Heterogeneous Artificial Magnetic Conductor Integrated Low Frequency Quad Band Microstrip Antenna for Underground Wireless Sensor Network

The challenges adhere to design planar antenna for versatile soil condition in wireless underground communication has grabbed the attention of potential researchers and is the present state-of-the-art research. Specifically, the change in underground soil properties (with time and place) demands the requirement of planar antennas (≤1000MHz) with varied operating frequencies. However, designing such antenna with good radiation profile is undeniably thought-provoking as they suffer from very poor gain (usually negative). In this communication, a completely new concept of heterogeneous AMC with quasi-AMC properties has been exploited to yield 4 frequency bands (≤1000MHz) with good measured gains of 3 dBi, 4.1 dBi, 7.8 dBi, 7.5 dBi at 703 MHz, 835 MHz, 937 MHz and 1008 MHz respectively. Despite having a smaller ground plane (0.4λ ₀ × 0.4λ ₀ ), the proposed antenna exhibits good gain and efficiencies in the range of 66% - 92%. The present investigation aims to design the simple and efficient antenna structure which is judiciously achieved through the thoughtful modulation of AMC ground plane impedance.