Radar Cross Section Reduction Property of High Impedance Surface on a Lossy Dielectric

Abstract

Abstract-A detailed study on the performance of a high impedance surface on lossy dielectric is presented in this paper. It is observed that the structure, which is an array of square loops on a grounded dielectric, behaves as artificial magnetic condutor, narrowband absorber or perfect electric conductor depending on the dielectric loss. An equivalent circuit modelling is used to theoretically explain how this transition is happening. The observed narrowband absorption (bandwidth = 0.08 GHz) of the thin (0.016λ) lossy dielectric is scalable to different operating frequencies by varying the structure parameters. The simulation studies on the effect of structural and dielectric properties on the characteristics of this HIS are also dealt with in this paper. Experimental investigation is in good agreement with simulated result and equivalent circuit modelling.

Improved Performance of Double-T Monopole Antenna for 2.4/5.6 GHZ Dual-Band Wlan Operation Using Artificial Magnetic Conductors

“…A wider AMC in-phase frequency band with better performance and also a reduced AMC substrate height are obtained by the existence of this air gap. Reducing AMC substrate thickness and accordingly decreasing weight and cost are more evident at low frequencies [3][4][5][6][7][8][9][10][11][12][13][14]. The unit cell simulation is performed in frequency domain, and the reflection phase diagram versus frequency is depicted in Fig.…”

“…The gains of this antenna in 2.4 GHz and 5.6 GHz frequencies are equal to 1.985 dB and 3.991 dB, respectively, which are relatively small. Therefore, an AMC structure which is achieved by repeating a unit cell [7][8][9][10][11] is suggested as a solution for increasing gain and accordingly directivity of the antenna. …”

“…Of course all these advantages can be achieved when the AMC structure actually acts as a perfect magnetic conductor meaning that it reflects the vertical incident wave with phase shift in the interval of [−90 • , +90 • ], especially near 0 • [7,8]. The frequency band corresponding to phase shifts in the mentioned interval is defined as the AMC in-phase frequency band [7][8][9].…”