The manuscript presents a log-periodic microstrip antenna with a defective ground structure (LPMADGS). The antenna is simulated, designed, and validated for C-band applications. The design of the antenna consists of three layers with upper most layer consisting of log-periodic, copper patches with a thickness of 0.035 mm; the middle layer is a 2 mm thick dielectric layer of FR-4 substrate; and the bottom layer is a defected ground structure (concentric ring resonators of 0.035 mm thickness). The suggested antenna design is simulated with a complete ground plane, without ground plane, and with a defective ground plane. The proposed antenna with optimized design is fabricated by wet etched method. The simulated results are approximately similar to the experimentally measured results. The experimentally measured results show transmission peaks at 7.65 GHz and 7.90 GHz. The resonating effect of log-periodic patches with a defected ground structure results in wide-band of 0.91 GHz (−10 dB bandwidth). The proposed antenna structure exhibits a wide bandwidth transmission which mostly resonates in frequency range that lies in C-band. It has future applications for mobile as well as wireless communication.

Abstract A new design of an ultra wide-band metamaterial absorber (MMA), with appreciable high absorptance insensitive to angle of incidence and polarization angle is presented in the manuscript. The MMA structure consists of three concentric rings with non-linear variation in the spacing and the thickness of the rings is controlled by a single parameter. The idea of utilizing nonlinear variation based unit cell resulted in high absorptance ultra wide-band frequency spectrum in X -band. The proposed MMA design is three layered structure. The metamaterial nature of the proposed device is explained by simulated values of Z eff( f ), μ eff( f ), ε eff( f ), and η eff( f ). The FWHM bandwidth of proposed MMA is 6.32 GHz (7.36 GHz-13.68 GHz). The fabricated MMA is ultra-thin with thickness of λo/15.3 at centre frequency 9.8 GHz. The experimental results show absorptance greater than 99% at 7.9 GHz and 11.7 GHz, covering entire X -band range makes this MMA appropriate for providing stealth technology for defense equipments by reducing radar cross section (RCS).

It has been discussed that successful treatment of breast cancer is only possible if there could be early detection of breast lesions.

The usage of internationally acclaimed mammographic databases is important in order to ensure validations and comparison of response from various studies.

Image enhancement refers to an improvement in the visual information content of an image from the point of view of human perception as well as computer vision applications. The primary objective of image enhancement is to modify the visual features (attributes) of an image in such a manner so that it can be made more appropriate for a specific task or an observer.

Non-linear polynomial filtering (NPF) framework has been explored previously as a robust approach for contrast improvement of mammographic images. However, NPF ‘Prototypes: α and β′ have been performance limited; as the contrast improvement has been accompanied with a severe background suppression in mammograms. This affected the visualization of other anatomical structures and diagnostic features in the vicinity of the ROI; these features equally contribute towards diagnostic decision making by radiologists. On the other hand, it is equally difficult to improve the edge strength and sharpness of the ROI without compromising the background content.

A new design of wide-band, co-planar waveguide (CPW) fed, rectangular patch antenna loaded with continuous ring resonators (RPACRR) is proposed for C-band. The proposed RPACRR design consisted top layer of optimized rectangular patches of copper with 0.035 mm thickness, middle layer of FR-4 substrate of thickness 2 mm and the bottom layer of concentric continuous ring resonators (CCRRs) of 0.035 mm. The proposed RPACRR design with dimensions 33.30 mm × 20.22 mm × 2 mm is simulated in two different configurations, with CCRRs and without CCRRs. The simulated results for RPACRR design showed transmission peaks at 3.9 GHz and 5.4 GHz with reflection coefficients of -15.42 dB and -23.01 dB simultaneously. The uniqueness in the design is CPW line, consisting of rectangular patches and replacement of ground patch layer with patches of CCRRs that act as defective ground layer. The combined resonance effect of patch antenna backed by CCRRs resulted in broad-band of 3.53 GHz. The proposed RPACRR design exhibited broad-band transmission band-width that resonates at frequencies lying in C-band with potential application in wireless communication.

The performance of the mammogram enhancement approaches is objectively evaluated as well as benchmarked using various objective IQA metrics to quantify contrast enhancement, edge enhancement and signal-to-noise ratios (Hwang and Peli ).

American College of Radiology (ACR) recommends that annual mammography screening is necessary to be performed for women population above the age of 40.

Consultant radiologists are generally the prime experts for mammogram reading and interpretation.

Last few decades have marked growing interest towards developments in signal processing techniques on account of the diverse spread in multimedia applications (which includes image and video processing).

Non-linear enhancement techniques encompass various categories of approaches. Those specific to or commonly applied for processing of medical images include morphological filtering, fuzzy-based enhancement and non-linear filters.

Image quality is defined as a characteristic of an image that estimates the magnitude of degradation or improvement in its perceived visual characteristics, generally when compared to a reference image.

Breast cancer may be predicted via variety of appearances on mammograms: from the obvious benign or malignant masses, to density variations, subtle asymmetries, to rarely visible and obscured calcifications.

Breast cancer is one of the common globally detected cancers, affecting each year an average of 1.4 million women. It has caused a toll of 1 in 8 out of all cancer-related deaths especially among women under the age of 50. It scores to be the second leading cause of deaths in country as well as other parts of the world (lungs and skin cancer being the major cause of mortality).

Region-based enhancement algorithms operate adaptively based on the availability of features and enhances them with respect to their background (irrespective of its shape or size). Region-based approach defines an adaptive region for processing (about a pixel); whose size is dependent upon the availability of features within that region (Pratt et al. in Image enhancement. PIKS Scientific Inside, pp. 247–305, ). In such a case, contrast manipulation algorithms can be then applied on a region rather than pixel basis.