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Gao L.,South China University of Technology | Zhang X.Y.,South China University of Technology | Zhang X.Y.,State Key Laboratory of Millimetre Waves | Xue Q.,City University of Hong Kong
Electronics Letters | Year: 2012

Presented is a very compact structure for designing harmonic-suppressed bandpass filters with high selectivity. The proposed filter utilises folded quarter-wavelength resonators to miniaturise the circuit size. A novel feeding structure is used to not only generate transmission zeros near the passband but also suppress the third harmonic. To verify the proposed idea, an experimental filter has been implemented. High skirt selectivity and wide stopband are observed in the measured results. The circuit area of the filter is only 7.9×5.4mm (0.1λ g×0.079λ g), where λ g is the guided wavelength at the operating frequency of 2.4GHz. © 2012 The Institution of Engineering and Technology.


Zhou P.,Nanjing University of Aeronautics and Astronautics | Zhou P.,State Key Laboratory of Millimetre Waves | Tang Z.,Nanjing University of Aeronautics and Astronautics | Tang Z.,State Key Laboratory of Millimetre Waves | And 8 more authors.
Electronics Letters | Year: 2012

An optical up-conversion scheme using an optoelectronic oscillator based on a polarisation modulator is proposed and demonstrated. A baseband signal with a bandwidth as large as 5 or 10GHz is successfully up-converted to a 10 or 20GHz carrier without any replacement of the devices in the scheme. The conversion loss is independent of the wavelength of the laser source. The stability of the operation is also investigated. © 2012 The Institution of Engineering and Technology.


Tang Z.-Z.,Nanjing University of Aeronautics and Astronautics | Tang Z.-Z.,State Key Laboratory of Millimetre Waves | Pan S.-L.,Nanjing University of Aeronautics and Astronautics | Pan S.-L.,State Key Laboratory of Millimetre Waves | And 8 more authors.
Guangzi Xuebao/Acta Photonica Sinica | Year: 2012

Wideband photonic microwave downconversion based on an optoelectronic oscillator (OEO) is proposed and demonstrated for the uncompressed HD video radio-over-fiber (RoF) transmission system. By using the injection locking of the OEO, high-quality RF carrier is extracted from the optical microwave signal. The extracted RF carrier is then fed back to the modulator to perform the downconversion in the optical domain. An experiment is performed. The distribution and downconversion of the signal with a carrier frequency of 10 GHz and a data rate of ≥2 Gb/s is verified. The wireless distance is 0.5 m and the length of optical fiber is 10 km. The distribution of a real-time 1.5-Gb/s uncompressed HD video is also demonstrated in the radio over fiber link. The results show that the system features wide bandwidth and low electromagnetic interference. Meanwhile, thanks to the automaic phase tracking of the OEO, no additional phase-locking operation is needed. The overall system is simple and stable, which provides a presentation and demonstration platform for HD video transmission.

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