Broadband Omni Antenna 1–8 GHz — Gain, Radiation Pattern and SWR
Lab-measurement report for the broadband omnidirectional Omni 1–8 GHz antenna: gain versus frequency, the radiation pattern at 5800 MHz and the SWR match across the operating band. Measurements taken at 1 m.
In-band gain. The swept measurement (combined H+V polarisation, 1 m distance) shows a flat broadband response across 1–8 GHz with no sharp dropouts in the operating band. Azimuth-plane gain stays near 0…+1 dBi at the band edges (0.9 GHz: −0.4 dBi; 1.2 GHz: +0.2 dBi; 5.8 GHz: +1.0 dBi), consistent with an omnidirectional radiator.
Radiation pattern (5800 MHz). A three-axis measurement (72 steps) confirms a near-omnidirectional response in the horizontal plane: in the XY plane the gain is uniform (min 2.7 / max 6.1 / avg 4.8 dBi). Across the three planes the peak gain reaches 8.8 dBi, directivity is about 3.6 dBi and efficiency about 30 %. The pattern is toroidal, with the expected nulls along the antenna axis.
Matching (SWR). Vector-network-analyser S-parameter measurements show a good 50 Ω match across the whole operating band: SWR < 2 from ~1 to 8 GHz (0.99 GHz: 1.35; 2.42 GHz: 1.87; 4.18 GHz: 1.25; 6.46 GHz: 1.38; 7.87 GHz: 1.55). Acceptable matching is maintained to roughly 10 GHz; above that is out of band.
Summary. The antenna delivers stable broadband omnidirectional coverage over 1–8 GHz with uniform azimuth gain and a good match, which makes it suitable for ground stations, SDR receivers, spectrum analysers and radio-monitoring systems.
