Copyright © 2008 T. S. Kalkur et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
New
systems working at RF, microwave, and millimeter wave will give rise to new services for medical, security, home,
entertain, and communication industries. Active and Passive Microwave Devices
and Circuits are playing an important role in the design of these systems. This
special issue of Active and Passive components is devoted towards the design,
analysis, and fabrication of Active and Passive components.
In the first paper entitled “Dependence on
frequency of the electromagnetic field distribution inside a cylindrical cavity,” the authors explain the
relevant changes in the electron cyclotron resonance ion source behavior for
small variations of the exciting radiation frequency.
The
second paper in this issue “Printed antenna arrays with side lobe suppression”
investigates approaches and their limitations to minimize side lobes in printed
antenna arrays. It also proposes antenna structures with printed pentagonal dipole
arrays.
The
third paper “Isotropic broad-band E-field probe” discusses the development and characterization of isotropic
broad-band E-field probe which has an isotropic reception from 100 MHz to 18 GHz.
In
satellite communication networks, the noise performance and the required
spectral purity of the low noise band receiver are of the important issues.
The fourth paper “Ka band phase locked loop oscillator
for satellite EHF band receiver” deals with the design and fabrication of Ka band phase locked loop oscillator (PLL DRO) with
a fundamental frequency 19.250 GHz for satellite EHF band receiver.
The fifth paper
“The novel microwave stop-band filter” proposes new band rejection element for
implementing stop band filter. This paper also describes the synthesis,
manufacture and testing of fifth-order Chebyshev filters implemented with this
band rejection element.
The sixth paper “Passive
frequency selective surface array as a diffuser for destroying millimeter wave coherence” proposes
the design,
construction, and testing of grounded frequency selective surfaces (FSS) as a
diffuser for destroying millimeter wave coherence which is used to eliminate
speckle in active millimeter wave imaging. The FSS arrays were designed with finite
integral technique and fabricated by etching technique. The S-parameter was
characterized with a free space MVNA and measurement of radiation patterns was
done with a BWO in motorized setup.
In the seventh paper entitled “A new
fractal-based design of
stacked integrated transformers,” novel fractal stacked transformers
were analyzed using full-wave EM simulations and compared in terms of the
inductance and quality factor. The novel fractal stacked transformers show
improved performance over conventional spiral inductor-based transformers.
A novel layout of leaky-wave antennas based
on tapered design has been proposed and investigated in the eighth paper “High
efficiency and broadband microstrip leaky-wave antenna.” This paper also shows that this structure is
attractive for the design of high performance microstrip leaky-wave antennas
for microwave and millimeter wave applications.
The ninth paper entitled “Material parameter measurements for
microwave antireflection coating development”
is on the material parameter measurements for microwave antireflection
coating development.
Prospects of 4H-SiC double
drift region IMPATT device as a photo-sensitive high-power source at 0.7 terahertz
frequency regime is presented in the tenth paper entitled “Prospects of 4H-SiC double drift IMPATT device as a
photo-sensitive high power source at 0.7 terahertz frequency regime.”
The last paper entitled “Modeling and measurements of novel monolithic
filters” presents novel miniaturized multilayer tunable high Q-filters based on hair
pin resonators including ferroelectric materials and it is suitable for chip and
package integration and narrow band applications.
Acknowledgments
The editors are pleased to submit this special issue to Hindawi Publishing Corporation and hope that this issue accomplishes their goal of highlighting outstanding advances in the active and passive microwave devices and circuits. Thanks are expressed to all the reviewers who have read the abstracts and articles. Their contribution has been most valuable.
T. S. Kalkur
Tibor Berceli
Fahrettin Yakuphanoglu