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We present an electronically-controlled vanadium dioxide (VO2)-based millimeter-wave phase modulator. The phase modulator consists of a resonant meta-surface fabricated on a thin VO2 film integrated with a voltage-controlled heating electrode layer. By varying the applied voltage to the heating electrodes we control the electromagnetic properties of the VO2 layer and shift the resonance frequency...
The development of new permanent magnet materials is of particularly importance since the high-performance Nd2Fe14B are expensive due to the limited reserves of rare earth Nd, Tb, Dy on the earth. In the past several years, much attention has been attracted to the permanent magnet without rare earth[1], such as Zr2Co11, HfCo7 and Mn-based alloys, and excellent performance has been observed. For example,...
We present high-performance terahertz intensity modulators based on a new class of reconfigurable meta-surfaces that offer extreme diamagnetic switching capability over a broad frequency band. We experimentally demonstrate record high modulation depths (> 70%) and modulation bandwidths (> 1.5 THz) through a fully integrated platform at room temperature.
A broadband terahertz intensity modulator based on MEMS-reconfigurable mesh filters is presented and experimentally demonstrated. Modulator operation is based on reconfiguring the geometry of a multi-layer mesh filter from a capacitive configuration to an inductive configuration, which alters device scattering parameters from a low-pass filter to a high-pass filter, respectively. The geometry of the...
KRISS (Korea Research Institute of Standards and Science) has been operating the standard time and frequency broadcasting station (call sign: HLA) since 1984. The station HLA broadcasts continuous time and frequency signals on 5 MHz carrier frequency and 2 kW transmit power. But the poor reception due to radio interference is decreasing users. Therefore to increase the radio reception, a digital modulation...
In this paper we present an in-home optical network infrastructure based on 1 mm core diameter graded-index plastic optical fibre. A combined transmission of a multi-gigabit baseband data stream, based on discrete multitone modulation, and a radio frequency signal, based on ultra wideband technology, is shown. A detailed experimental study on the performance of the two types of signals in the combined...
In-building networks delivering broadband wired and wireless services can be realized cost-effectively with duplex plastic optical fibre, particularly when sharing ducts of electrical power cabling. Point-to-point architectures are well-suited for residential buildings, and bus or star-bus ones for larger buildings.
By using optical fibre, a single in-building network can offer many broadband services to both wired and wireless terminals. Multi-level modulation and dispersion-robust radio-over-fibre techniques allow the use of cost-effective multimode silica or plastic fibre.
The transmission of 64 QAM radio data signals with a data rate up to 150 Mb/s through long single mode fiber links at different frequencies has been experimentally evaluated. The system under study uses the optical frequency multiplication technique for the generation of carriers in the microwave and millimeter-wave bands. Transmission using frequencies of 18.7 GHz, 19.5 GHz, 19.7 GHz and 29 GHz is...
We present, both numerically and experimentally, the nonlinearity effect of the intensity modulator in RoF transmitters through the comparison between single-carrier QAM and multi-carrier OFDM signals. The acceptable RF power level of the multi-carrier OFDM signal is 2 dB less compared with the single-carrier signal for the same EVM penalty of 1%, indicating the degradation due to inter-modulation...
Advanced optically-emulated x-QAM techniques and the modal dispersion-robust radio-over-fiber OFM technique enable the delivery of high-capacity data via a single multimode (silica or polymer) optical fiber in-building network to wired as well as wireless terminals.
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