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Ultra-wideband Applications (ultra-wideband + application)

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Engineering100%

Selected Abstracts

A symmetric log-periodic balun for ultra-wideband application

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 4 2008
Chu-Yu Chen
Abstract Compared with the conventional log-periodic balun, the design of a symmetric log-periodic balun can provide better performance over the entire designed band. A novel ultra-wideband (UWB) balun with 3,6 GHz passband is demonstrated for UWB applications. The problems of fabrication and measurement of the conventional log-periodic balun operated at higher frequency problems can be further improved. The magnitude and phase difference between two output ports are kept balancing at higher band edge portion. The measured amplitude imbalance is about ±1.1 dB with a corresponding phase difference about ±4°. The bandwidth of the balun is around 70%. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 947,948, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23264 [source]

Double annular-ring dielectric resonator antenna for ultra-wideband application

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2007
Yu-Feng Ruan
Abstract A new dielectric resonator antenna (DRA) is proposed in this article for ultra-wideband (UWB) application. A larger annular-ring DRA is placed concentrically outside a smaller one to form a double annular-ring DRA. The antenna is operating at the end-fire mode. The effects of antenna parameters, such as the radiuses and heights of the dielectric resonators as well as the probe length are investigated. The proposed double annular-ring DRA can offer an impedance bandwidth up to 3,11.2 GHz for a return loss less than ,10 dB. The radiation patterns are stable in the passband. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 362,366, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22140 [source]

Alternative approach to low-noise amplifier design for ultra-wideband applications

INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 2 2007
Qiang Li
Abstract Conventional ultra-wideband low-noise amplifiers require a flat gain over the entire 3.1,10.6 GHz bandwidth, which severely restraints the trade-off spaces in low noise amplifier design. This article proposes a relaxed gain-flatness requirement based on system level investigations. Considering the wireless transceiver front-end with antenna and propagation channel, the unflat-gain low-noise amplifier with an incremental gain characteristic does not degrade the performance of overall system. As an alternative to its flat-gain counterpart, the proposed unflat gain requirement tolerates gain ripple as large as 10 dB, which greatly eases the design challenges to low-noise amplifier for ultra-wideband wireless receivers. Two low-noise amplifier examples are given to demonstrate the feasibility and design flexibility under the proposed gain-flatness requirement. © 2007 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2007. [source]

A low voltage folded cascode LNA for ultra-wideband applications

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 11 2010
Sunil L. Khemchandani
Abstract A low noise amplifier scheme to achieve low-voltage and wide-bandwidth operation is presented. This circuit is based on folded cascode topology combined with wideband impedance matching and shunt peaking load. One of the drawbacks of the proposed scheme is that it uses more area than the conventional cascode due to the two additional inductors and capacitors to implement the capacitively coupled LC tanks. To reduce the area of the circuit, we have used stacked inductors, a brief study of these kinds of inductors is presented. Two low noise amplifiers have been fabricated using a mature 0.35 ,m BiCMOS technology, one using the cascode conventional approach and the other using the proposed topology. Measurement results show that for the same transistors operating conditions, the low-voltage amplifier performance is similar than the conventional cascode. By virtue of the small area of stacked inductors, the size of both low noise amplifiers is comparable. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2495,2500, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25530 [source]

A novel compact CPW-fed planar monopole antenna with modified stair-style ground for ultra-wideband applications

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 9 2010
Y.-B. Yang
Abstract In this article, a simple and compact CPW-fed planar monopole antenna for ultra-wideband applications is presented and investigated. The proposed antenna with a small size of 26 mm × 26 mm × 1 mm is composed of a gourd-like radiation element fed by a CPW feed line, and a modified stair-style ground. The proposed antenna has been successfully designed, fabricated, and measured. The measured results show that the antenna achieves a wide impendence bandwidth from 3.1 to 15.2 GHz with return loss less than ,10 dB. In addition, it exhibits a nearly omnidirectional radiation pattern, stable antenna gain, and good time-domain characteristics across the operation band. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 2100,2104, 2010; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/mop.25378 [source]

A band-notched CPW fed antenna with ring ground for ultra-wideband applications

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 8 2010
Qingxin Guo
Abstract A new CPW-fed antenna with band-notched is proposed for ultra-wideband antenna applications. It consists of a ring strip connecting with two triangle patches as the ground and a rectangular patch connecting with a strip as the radiator and feeding line. A narrow slot is embedded in the radiator to obtain notched-band characteristics within bandwidth of 5,6 GHz. Simulated results gotten by FDTD method are given and compared with the experimental results. Measured results show that the antenna can cover a bandwidth from 2.5 to 10.7 GHz for VSWR < 2 except the notched-band. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1691,1694, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25333 [source]

TEM horn optimized for transient radiation

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 3 2001
Ivor L. Morrow
Abstract Theory and measurements are presented to show that careful shaping of antenna metalization can be used to design TEM horn antennas for ultra-wideband applications involving high-fidelity impulsive electromagnetic fields. The effect on the radiated pulse, spectral bandwidth, and transfer function is discussed. A numerical time-domain formulation is described to compute the impulsive radiated far-field waveform, and some experimental results are included to indicate the usefulness of the technique. The ringing action of the antenna is recognized as the crucial parameter constraining the usefulness of the design. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 161,164, 2001. [source]