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We report a recent progress for performance of 90GHz electro-optic modulator with patch-antennas in high-power wireless radio irradiation. Optical sidebands to carrier ratio of −40dB can be achieved by wireless radio irradiation power of 33dBm.
We propose a new nondestructive inspection method for fiberglass-reinforced plastic mortar pipes using microwave guided-mode and photonic techniques. This method is based on precise measurement of microwave evanescent fields along the pipe-wall using electro-optic sensors.
We propose new electro-optic modulators using gap-embedded patch antennas with stacked structure. Utilizing stacked structure, the antenna gain, electric field for modulation, and interaction length increase, then modulation efficiency increases 3.65 dB at 60 GHz.
We have proposed pre-equalizing electro-optic modulatorsusing polarization-reversed structures, whichcan compensate fordispersion effect in long haul fiber communication systems.In this paper,new designswith improvedequalizing characteristicsarereported.
We have proposed a new electro-optic signal converter which enables us to convert wireless millimeter-wave signals to lightwave signals. This is based on a LiNbO3 guided-wave optical modulator combined with vertically-stacked planar patch antennas embedded with a narrow (∼5 µm) gap. Utilizing the stacked structure, the antenna gain, antenna area, and electric field for optical modulation are increased,...
We have proposed and developed array-antenna-electrode electro-optic (EO) modulators for 5G mobile communication in densely-user-located environments. In this paper, we present the first demonstration of wireless data transfer in 60 GHz-band using an array-antenna-electrode EO modulator.
We have proposed and developed electro-optic modulators using array-antenna-electrodes for the conversion of millimeter-wave wireless signals to optical signals in radio-overfiber systems. In this report, wireless signal conversion and discrimination in the 60 GHz band are presented.
In Fibre-Wireless (Fi-Wi) links, conversion devices between wireless microwave/ millimetre-wave and lightwave signals are required. In this paper, we propose a wireless millimetre-wave-lightwave signal converter using an electro-optic (EO) modulator with Quasi-Phase-Matching (QPM) array of orthogonal-gap-embedded patch-antennas on a low-k dielectric material. Wireless millimetre-wave signals can be...
An array-antenna-electrode electro-optic modulator has been designed and demonstrated for millimeter-wave wireless frequency bands. By utilizing a thin LiNbO3 crystal film attached on a base glass substrate of low-dielectric constant, a high-performance operation in millimeter-wave bands can be obtained. The design and experimental verification of the proposed device have been reported. We believe...
We have proposed and developed array-antenna-electrode LiNbO3 modulators operating in the millimeter-wave frequency band. In this paper, high-antenna-gain structures for up-links in wireless communication systems are discussed.
We have proposed high-speed pre-equalizing electro-optic modulators, which can compensate for signal distortion caused by fiber dispersion utilizing velocity-mismatched traveling-wave electrode and polarization-reversed structures. Pre-equalization for 40Gb/s QPSK signals using double Mach-Zehnder waveguides is presented.
A nondestructive measurement technique for Fiberglass-Reinforced Plastic Mortar pipes using Electro-Optic (EO) sensors and microwave propagation is proposed. The change in field distributions of microwave propagating along the pipes was verified clearly using EO sensors.
We propose new 100 GHz-band electro-optic modulators using meta-surface structure for RoF systems. Using strong electric fields in the meta-surface structure, effective conversion is expected. A new technique for quasi-phase-matching is also proposed.
60 GHz-band wireless 4-channel SDM signals were discriminated using an array-antenna-electrode electro-optic modulator with multiple channel waveguides and polarization reversal structures. Conversion to an IF-band signal using photonic technology is also discussed with preliminary experiments.
A new nondestructive inspection method for fiberglass-reinforced plastic mortar (FRPM) pipes using microwave and photonic techniques is proposed. We found that FRPM pipes of 250∼1000 mm in diameter and 20 mm in thickness can be a good cylindrical waveguide with single or a few guided modes for 1∼10 GHz microwave and that the microwave transmission along a FRPM pipe is rather affected by defects in...
We have proposed a pre-equalizing electro-optic (EO) modulator for high-speed optical fiber communication systems. The proposed EO modulator can compensate for the signal distortion caused by fiber dispersion utilizing signal convolution characteristics in polarization-reversed EO modulators. The polarization reversal patterns can be designed using the delta-sigma transformation technique. The analyses...
A new millimeter-wave (MMW) signal generation device using a rectangular waveguide and second order nonlinear optical effect is proposed. Using a T-shaped rectangular waveguide with a suspended LiTaO3 crystal, adiabatic MMW signal injection into the waveguide is obtainable through optical difference frequency generation in the crystal. This device is easy for coupling to standard rectangular waveguide...
Millimeter-wave (MMW) and terahertz-wave are expected to support next-generation large-capacity communication systems. In these frequency ranges, radio over fiber (RoF) technology is useful for signal transfer since there is large loss in cables. For RoF systems, it is essential to convert these frequency signals to optical signals. In this paper, we describe a meta-material structure-based wireless...
New array antenna electrode electro-optic (EO) modulators using a thin EO crystal film stacked on a glass substrate and polarization-reversed structures were proposed for 60 GHz space-division-multiplexing (SDM) wireless systems. 4-channel 60 GHz SDM wireless signals were successfully converted to different lightwave signals according to their irradiation angles. The measured SDM channel isolation...
We have proposed electro-optic (EO) modulators using LiNbO3 waveguides and antenna-coupled electrodes stacked on a low-dielectric constant substrate for radio-over-fiber systems. In this paper, a new design using antenna integrated structures is presented to get high modulation efficiency with a small array and a large area of patch antennas.
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