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In this paper, a novel structure of a reconfigurable Electromagnetic Band Gap (EBG) layer is presented for direct antenna Amplitude Shift Keying (ASK) digital modulation. Therefore, the modulation process, in this paper, is realized without the need to include conventional parts like filters, mixers or power amplifiers. Beside many advantages, the proposed modulation process offers cost, complexity, and weight reductions to suit many modern applications including 5G systems. The reconfigurable EBG layer has two statuses: ON and OFF. Each status produces a certain level of gain enhancement. Via controlling the reconfigurable EBG statuses, the amplitude of the transmitted wave can be controlled. The results show such a system design can modulate the electromagnetic signals directly by varying the gain from 2 dBi for logic_0 (OFF) to 11 dBi for logic_1 (ON). For this, a mathematical model based on ray tracing analysis is conducted to explain the principle of operation of the proposed EBG layer. The antenna and EBG structures fabrication as a system is realized and tested experimentally. The measurements show good agreements with the proposed mathematical model and CST MWS simulations.

This paper presents an enhancement in radio frequency (RF) harvesting for conventional patch antenna using a metasurface layer (MSL). The key point behind such enhancement is inspired by Friis’ equation which states; increasing the antenna gain leads to an increase in the received power. To achieve this goal, a MSL consists of 5×5-unit cells of a modified Jerusalem cross are proposed. The proposed MSL provides gain enhancement of about 10 dBi while the gain of the patch antenna is about 1 dBi. The proposed MSL is fabricated, compacted to the antenna and experimentally characterized. The empirical results indict an excellent agreement with the numerical results in terms of |S11| and radiation patterns. In addition, a set of RF harvesting measurements are made for patch antenna with and without the MSL. The comparison between measurements shows a significant enhancement in the output voltage when the MSL is involved.