Yusuf Nur Wijayanto

Electrooptic Millimeter-Wave–Lightwave Signal Converters Suspended to Gap-Embedded Patch Antennas on Low-

An electrooptic (EO) millimeter-wave (MMW) to lightwave (LW) signal converter suspended to narrow-gap-embedded patch antennas on a low-k dielectric material substrate was proposed for electrical-optical conversion in radio-over-fiber systems. Direct conversion from wireless MMW to LW signals can be obtained using the proposed device with simple and compact structures. The proposed device can be operated with a low MMW loss and no external power supply. By using the low-k dielectric material for the substrate, the antenna size and interaction length become large compared to a device using a high-k EO crystal. As a result, conversion efficiency can be enhanced. Furthermore, effects of the substrate resonant modes can be eliminated since the rather thin EO crystal (<;100 μm) is used. The conversion efficiency of the proposed device can be enhanced about ten times compared to the device fabricated on an EO crystal. Analysis and experimental results of the proposed device in the 60-GHz band are presented in this paper.

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A novel electro-optic (EO) microwave-lightwave converter using a patch antenna embedded with a narrow gap is proposed and experimentally demonstrated. By embedding a narrow gap at the center of the patch antenna and an optical waveguide located under the gap, a wireless microwave signal can be received and converted to an optical signal directly through EO modulation of a lightwave propagating in the optical waveguide. In the experiment, optical sidebands were observed clearly with the irradiation of an 18GHz wireless signal to the fabricated prototype device. This device operates with no external power supply and no additional modulation electrode. Therefore, it can be operated with low microwave distortion.

Dielectric Materials

We propose a new electro-optic microwave-lightwave converter using two orthogonal optical waveguides and patch antennas embedded with two orthogonal gaps. Wireless microwave signals can be received, separated and converted directly to lightwave signals through optical modulation using the proposed device. This device operates with no external power supply and with low microwave distortion. In addition, it enables us to measure the magnitude, phase and polarization of the wireless signal simultaneously. Experimental demonstrations of the device were presented at the operation frequency of 26 GHz. The device can be applied for electromagnetic compatibility test in the radio-over-fiber link.

Novel electro-optic microwave-lightwave converters utilizing a patch antenna embedded with a narrow gap

Electro-optic wireless millimeter-wave-lightwave signal converters using planar Yagi-Uda array antennas coupled to resonant electrodes were proposed. High conversion efficiency is obtainable due to high gain in Yagi-Uda antennas. The designed device at 38GHz is reported.

ELECTRO-OPTIC MICROWAVE-LIGHTWAVE CONVERTERS UTILIZING PATCH ANTENNAS WITH ORTHOGONAL GAPS

We propose an -cut LiNbO3 optical modulator using gap-embedded patch-antennas for wireless-over-fiber systems. The proposed device is composed of an array of narrow-gap-embedded patch-antennas and an optical waveguide located at the center of the gap without a buffer layer. The modulation efficiency of the proposed -cut LiNbO3 optical modulators was enhanced by 6 dB compared to the -cut LiTaO3-based devices.

Electro-optic wireless millimeter-wave-lightwave signal converters using planar Yagi-Uda array antennas coupled to resonant electrodes

An array of patch-antennas with meandering-gaps on an optical modulator is proposed for wireless millimeter-wave beam-steering through high-speed radio-over-fiber systems. Wireless millimeter-wave can be received by the array of patch-antennas and directly modulated to lightwave by the optical modulator. The wireless millimeter-wave can be steered using the meandering-gaps at the patch-antennas by controlling interaction between millimeter-wave and lightwave electric fields in electro-optic modulation. The basic operation and analysis of the proposed device are discussed. In the experiment, 5 × 5 antenna array in 40 GHz millimeter-wave bands was designed and realized for device characterization and demonstration to wireless millimeter-wave beam-steering. There were five variations of wireless millimeter-wave beam-steering for one-dimensional in xz- or yz-planes that can be obtained with wireless millimeter-wave steerable beams of about ±30°. Additionally, 25 variations of wireless beam-steering can be obtained for two dimension in xyz-space through orthogonal optical modulation. The proposed device is promising to be applied in millimeter-wave/tera-hertz bands for future directional wireless communication and sensing with high-speed and high-resolution operation.

X-Cut LiNbO 3 Optical Modulators Using Gap-Embedded Patch-Antennas for Wireless-Over-Fiber Systems

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.

Array of patch-antennas with meandering-gaps on optical modulator for wireless millimeter-wave beam-steering

We propose electro-optic modulators suspended to patch-antennas embedded with a narrow-gap on low-k dielectric materials. The analysis and experimental results of the proposed devices for 60GHz bands are presented with measured modulation efficiency of ~50dB.

Performance of 90GHz electro-optic modulator with patch-antennas in high-power wireless irradiation

We propose a new wireless millimeter-wave (MMW) to lightwave (LW) signal converter using an electro-optic crystal suspended to narrow-gap-embedded patch-antennas on a low-k dielectric substrate. Wireless MMW signals can be received by the patch-antennas and converted to LW signals by use of the MMW electric field across the narrow-gap for electro-optic (EO) modulation. An aperture area of the patch-antennas is about 4 times larger than that fabricated on a high-k EO crystal only as the substrate. The MMW electric field across the narrow-gap of the proposed device also becomes 10-times stronger than that using the high-k dielectric EO substrate. Therefore, the conversion efficiency enhancement of approximately 20 dB can be obtained using the proposed device. It is compact, passive, and operated with extremely low MMW distortion in high-speed radio-over fiber communication and measurement systems.

60GHz electro-optic modulator suspended to patch-antennas embedded with a gap on low-k dielectric material

We proposed a new wireless electromagnetic signal discrimination device using electro-optic modulators and an array of planar patch antennas embedded with orthogonal gaps. Wireless electromagnetic signals can be detected and converted directly to lightwave signals through optical modulation. The magnitude, phase, and polarization of the wireless signal can be measured precisely and identified. By using meandering gap structures, the directivity of the wireless signal conversion can be tuned more precisely. Furthermore, the directivity of the wireless signal conversion in two-dimensional space can also be obtained by comparing two orthogonal modulated lightwave signals from two orthogonal optical waveguides. The design and analysis of the device and experiments at an operational frequency of 26 GHz are presented.