Optically remoted probe for sensing of RF in aerospace radars
The improvement of radar reliability may require the detection and monitoring of its handled power. For this purpose, a new sensor concept based on an optically remoted RF probe was investigated. This work presents such a dedicated photonic system. The optical probe allows dual-regime operations: testing both radar transmit and receive operations. This monitoring performs not only “Go - No Go” tests, but could also be used for calibration. The paper reports the preliminary demonstrations. A new optoelectronic transducer was realised and a mock-up of probe was assembled and tested.
Optically-remoted probes for airborne RF sensors
We detail new concepts of optically-remoted probes that can be applied to sense and calibrate RF systems used in airborne domain. The proposed sensors produce minimal perturbation on the probed electromagnetic fields since they are built from non-metallic material (expect for the tiny integrated antenna element). The inherent low sensitivity and cross-talk to electromagnetic waves of fibre-based transmissions allow the introduction of these probes in the vicinity of the radiating antennas. These approaches lead to significant improvements since they will enable the calibration of the full RF system (starting from its radiating elements up to the RF processing unit), while they can operate not only during integration phases but also during operations.
An electroabsorption modulator module for digital and analog applications
This paper presents an electroabsorption modulator (EAM) module for digital and analog (D/A) applications. Optically broad-band operation of the EAM module is studied for such digital application as wavelength division multiplexing (WDM) systems. Utilizing anisotropic electroabsorption of a multiple quantum-well (MQW) EAM, 40- and 100-nm bandwidth operations in 2.5-Gb/s digital signal transmission over 200-km standard fiber are confirmed by the experiments and the simulations, respectively. For analog applications, low distortion and high link gain characteristics of the EAM module are investigated at the wavelength of 1535 nm. High spurious-free dynamic range of 123 dB/spl middot/Hz/sup 4/5/ and high link gains of -10.3 dB with matching circuit and -20.6 dB without matching circuit are obtained using the EAM module.