Abstract-A broadband Perfect Metamaterial Absorber (PMA) on FR-4 Epoxy substrate for X-band and Ku-Band applications is proposed. The unit cell structure is composed of rectangular patches of appropriate shapes and orientation on top of the metal-backed dielectric substrate having a thickness of 2.7 mm (0.16λ L ). The relative absorption bandwidth is 79% (more than 85% absorption) covering the entire X-band and the Ku-Band of the microwave frequencies. The surface current distributions of the top and bottom planes have been analyzed to elaborate the absorption mechanism of the structure. The broadband characteristics of the design support its claim of being useful to a wide range of applications in both commercial and research sectors. Such applications include military and stealth devices, thermal sensors and electronic-cloaking devices.

This paper presents a miniaturized Wilkinson power divider (WPD) with higher order harmonics suppression. The proposed power divider is designed for global system for mobile communication (GSM) application. The quarter wavelength lines of the conventional WPD are replaced by a stub loaded transmission line in order to miniaturize the circuit size. A solution, operating at 1.8 GHz center frequency, has shown that the 2nd and 3rd order harmonics are well suppressed by a level < −15 dB. Further, two differently shaped defected ground structures (DGS) are embedded with the design to suppress the higher order harmonics. Therefore, overall 31% size reduction is achieved, and higher order harmonics are suppressed up to the 9th order (16 GHz) by a level < −15 dB compared to reference WPD. The return loss and isolation performance of the proposed WPD are < −15 dB and < −20 dB, respectively.

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This paper presents a compact Wilkinson power divider (WPD) operating at 0.7 GHz (LTE band) with higher order harmonics suppression based on step impedance shunt stubs (SISSs) and defected ground structure (DGS). The quarter wavelength lines of conventional WPD are replaced by a host line loaded with a DGS and a pair of SISSs. The DGS and SISS of the proposed line serve as a high series inductance and shunt capacitance, respectively. Therefore, a compact quarter wavelength line is designed compared to conventional one. A prototype of the proposed power divider is designed based on the proposed line, which provides a size reduction of 71% as compared to conventional WPD (CWPD) at 0.7 GHz. In addition, upper edge selectivity is found to be 40 dB/GHz along with higher order harmonics suppression up to the 10th order (7 GHz) by a level better than 20 dB. The proposed power divider is experimentally verified with the simulated one and found to be same.

In this work, a dual-band microwave absorber is proposed with a periodic array of unit cells which has dual-split ring geometry on the top of a metal-backed dielectric substrate. The dual-split ring resonator on the top plane is electrically excited by the co-polarized component of incident EM wave and gives two absorption peaks at Wi-MAX (3.5 GHz) and WLAN (5.8 GHz) band due to two resonance modes. These two-resonance modes are named as mode 1 and mode 2 for low and high frequency peaks, respectively. The surface current distributions on the top and bottom planes are studied to gain insight into dual-mode resonance for dual-band absorption of the structure. Some parametric studies are also performed on key design parameters, i.e., split gap, stub length, and split angle for further analysis of the design. The measured results are verified with the simulated ones to test their performance and found to be similar.