KARAKTERISASI EKSPERIMENTAL TERMINATOR RF BERBASIS ABSORBER SEKAM PADI BAKAR PADA RENTANG FREKUENSI 2–7,5 GHz

This study experimentally characterizes a radio-frequency (RF) terminator using burned rice husk as an absorber over 2–7.5 GHz. The terminator was constructed from a 50 mm × 30 mm × 30 mm hollow-steel casing with a SubMiniature version A (SMA) connector mounted on the front surface, while burned rice husk powder was poured directly into the internal cavity. According to the laboratory test report, the black rice-husk ash sample used in the study had a reported carbon content of 48% and a moisture content of 4.2%. Measurements were performed using a SIGLENT SVA1075X after one-port Open–Short–Load calibration. The operating criterion was defined as voltage standing wave ratio (VSWR) ≤ 2, equivalent to S11 ≤ −9.54 dB. The VNA documentation showed S11 = −9.42 dB at 3.17722 GHz. Because numerical sweep data were not retained, the threshold crossing was not interpolated and the lower operating boundary is conservatively reported at approximately 3.18 GHz. The lowest documented S11 was −50.74 dB at 5.377165 GHz, corresponding to a VSWR of approximately 1.006. At 7.4903 GHz, S11 remained −30.73 dB, and the response continued to satisfy the criterion up to the 7.5 GHz instrument limit. Thus, the observed operating range extends from approximately 3.18 GHz to at least 7.5 GHz, corresponding to a frequency span of ≥4.32 GHz within the measurement window. The result indicates the potential of a burned-rice-husk-filled one-port terminator for wide-range RF termination, while the measured response represents the complete device rather than the intrinsic absorber properties alone.