Abstract-This paper describes a low-cost scheme for implementing in-building distributed antenna systems using the photonic-active-integrated-antenna (PhAIA) concept, whereby photonic devices are integrated directly with planar antennas. Deembedded input impedance is measured for an 850-nm verticalcavity surface-emitting laser and photodiode from 0-10 GHz, and the devices are matched directly to the nonradiating edge of a rectangular-microstrip-patch antenna. Link gain, 1-dB compression point, and spurious-free dynamic range are measured in the links. The fully bidirectional system, which is far from being completely optimized, is then tested over a 300-m laboratory-based multimode fiber link and a 220-m in-building dark-fiber link. Results are shown for throughput and signal-to-noise ratio, and this paper shows that such systems can achieve up to 10-m RF range, at reduced throughput, with no RF amplification.
An experimental study on the effect of weather conditions such as solar radiation, humidity, temperature, and rain on the Long Range (LoRa) communication in a tropical region (Malaysia) via a campus environment has been carried out and analyzed. The weather parameters were obtained from an online meteorological weather station (Meteoblue) and the use of a local automatic weather station. A temperature sensor was attached to the LoRa node to measure the onboard temperature. We analyze the diurnal variation and the effects of the weather condition based on the LoRa link in a LoRaWAN setup. A regular pattern of RSSI was observed with stronger RSSI values having a positive correlation with the atmospheric temperature, onboard temperature, and solar radiation during the day but degrades in late evenings. The positive correlation and pattern observed can be attributed to the prevailing metrological conditions and opens room for further research needed for propagation modeling. The RSSI signals and relative humidity, on the other hand, showed no correlation. Furthermore, strong RSSI signals were obtained when the atmospheric temperature was between 30 -40 o C, and the onboard temperature between 40 -50 o C. No significant impact was observed on the RSSI signals when the rainfall rates vary from 12 mm/h to 180 mm/h. The study presents useful information to be considered on the effects of weather conditions in the propagation model and deployment of LoRa for IoT communication.
Abstract-This paper demonstrates that very low cost wirelessover-fibre systems can be implemented without RF amplification by using lossless matching techniques. Single stub matching circuits were designed on low loss substrates and integrated with photodiode chips and results show that the link gain can be theoretically improved by more than 8 dB. A 2-port link gain model is developed using Agilent ADS which allows simple wideband modeling of such systems. Finally the system is tested using a "live" access point both with and without matching and results show that a maximum RF range of 4 m can be obtained at 2 Mbps data rate over 317 m of installed MMF with no RF amplification.Index Terms-Radio-over-fibre, vertical cavity surface emitting lasers (VCSELs), WLAN.
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