A Fully Bidirectional 2.4-GHz Wireless-Over-Fiber System Using Photonic Active Integrated Antennas (PhAIAs)

This paper describes a low-cost scheme for im- plementing 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 vertical- cavity 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 compres- sion point, and spurious-free dynamic range are measured in the links. The fully bidirectional system, which is far from being com- pletely 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. Index Terms—Antennas, photodiodes, radio-over-fiber, VCSELs.