Studies on RF-optical dual mode wireless communication modules

Some recent studies on radio-frequency (RF) and free-space optical (FSO) dual-mode communication are reported. A novel hybrid packaging is proposed to integrate RF/FSO front-end circuits on a single compact PCB by sharing space and structural components. Full-wave electromagnetic simulation was applied to design RF and predict coupling between RF and optical circuits. A hybrid RF/FSO package design was developed, prototyped and experimentally studied using a modified quasi-Yagi antenna with split directors to form pads for optical transmitting (VCSEL) and receiving (PiN) diode chips. Dual-mode link connectivity was investigated in simulations and experiments. A data rate of 2.5 Gbps was demonstrated for the optical channel despite 15-20 dB electromagnetic coupling between the optical and microwave circuits.