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)
—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)
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)
Planar antennas are often called upon to bridge the gap between the photonics and microwave fields. Design of such antennas requires a culmination of knowledge acquired from the study of both research areas. This paper will discuss our efforts in the design of novel planar antenna structures for microwave-photonics applications, which stress a high level of… (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.