EMI Reduction for Enhancing Measurement Performance of EM Wave Absorber Using Horn Antennas

This paper discusses the electromagnetic interference (EMI) reduction for measurement performance of electromagnetic (EM) wave absorber using horn antennas. The measurement performs five configurations, namely measurement of cable loss which performs maximum received signal, measurement of dual horn for achieving maximum interference level, and measurement of device under test (DUT) which consists of three scenarios. The scenarios of DUT are utilizing EM wave absorber with the dimensions of $27.84 \mathrm{~cm} \times 27.84$ cm, metal plate with the same dimensions of $27.84 \mathrm{~cm} \times 27.84$ cm, and commercial absorbent material. From the results, the EM wave absorber which was made of split ring resonator (SRR) with thin wire can reduce interference of EM wave at the frequency range of X-band (8 GHz to 12 GHz) with narrow frequency response compared to the one of commercial absorbent material. The decrement of power received by the EM wave absorber as the indicator of interference reduction and measurement performance enhancement can achieve -20.75 dB at the measurement distance of 25 cm compared to the measurements of metal plat.