications. The two adjacent V-grooves convert a horizontal beam to nearly a vertical beam. Even with the edge-illuminated structure, RMFPDs showed the high reliability from the buried p-n junction.