Optically-controlled beam forming technique for 60 GHz-ROF system using dispersion of optical fiber and DFWM

60GHz-Band Photonic-Integrated Array-Antenna and Module for Radio-over-Fiber-Based Beam Forming

“…As explained above, the antenna beam can be remotely controlled by just changing the wavelengths of RoF transmitter at the CS. The wavelength tuning range (∆λ) required for obtaining a relative RF phase shift of π is expressed as [9];…”

“…In order to resolve these problems, antenna beam forming is an attractive solution, because it enables us to ensure the high signal quality against the radiointerference among plural BSs, and therefore, many studies of beam forming technique with RF optical communication links have been reported [4]- [6]. As for the optical transmission technology, radio-over-fiber (RoF) is promising, because it has capabilities of a remote radio frequency (RF) signal feeding through optical fibers from the control site (CS) to antenna sites (ASs), which will contribute to significant simplification of the AS configuration [7]- [9]. In addition, when we consider the recent advance of the photonic integration technologies on the high-speed and high power photodiodes (PDs) and the tunable laser sources (TLSs), the RoF technology has a high possibility of further simplification for the current BS architecture [10]- [12].…”

Effects of chromatic dispersion on RF power feeding to array antennas through fiber

“…Although beam forming based on fiber-optic chromatic dispersion was reported earlier[1] [2], distinct demonstration of the beam forming corresponding to 0 -180 degree phase shift by changing the wavelengths of the light sources has not been done. Figure 2 shows an experimental setup for such demonstration, where two tunable light sources were used as a simple example.…”

“…Microwave photonics may give a solution to realize such array antennas and some studies were attempted in the past [1] [2]. When we consider recent advances in semiconductor tunable lasers [3] [4] and high power photodiodes [5], it is right time to revisit the viability in order to realize light weight and cost effective array antennas which can be used in wide range of applications including pico and femto cells or WiFi access points.…”

2-Dimensional beam steering by 2 × 3 photonic antenna using millimeter-wave Radio over Fiber

“…For the total system cost reduction, it is desired to implement smart antennas that are of small size and simple structure. Owing to the recent advances in photonic devices such as photonic IC-based tunable laser sources (TLSs) and high-speed and/or high-output-power photodiodes (PDs) [1][2][3], radio over fiber (RoF) technique is eligible as a solution of such antenna systems, and several related studies have been reported to date [4,5]. Considering the recent rapid increase in mobile traffic, the RoF technique in the millimeter-wave band would become more important in order to achieve long-reach and high-bit-rate RF transmission for future wireless systems.…”