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.
Design, Fabrication and Characterisation of Normal-Incidence 1.56-µm Multiple-Quantum-Well Asymmetric Fabry-Perot Modulators for Passive Picocells
SUMMARY We have designed and fabricated air-bridged modulators with bandwidths exceeding 10 GHz, the highest yet realised to date for InGaAsP/InGaAsP multiple-quantum-well (MQW) asymmetric Fabry-Perot modulators (AFPMs). Microwave modulation, measurements of intermodulation between the photodetected downlink and modulated uplink signals, and bi-directional broadband data over fibre transmission experiments have been performed to verify the potential of the AFPM as a single electrical/optical transceiver. We also report the first direct integration of this AFPM with a microstrip patch antenna and present results of a preliminary microwave signal transmission experiment over a distance of 1.4 m in free-space at 5.2 GHz
Multiple quantum well asymmetric Fabry-Perot modulators for RF-over-fibre applications
We describe the development of InGaAsP multi-quantum well asymmetric Fabry-Perot modulators (AFPM) and present measurements of devices operating at 3 GHz. Advantages of the AFPM include low drive voltage and loss, high linearity and simple fibre alignment.