A new quasi-lumped suspended-substrate stripline structure admitting implementation of miniature highly selective narrowband filters is studied. Appreciable improvement of the device selectivity is achieved with supplementary strip conductors introduced between the resonators, which induce attenuation poles near both passband edges. Furthermore, these supplementary conductors reducing the coupling between the resona-tors allow diminishing the inter-resonator spacing and the total size. A four-resonator filter is synthesized using the intelligence optimization method. Experimental results of the manufactured filter are presented.

This paper suggests a new solution for enhancing the immunity against the influence of size variation in ground on a boardintegrated GPS antenna. The original GPS antenna considered has the advantages of a simple design, low cost, and being directly integrated with the associated circuit board. Nevertheless, its performance depends on the ground of the circuit board. Without any special solution, the original antenna can withstand a ground size enlarged up to 122%, with respect to the minimal size required, for meeting the GPS specification. By using the suggested solution, the antenna can allow a ground size enlarged up to 269%. Thus, the improved antenna is more suitable for practical employment. In this investigation, various prototype antennas, with the suggested solution, were created and examined. Both simulated and measured results obtained demonstrate its promising performance stated above.

Electromagnetic wave scattering by many small particles is studied. An integral equation is derived for the self-consistent field E in a medium, obtained by embedding many small particles into a given region D. The derivation of this integral equation uses a lemma about convergence of certain sums. These sums are similar to Riemannian sums for the integral equation for E. Convergence of these sums is essentially equivalent to convergence of a collocation method for solving this integral equation. By choosing the distribution law for embedding the small particles and their physical properties one can create a medium with a desired refraction coefficient. This coefficient can be a tensor. It may have a desired absorption properties.

This paper presents a reconstruction approach which exploits the field detected by a holographic radar in order to localize and geometrically qualify a set of scattering objects. In particular, thanks to the adoption of the Kirchhoff Approximation, the problem is formulated as a linear inverse one wherein the unknown function is the characteristic function accounting for the support (location and geometry) of the target(s). The reconstruction performances of the approach have been investigated through an accurate numerical analysis, and an experimental validation has also been performed with the aim of testing the effectiveness and the practical relevance of the proposed method.

This paper uses the accurate and computationally efficient complex image technique (CIT) to find the electric field and SAR distributions inside a human head illuminated by a finite-length dipole. The human head model used consists of 3 planar layers of lossy dielectrics. The accuracy of the results is verified by comparison with HFSS software. It was found that the CIT requires about 1 minute and 16 MB of RAM, while HFSS requires about 2 hours and 1.5 GB of RAM to find the SAR distribution using a 2.19 GHz Core 2 Due PC. The CIT method can also efficiently solve other types of antennas on other planar head models.

This paper presents the design and results of a compact Ultra-wideband (UWB) monopole antenna with a dual band-notched characteristic. The antenna consists of a semi-elliptical radiator with two meandered slots on it to produce a deep notch at 3.5 GHz (the center of WiMax band) and another notch at 5.25 GHz (the center of the lower WLAN band). The antenna is fabricated and measured, and the measured impedance bandwidth defined by VSWR<2 is 8.5 GHz (2.5--11 GHz), with the dual notched bands of 3.3--3.7 GHz and 5.12--5.37 GHz are obtained. The computer simulation results of the radiation pattern and peak gain of the antenna also agree well with measurements.

In this paper, a novel nine elements array dielectric resonator antenna (DRA) is presented. The DRA was excited by a microstrip feeder with a rectangular aperture coupled slots. The slot positions were determined based on the characteristic of standing wave ratio over a short ended microstrip. The measured gain of the array DRA operating at 5.84 GHz was about 10 dBi having impedance bandwidth of 60 MHz. The proposed DRA exhibits an enhancement of the gain in comparison with a single pellet DRA. The size of the whole antenna structure is about 60 mm × 40 mm and potentially can be used in wireless systems.

It is a current need of research to extensively use the freely available satellite images. The most commonly available satellite images are Moderate Resolution Imaging Spectroradiometer (MODIS) and The Advanced Very High Resolution Radiometer (AVHRR). The problems with these images are their poor spatial resolution that restricts their use in various applications. This restriction may be minimized by application of the fusion techniques where high resolution image will be used to fuse with low resolution images. Another important aspect of fusion of different sensors data as optical and radar images (where both can provide the complimentary information), and the resultant fused image after fusion may give enhanced and useful information that may be beneficial for various application. Therefore, in this paper an attempt has been made to fuse the full polarimetric Phased Arraytype L-band SAR(PALSAR) image with MODIS image and assess the quality of fused image. PALSAR image has a advantage of availability of data in four different channels. These four channels are HH (Transmitted horizontal polarization and received also in horizontal polarization), HV (Transmitted horizontal polarization and received vertical polarization), VH (Transmitted vertical polarization and received horizontal polarization) and VV (Transmitted vertical polarization and received vertical polarization), which provides various landcover information. The curvelet based fusion technique has been applied to MODIS band 1 and 2 and PALSAR HH (HV and VV bands for assessing the effect of fusion in land cover distinction). The three major land covers agriculture, urban and water are considered for evaluation of fusion of these images for the Roorkee area of India. The results are quite encouraging, and in near future it may provide a better platform for maximize the use of MODIS images.

This research uses innovative approaches for characterizing spring probes, a final-test bottleneck applied to microwave packaging. The modeling method depends on conventional microwave on-wafer measurement. This paper compares the novel microwave 3D direct calibration and measurement to observe the issues of spring probe reliability. We makes the key component of a novel approach to 3D calibration and measurement, the double-sided thru calibration element with delay time delivers from 3D EM simulation. The current study compares the modeling method and 3D direct measurement to prove the capability of the latter and presents the reliability about compressing distance of spring probes.

The development of compact antennas plays an important role in the rapidly growing mobile communication market. This paper presents a novel design technique of the quad-band small internal antenna covering GSM-900/DCS-1800/PCS-1900/IMT-2000 bands. The innovative quad-band built-in handset antenna is developed within the limit of a 44×25×4 mm³ volume. The following document describes a new idea of increasing operational bandwidth for the compact planar inverted F antenna (PIFA). The proposed compact antenna introduces the open-end slots in the ground plane almost all under the radiating patch. The size reduction method is attractive for practical antenna implementations. In addition, the end user's hand handling effects on the performances of the proposed antenna are studied.

A 54-66 GHz sub-harmonic monolithic passive mixer using the standard 0.15 μm pHEMT process is demonstrated. The proposed mixer is composed of a hairpin diplexer, an open stub, and a low-pass filter. The mixer also utilizes a pair of anti-parallel diodes to achieve a subharmonic mixing mechanism. The hairpin diplexer formed with two parallel-coupled line band-pass filters is used to improve the isolation between the radio frequency (RF) and local oscillation (LO) ports. The low-pass filter supports an intermediate frequency (IF) ranging from dc to 1 GHz. This proposed configuration leads to a die size of less than 1.5 mm². With a conversion loss of 15.2--18.3 dB, the 2LO-to-RF isolation is found to be better than 27.5 dB. A high LO-to-RF isolation of 23.5--45 dB over 54--66 GHz RF bandwidth, as well as 1 dB compression power of 8 dBm, can be achieved.

A novel complex structure of Printed Dielectric Resonator Monopole Antenna (PDRMA) with multi-bands operation is presented and investigated. In the proposed structure, a printed fork-like stepped monopole antenna is used for exciting two new modified hemi-cylindrical dielectric resonators with a great relative permittivity of 80. A narrow medium substrate with a low permittivity is also applied between two mentioned dielectric resonators and the monopole antenna, to improve the matching, especially at the lower frequencies. By using this novel designed antenna applying two dielectric resonators with very high permittivity, many frequency wide bands for VSWR < 2 are practically measured and supported which are as follows: 1.54--3.25 GHz (GPS, GSM, PCS, UMTS 2000, 2.4 GHz-Bluetooth, WLAN, WiMax), 3.3--3.6 GHz (WiMax), 3.8--4.4 GHz (C-band), 4.8--6.2 GHz (5.2, 5.5 & 5.8 GHz-WLAN & WiMax). Experimental and numerical results are carried out and discussed, showing good agreement.

A bidirectional directly modulated cable passive optical network (PON) based on a reflective semiconductor optical amplifier (RSOA) as a colorless modulator in the optical network unit (ONU) is proposed and demonstrated. Good performances of downstream carrier-to-noise ratio (CNR)/composite second-order (CSO)/composite triple beat (CTB) and upstream bit error rate (BER) were achieved over a 40-km single-mode fiber (SMF) transmission. This proposed directly modulated cable PON is simpler and cost lower than the externally modulated one.

Resonant modes of multi-layer structures which contain the regions of negative epsilon material (such as a metal in the visible range) are analyzed. Existence of two separate classes of resonant modes is demonstrated. One is related to the excitation of the surface mode at the interface of the regions with opposite signs of the dielectric constant and involve energy transport by evanescent modes throughout the whole structure. The second class involves propagating modes (which form the resonant standing wave) in some regions and the evanescent waves in other layers with ε＜0. It is shown that the resonant transmission is related to the existence of quasi-stationary leaky modes having a finite life-time and characterized by large wave amplitude in the trapping region. It is shown that both types of resonances can coexist in multi-layer structures. It is also shown that the interaction of the symmetric and anti-symmetric surface eigen-modes widens the resonant transmission region.

In this article, a time-domain calibration procedure is proposed for pulsed Terahertz Integrated Circuits (TIC) used in on-chip applications, where the conventional calibration methods are not applicable. The proposed post-detection method removes the unwanted linear distortions, such as interfering echoes and frequency dispersion, by using only one single-port measurement. The method employs a wave-transfer model for analysis of the TIC, and the model parameters are obtained by a proposed blind estimation algorithm. A complete implementation of the method is demonstrated for a fabricated TIC, when used in an on-chip sensing application. The features of interest in the measured signal, such as absorption lines, can be masked or weakened by the distortion of the THz signal happening in a TIC. The proposed signal recovery approach improves the detection of those otherwise hidden features, and can significantly enhance the performance of existing TICs. To show the effectiveness of the proposed de-embedding method, numerical results are presented for simulated and measured signals. The method presented in this article is enabling for accurate TIC applications, and can be utilized to optimally design novel TIC structures for specific purposes.

Planar waveguides with an isotropic chiral core, called chirowaveguides, support the propagation of elliptically polarized modes, making them natural candidates for chiral sensing. We investigate the potential of chirowaveguides as optical sensors responding to changes in the circular birefringence of a medium covering the waveguide. Using first order approximations, we derive expressions for the sensitivities to refractive index and to changes in circular birefringence. The chiral sensitivity is proportional to the achiral sensitivity and to the eccentricity of the mode under consideration. Possible combinations of materials and design conditions for chirowaveguide sensors are discussed with reference to these results. The motivation for this study, besides its theoretical and academic importance, comes from potential applications for enantiomeric integrated optical devices.

The aim of this paper is to discuss the effects of the exposure to Extremely Low Frequency ElectroMagnetic Fields (ELF-EMFs) on non- and excitable cells using in vitro cell models, namely neuron-like cell line (PC12), glioblastoma GL15 as glial model and C2C12 myocytes as muscle model, focusing our attention on standardized protocols for ELF-EMFs generation and exposure. A major issue in laboratory -and likely in natura- studies about possible biological effects of ELF waves is the difficulty in providing standard, reproducible environmental conditions. Hence, as part of the work we have developed an exposure system including a probing scanner, able to sample a given volume and to measure the time-varying magnetic field vector. The system allows detection, monitoring and removal of electromagnetic noise sources, as well as means to assess field homogeneity in terms of intensity and polarization.

The paper presents integrated probe for direct coupling to the WR-10 waveguide with the use of metal filled vias on both sides of the microstrip line. Design and optimization of this novel microstrip-to-waveguide transition has been performed using 3-D finite element method based software HFSS (High Frequency Structure Simulator). A back-to-back transition has been fabricated and measured between 75--110 GHz. The measured return loss is higher than 10 dB and the insertion loss for a single microstrip-to-waveguide transition is about 1.15 dB.

A novel of wideband monopole antenna with UTM-Logo shape is proposed to create specific wide band frequencies which can be applied in the cognitive radio. The antenna is designed to be operated between 1.98 to 6.46 GHz frequency bands (106.16%). It has been fabricated on 30×51 mm² FR4 board with thickness of 1.6 mm and the dielectric permittivity and tangent loss of 4.7 and 0.019, respectively. Two slots also been attached on the ground plane for the purpose of increasing the bandwidth of antenna. Simulation and measurement results show good agreement.

This paper investigates the application of frequency-selective surface (FSS) in reflectarray antennas for the purpose of reducing radar cross section (RCS) level. Different from previous reports, the presented band-stop FSS structure is also characterized by the suppression of surface waves, which makes a contribution to better radiation performance. Two 14 x 14 reflectarray antennas backed on the FSS ground and a solid ground are designed and fabricated. Simulated and measured results show that the FSS ground can improve the `in- band' gain by 1.1 dB, decrease the sidelobe level by 6.4 dB, and reduce the `out-of-band' RCS effectively when compared with the antenna with a solid ground plane of the same size.