High-performance dual-band Doherty power amplifier and non-uniform circularly polarized antenna array require impedancetransforming unequal dual-band 90◦ branch-line couplers for power dividing and phase shifting in the feed networks. In this paper, an analytical design methodology of generalized impedance-transforming dual-band branch-line couplers for arbitrary coupling levels is proposed. Th...

The Fourier transform of a coherent optical image can be evaluated physically by use of a single lens plus free-space propagation, thereby providing the basis for the field of Fourier optics. I point out that one can similarly evaluate the discrete Fourier transform of a sampled or pixelated optical array physically by passing the discrete array amplitudes through a network of single-mode fiber...

The scattering characteristics of a phased array depends on its feed network. The variation of scattered fields within the feed network affects the antenna mode scattering. In this paper, an attempt is made to determine the radar cross section (RCS) of a planar array with parallel-feed network. The scattered field of the array is obtained by following the path of the signals through the antenna...

In this report we describe an adaptation of the Hough transform for the tracking of particles in the CBM STS detector, together with a possible implementation of the algorithm in hardware using FPGA (field programmable gate array) as a level-1 trigger. A first FPGA based R&D hardware prototype that can be used also for a variety of other application (e.g. Data Combiner and Active Buffer) is als...

Introduction: Efficient optical beam splitters are a key component in photonic integrated circuits (PICs). Multimode interference (MMI) couplers have the advantages of compact size, low loss, stable splitting ratio, large optical bandwidth, and good fabrication tolerances [1, 2]. One of the major applications of MMI couplers is power splitters. To date, high performance in output uniformity is ...

A compact (1.2 mm2) fully integrated mid-IR spectrometer operating in the 3 μm wavelength range is presented. To our knowledge this is the longest wavelength integrated spectrometer operating in the important wavelength window for spectroscopy of organic compounds. The spectrometer is based on a silicon-on-insulator arrayed waveguide grating filter. An array of InAs0.91Sb<...

Optical wireless links can offer a very large bandwidth and can act as a complementary technology to radiofrequency links. Optical components nowadays are however rather bulky. Therefore, we have investigated the potential of silicon photonics to fabricated integrated components for wireless optical communication. This paper presents a two-dimensional phased array antenna consisting of grating ...

Optocouplers offer tremendous advantages in minimizing EMI and noise susceptibility. It is not an exaggeration to say that a healthy sprinkling of opto-isolation has often meant the difference between a “good idea” and working product. Yet, these very useful devices are often overlooked as possible solutions in designs because they are perceived to be “slow”. It is true that there are some limi...

Coherent beam combining of many fiber lasers by the Y-shaped complex resonator method realizes both power scaling and spectral narrowing. The basic characteristics of this Y-shaped coherent array, scalability of power summation, and bandwidth narrowing property are presented. As high as 85% addition efficiency with only a few longitudinal-modes was obtained in an array of eight 10-nm bandwidth ...