Home  About us  Contact
 

PIN Diodes (pin + diode)

Distribution by Scientific Domains
Engineering53%

Selected Abstracts

A wideband circularly polarized microstrip patch antenna for 5,6-GHz wireless LAN applications

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 4 2005
G. Yang
Abstract A wideband slotted circularly polarized (CP) patch antenna is introduced for 5,6-GHz WLAN applications. A small 14.6 × 14.6 mm square patch on Duroid 5880 substrate can provide a return-loss bandwidth of 11% and an axial-ratio bandwidth of 8% with a single feed. A possible reconfigurable design achievable using PIN diode or MEMS switches capable of left-hand or right-hand circular polarization is also introduced. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 45: 279,285, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20796 [source]

Design of a vacuum-compatible high-precision monochromatic beam-position monitor for use with synchrotron radiation from 5 to 25,keV

JOURNAL OF SYNCHROTRON RADIATION, Issue 2 2000
R. W. Alkire
The Structural Biology Center beamline, 19ID, has been designed to take full advantage of the highly intense undulator radiation and very low source emittance available at the Advanced Photon Source. In order to keep the X-ray beam focused onto the pre-sample slits, a novel position-sensitive PIN diode array has been developed. The array consists of four PIN diodes positioned upstream of a 0.5,µm-thick metal foil placed in the X-ray beam. Using conventional difference-over-the-sum techniques, two-dimensional position information is obtained from the metal foil fluorescence. Because the full X-ray beam passes through the metal foil, the true beam center-of-mass is measured. The device is compact, inexpensive to construct, operates in a vacuum and has a working range of 8,mm × 10,mm that can be expanded with design modifications. Measured position sensitivity is 1,2,µm. Although optimized for use in the 5,25,keV energy range, the upper limit can be extended by changing metals or adjusting foil thickness. [source]

High-field actively detuneable transverse electromagnetic (TEM) coil with low-bias voltage for high-power RF transmission

MAGNETIC RESONANCE IN MEDICINE, Issue 6 2007
Nikolai I. Avdievich
Abstract The design and construction of a 4T (170 MHz) transverse electromagnetic (TEM) actively detuneable quadrature head coil is described. Conventional schemes for active detuning require high negative bias voltages (>300 V) to prevent leakage of RF pulses with amplitudes of 1,2 kW. To extend the power handling capacity and avoid the use of high DC bias voltages, we developed an alternate method of detuning the volume coil. In this method the PIN diodes in the detuning circuits are shorted when the RF volume coil is tuned, and negatively biased with ,12 V when the coil is detuned. To preserve the high QU/QL ratio of the TEM coil, we modified the method of Nabetani and Watkins (Proceedings of the 13th Annual Meeting of ISMRM, Kyoto, Japan, 2004, abstract 1574) by utilizing a high-impedance (,200 ,), lumped-element, quarter-wavelength transformer. A QU of 500 was achieved for the detuneable TEM, such that incorporation of the detuning network had minimal effect (<1 dB) on the performance of the coil in vivo. Magn Reson Med 57:1190,1195, 2007. © 2007 Wiley-Liss, Inc. [source]

A compact dual-element antenna array for adaptive MIMO system

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2009
Xuan Wang
Abstract A novel compact dual-element antenna array is proposed for adaptive MIMO system. By four embedded PIN diodes in the feeding network, the antenna array has three different working states. It can operate as a dual-element antenna array or work as a single antenna while the unselected antenna is terminated to a lumped matched resistor. As a dual-element antenna array, it has a ,10 dB impedance bandwidth of 595 MHz covering UMTS band with mutual coupling lower than ,15 dB in the whole band. The measured radiation patterns show that the radiation property of the selected antenna keeps steady no matter the other antenna is selected or not. The proposed antenna array can achieve antenna selection scheme to adapt to the time-varying channel conditions. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 348,351, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24044 [source]

An N -bit digitally variable ultra-wideband pulse generator for GPR and UWB applications

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 7 2006
Sertac Yilmaz
Abstract This paper presents a low-cost ultra-wideband (UWB) pulse generator that can vary the pulse duration digitally by using a step-recovery diode (SRD), microstrip transmission lines, and PIN diodes. First, a sharp edge is generated by using SRD circuitry. Then a pulse is formed from the sharp edge through the use of transmission lines and the PIN diodes. Based on the number of transmission lines (N), the duration of the pulse can be varied in 2N steps. The UWB pulse generator circuits are implemented on an FR-4 substrate using microstrip-line technology and UWB pulses with durations of 550 to 2400 psec are measured. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1334,1339, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21620 [source]

Microphotonic wideband tapped optical delay line FIR filter noise analysis

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 6 2005
R. D. Jeffery
Abstract MicroPhotonic broadband RF signal processors utilize true-time-delay methods to perform processing functions that cannot be achieved by conventional electronic methods. Using a tapped optical-delay line, a low-cost adaptive wideband FIR filter can be realized. We analyse the sources of noise for such a filter using commercially available VCSEL sources, PIN diodes, and transimpedance amplifiers. The power at each tap can be equal by using a suitably graded coating, or if the reflectivity is constant, there is an optimum reflectivity that maximizes the signal-to-noise ratio for a given number of taps, as we show in this paper. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 45: 476,480, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20857 [source]

A novel approach to extract accurate design parameters of PiN diode

INTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 6 2007
Tarek Ben Salah
Abstract Accurate modelling of PiN diode transient behaviour is necessary to extract design parameters which are not documented in datasheets. To meet this requirement, this paper introduces a novel approach giving the possibility to identify accurate parameters of a given device. The used technique is based only on two stages. First, the design parameters are initialized and optimized. Second, they are refined by minimizing the cost function which depends on the transient switching parameters (IRM, VRM and trr). With a simple and CPU time-saving approach this technique leads to extract design parameters without necessarily knowing the exact technological architecture of the PiN diode. Moreover, in order to validate the proposed approach and the parameter extraction procedure three commercial diodes are tested. A good agreement between experimental and simulation data is obtained. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Comments on Determination of X-ray flux using silicon pin diodes by R. L. Owen et al. (2009).

JOURNAL OF SYNCHROTRON RADIATION, Issue 5 2009

First page of article [source]

Determination of X-ray flux using silicon pin diodes

JOURNAL OF SYNCHROTRON RADIATION, Issue 2 2009
Robin L. Owen
Accurate measurement of photon flux from an X-ray source, a parameter required to calculate the dose absorbed by the sample, is not yet routinely available at macromolecular crystallography beamlines. The development of a model for determining the photon flux incident on pin diodes is described here, and has been tested on the macromolecular crystallography beamlines at both the Swiss Light Source, Villigen, Switzerland, and the Advanced Light Source, Berkeley, USA, at energies between 4 and 18,keV. These experiments have shown that a simple model based on energy deposition in silicon is sufficient for determining the flux incident on high-quality silicon pin diodes. The derivation and validation of this model is presented, and a web-based tool for the use of the macromolecular crystallography and wider synchrotron community is introduced. [source]

Electromagnetic smart screen for tunable transmission applications

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 6 2008
L. Liu
Abstract Electromagnetic smart screen containing conductive strip array loaded with pin diodes was investigated with numerical and experimental approaches. Transmission coefficient was simulated using finite element method with validation by free space measurement. Tunable EM properties are observed between 3 and 8 GHz, which can be useful for antenna applications. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1510,1514, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23400 [source]