900MHz Yagi Antenna | GSM Yagi Antenna | 14dBi Gain

A 900 MHz Yagi with 14 dBi of gain on a 1350 mm aluminium boom, 185 mm wide and 65 mm deep, weighing 1.1 kg. The horizontal beam is 40 degrees and the vertical beam 35 degrees, VSWR is at or below 1.5 across 824-960 MHz, and the single port is an N-Type male connector rated at 50 W. It is the longest Yagi in the 900 MHz range, intended for fixed links where the mast can carry a 1.35 m boom.

Boom length is the gain

A Yagi produces gain by adding director elements along the boom. Fourteen decibels at 900 MHz needs roughly 1350 mm of boom, which is why this antenna is the longest in the 900 MHz family. The 12 dBi version uses 800 mm and the dual-polarised 11 dBi unit uses 1020 mm for two interleaved arrays.

That relationship sets the practical trade. If the mounting point cannot carry a 1.35 m boom, the 12 dBi antenna is the realistic alternative, and the 2 dB difference in gain costs about 20 percent of the coverage radius. It is rarely worth forcing the longer antenna onto a weak bracket.

The 824-960 MHz span

Covering 136 MHz at 900 MHz is a wide requirement for a Yagi, and the VSWR of 1.5 or better across the whole span is the specification that makes this antenna useful for mixed deployments: GSM 850, GSM 900, the 900 MHz ISM band, SCADA and LPWAN all fall inside it. A narrower Yagi optimised for 900-930 MHz would give slightly more gain for the same boom length but would not cover 850 MHz.

If the site only uses the 900 MHz ISM band, the narrower antenna is the more efficient choice. If the site has a mixture of licensed and unlicensed services, this one removes the need for two antennas on the mast.

A 1.35 m boom on a mast

Wind load on a Yagi comes from the boom and the element tips rather than from a solid surface, so the load is lower than a panel of similar gain. The moment arm, however, is longer. Clamp the boom at two points at least 400 mm apart and orient the elements horizontally or vertically according to the link, not according to what is convenient for the bracket.

At 1.1 kg the antenna is light for its length, which is an advantage on a slim mast but also means it can rotate if the clamp is not tight. Mark the boom and the pole with a alignment line before final tightening so that a later inspection can confirm the antenna has not moved.

Where 14 dBi fits

For a SCADA or telemetry link of 5 to 15 km, 14 dBi at both ends with a clear path is a comfortable design. For a shorter link of 1 to 3 km, the same antenna works but the beam is narrower than necessary, and a 10 to 12 dBi unit is easier to aim. For a multipoint LPWAN gateway serving sensors across a 90 degree arc, a Yagi in any gain class is too narrow and a sector antenna is the correct part.

The vertical beam of 35 degrees is wide enough that mounting height is not critical. That is a useful property for a site where the pole height is fixed by other equipment and cannot be chosen for the link.

Ordering

N-Type male is standard, with packing quantity confirmed at order. Samples in 3-5 days, production in 15-25 days.

Where the boom length is a constraint, the 12 dBi GSM Yagi antenna covers the same 824-960 MHz range with an 800 mm boom and a 55 degree beam. Where a 2x2 radio needs two polarisations at 900 MHz, the 11 dBi 900 MHz MIMO Yagi antenna interleaves both arrays on one stainless steel boom.

Send the link distance, the band plan and the mounting height. The band plan decides whether the 136 MHz span of this antenna is needed or whether a narrower Yagi would deliver more gain.