Coherent combining of RF signals in a traveling-wave photodetector array

Author

Goldsmith, Charles L. ; Magel, Gregory A. ; Kanack, Bradley M. ; Baca, Richard J.

Author_Institution

Texas Instrum. Inc., Dallas, TX, USA

Volume

9

Issue

7

fYear

1997

fDate

7/1/1997 12:00:00 AM

Firstpage

988

Lastpage

990

Abstract

Analog fiber-optic links are used in a variety of microwave applications. The RF insertion loss and RF output power available from these links is currently limited by photodetector optical power handling. Using traveling-wave concepts similar to those in distributed amplifiers, we have demonstrated traveling-wave detector arrays (TWDAs) in which photodetectors are embedded within an artificial transmission line. By feeding this network with suitably time-delayed optical signals, this arrangement coherently combines the RF photocurrents from two detectors, yielding a 6-dB improvement in insertion loss and RF output power, while retaining 12 GHz of operating bandwidth.

Keywords

arrays; microwave links; optical fibre communication; optical fibre losses; optical signal detection; p-i-n photodiodes; photodetectors; transmission lines; 12 GHz; InGaAs; InGaAs p-i-n photodiodes; RF insertion loss; RF output power; analog fiber-optic links; artificial transmission line; coherent combining of RF signals; embedded photodetectors; microwave applications; operating bandwidth; photodetector optical power handling; time-delayed optical signals; traveling-wave photodetector array; Detectors; Distributed amplifiers; Insertion loss; Optical losses; Photodetectors; Power amplifiers; Power generation; Radio frequency; Sensor arrays; Stimulated emission;

fLanguage

English

Journal_Title

Photonics Technology Letters, IEEE

Publisher

ieee

ISSN

1041-1135

Type

jour

DOI

10.1109/68.593375

Filename

593375