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We report for the first time a planar quasi-Yagi antenna printed on a single layer of high dielectric constant substrate (Duroid, ε r =10.2) which measures 48 % bandwidth (VSWR<2). The antenna radiates an end-fire beam, with a front-to-back ratio >15 dB and cross polarization level below –12 dB across the entire frequency band. A very low mutual coupling… (More)
A novel microstrip-to-waveguide transition utilizing coplanar strips Yagi-like antenna is presented. The X-band transition demonstrates about 40% bandwidth with return loss better than-12dB. This transition should find wide applications due to its high compatibility with MIC/MMIC technology at very low fabrication cost.
— In this paper, the finite-difference time-domain (FDTD) method is applied to calculate the resonant frequency of dielectric res-onators (DR's) with curved surface. The contour-path integral FDTD (CFDTD) is modified to deal with the curved surface of the dielectric body while the traditional rectangular cells are maintained. Results are compared with… (More)
In this paper, we propose and develop a partially shielded tunable filter structure using a varactor-loaded split-ring resonator. The novel physical topology of the filter is suitable for vertical stacking of filters and enables a compact multilayer tunable filter for applications requiring a very wide tuning range. The capacitance range and ratio needed to… (More)
A novel CPW-to-waveguide transition utilizing a uniplanar quasi-Yagi antenna is presented. The X-band back-to-back transition demonstrates 33% bandwidth with return loss better than-10dB. This transition should find a wide variety of applications due to its high MIC/MMIC compatibility and low cost.
—Millimeter-wave generation by photomixing at 1.55 m in long-wavelength velocity-matched distributed pho-todetector (VMDP) is experimentally demonstrated. The VMDP exhibits a dc responsivity of 0.25 A/W, a breakdown voltage of 7–9 V, and up to 15-mA dc photocurrent without damage. Millimeter-wave output powers of 21 dBm at 75 GHz and 24 dBm at 95 GHz were… (More)
In this paper, we propose a soft-decision-based FEC scheme which is the concatenation of a non-binary LDPC (NB-LDPC) code and hard-decision FEC code having a compatibility with existing OTU-4 frame structure. The proposed concatenated NB-LDPC + RS frame structure is also provided and the entire frame size is 18,368 bytes. The proposed NB-LDPC(2304,2048)… (More)
The objective of this study is to establish a relationship of the skin penetration parameters between the three-dimensional cultured human epidermis LabCyte EPI-MODEL (LabCyte) and hairless mouse (HLM) skin penetration in vitro and to predict the skin penetration and plasma concentration profile in human. The skin penetration experiments through LabCyte and… (More)
In the last few years, remarkable progress has been made in ultrafast, and high-speed, high power photodetectors, as reviewed in [ 1,2]. In terms of applications, the high-speed photodetectors can be divided into four general different categories: (1) high-speed digital communication systems, (2) RF photonic systems, (3) ultrafast optoelectronic sampling,… (More)