Microwave Photonics Microwave Photonics Photonics techniques for generation, transmission, processing of microwave signals
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Microwave Photonics
Microwave Photonics Photonics techniques for generation, transmission, processing of microwave signals
Why photonics techniques
Microwave Photonic Link (Radio on Fiber Link)
INPUT µW
SIGNALS
OUTPUT µW
SIGNALS
OPTICAL FIBER
OPTICAL SOURCE
PHOTO - DETECTOR
• Fiber can be better than coaxial cable
• New functionalities
Fiber Coax - Size 0.25 mm 2-6 mm - Weight 0.073 g/m 30~100 g/m - Loss(dB/km) 0.4~0.8 1000~1500 - Time-Bandwidth Product >106 102
Advantage of Fiber over Coaxial Cable
Application: Mobile Communication Networks
Established Cell
RemoteAntenna Unit
Central Station
Example of Fiber Radio system for closed-area shopping mall (Japan)
Tennjinnbashisuji Shopping Mall (Osaka) Base Station
Topology : Star Number of base units: 2, access units: 9 Fiber length: Approx. 2000 m/2 systems
Courtesy of NTT DoCoMo
Optics fiber (DoCoMo)
Fixed telephone lines (NTT)
Apporox. 50m To another arcade
Courtesy of NTT DoCoMo
Tennjinnbashisuji Shopping Mall Base Station
RoF in the Building
• World Trade Center in Japan (very high building)
Topology:Star Number of base units: 2, access units: 15 Fiber length: Approx. 1200 m/2 systems
Antenna
Courtesy of NTT DoCoMo
Radio-on-Fiber for Closed Area Mobile Services
Optical fiber
Shadow of building
In-building
Underground shopping mall
Antenna base
station
Central Office
Satellite communication
To other building
Household Antenna
base station
► High transmission loss of millimeter-wave - Many antenna base stations - Many closed-area (no service area) ► Radio-on-fiber systems
Broadband Wireless Access
CARRIER FREQ.: Millimeter Waves FCC opened 70, 80 and 90GHz bands for commercial uses (2004/10) Millimeter-wave generation and processing are required
Broadband fixed backbone
network
fiber
Military Applications – (1)
Fiber : flexible, small and light, no EMI Communication Network Radar Systems – Phased Array Antennas
Military Applications – (2)
Fiber : flexible, small and light, no EMI Communication and Radar Systems in Planes and Tanks Inter-Connection between Complex Control Systems
Atacama Large Millimeter Array (ALMA)
ALMA : study the structure of the early universe and the evolution of galaxies The array consists of 64 telescopes with 12-meter dish antennas Location : high-altitude (5000 meters), extremely dry mountain site in Chile's Atacama desert for free from distortions caused by atmospheric water
Construction Sight of ALMA
Photonics in ALMA
A Simple Picture for Fiber Radio Link
µwave to baseband
light to µwave
µwave to light
Requirements • Generation of microwave photonic signals • Transmission of microwave photonic signals • Detection of microwave photonic signal
Important Parameters for Fiber Radio System
Digital Optical Communication Transporting Bits. Bit rate Data Recovery
Bit Error Ratio Eye Opening, Q
Sensitivity (for BER=10-9) Jitter Intersymbol Interference Power penalties
Dispersion, Chirp Reflections, Channel Crosstalk Nonlinearities Error-Free Transmission
Fiber Radio System Transporting and Storing Signals Bandwidth Dynamic Range
Spurious Free Dynamic Range Compression Dynamic Range
Signal-to-Noise Ratio Noise Figure Phase Noise Intermodulation Distortion Power Penalties
Dispersion, Chirp Reflections, Channel Crosstalk Nonlinearities
Output Power High-Fidelity Transmission
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