In this study, a new microstrip patch antenna with wideband radar cross-section (RCS) reduction is presented. The RCS of the proposed antenna was reduced by subtracting the current-direction slots of the patch, with the radiation performance sustained not only for the current-direction subtraction, but also for the no modification in the ground plane. Modified and reference antenna were fabricated and measured. The simulation and measurement results showed that the modified antenna reduced the in-band and out-band RCS simultaneously with no detriment to the radiation performance. In the frequency band from 3.9 to 8.1 GHz, the RCS of the modified antenna was reduced in the whole band compared with the RCS of the reference antenna. The maximum RCS reduction was 7 dB at a frequency of 6.7 GHz.

d a in k 0 /N. Properly speaking, the proposed antenna is able to operate with contrary beams when d a is between k 0 /5 and k 0 /7. Finally, the closest distance is in region III which this region is the conversion of evanescent to propagation waves [12]. Therefore, we can conclude that the separation distance d a is the key factor to determinate its radiation characteristics. CONCLUSIONThe functions of the metasurface can be easily altered between transmission and reflection by simply changing the distance between the anisotropic fractal metasurface and the radiating element. The concept of the proposed antenna provides a unique opportunity to switch the direction of the main beam and to communicate at different operating frequencies. Moreover, the designed antenna presents a very low profile, since the whole antenna system thickness is of 0.17 k 0 at the higher frequency band of operation. The proposed metasurface-based antenna configuration can be potentially adopted in modern smart communication systems.ACKNOWLEDGMENT ABSTRACT: In this article, a simple hexagonal metamaterial is presented. Different from the design method of parameters optimization, the Figure 8 The corresponding dependencies of front-to-back ratio (FBR) as function of the distance k0/N. [Color figure can be viewed at wileyonlinelibrary.com]

This paper proposes a microstrip antenna with reduced in-band and out-of-band radar cross-section (RCS) by subtracting the area of weak scattered current on the ground plane. Fourteen square slots were subtracted from the ground plane, reducing in-band and out-of-band RCS while maintaining radiation performance. Modified and reference antenna surface current distributions were simulated and analyzed in radiating and scattering modes. Two antenna prototypes were fabricated and measured to verify the simulation. The proposed antenna RCS was reduced compared with the reference antenna in the frequency range 1–4.4 GHz, including in-band and out-of-band frequency bands. Maximum in-band and out-of-band RCS reduction was 16.3 dBsm at the working frequency, and 19.3 dBsm at 3.4 GHz, respectively

In this paper, a coplanar waveguide (CPW)-fed dual-band uniplanar tri-polarization reconfigurable antenna based on the PIN diode switch is proposed. The proposed antenna can be reconfigured between the linear polarization (LP) and the circular polarization (CP) mode, including both the right-handed circular polarization and left-handed circular polarization simultaneously within the dual operating bands. The central frequencies of the bands are 2.63 and 4.42 GHz, respectively, and the overlapped operating bandwidth is 17.8 and 3.40%. The proposed reconfigurable antenna is a closed-slot antenna fed by the CPW transmission line and the reconfigurable mechanism is to regulate the T-shaped driven stub through switching the PIN diodes on and off. The scattering parameters, axial ratio, radiation pattern, gain, and the radiation efficiency of the proposed antenna are all investigated in the following. The optimized antenna has been fabricated to experimental test, the simulated and the measured results agree well with each other. The lower frequency band of the proposed antenna covers the 2.40 GHz WLAN specification and the upper band can be used for the 5 G communication (4.40–4.50 GHz); therefore it is suitable to be applied in the mobile wireless communication.

This paper proposes a new radar cross section (RCS) reduced microstrip antenna incorporating 475 square slots on the patch. The proposed antenna achieves wideband RCS reduction with radiation performance sustained. The modified and reference antenna are simulated and analyzed in radiating and scattering mode, respectively. Prototypes of two antennas are fabricated and measured. Compared with the reference antenna, the simulated result shows the modified antenna RCS reduced in the frequency range 1.1–2.6 GHz, which contains the in-band and out-of-band frequency band simultaneously. And the maximum RCS reduction is 7.6dB at the frequency of 1.19GHz. Besides, the modified antenna can achieve the antenna RCS reduction in the case of oblique incidence. The prototypes of two antennas are fabricated and measured, and the accuracy of the simulation is proved by the measured result. Due to its advantages of simplicity, wideband RCS reduced, broad-angle RCS reduced, the method in this paper is suitable for wideband antenna RCS reduction in space-limited environment.