Outdoor 5G Omni Antenna | 698-4200MHz Wideband Pole Antenna

An outdoor omni antenna covering 698 to 4200 MHz has one job: to put a usable pattern around a mast whatever radio is later connected to it. That makes it a site component rather than an accessory, and it changes which specifications matter. The 250 mm radome, the single N-Type port and the 3 to 5.5 dBi gain belong to a wideband vertical omni that can sit above a small cell, a repeater or a subscriber unit, and the numbers that decide whether the installation works are the vertical beamwidth on each band, the match at the band edges, and how a 0.5 kg part behaves on a pole in wind. This page works through those in turn.

What an outdoor wideband omni is used for, and what it is not

The pattern is 360 degrees in azimuth and vertical in polarization, so the antenna serves everything around the mast and nothing in particular. That suits a yard, a marina, a construction site, a rural cluster of houses, or a rooftop where the direction of the subscribers is unknown or changes. It also suits the donor side of a repeater, where the serving cell is somewhere in the distance and the installer would rather not aim a panel, and the roof of a distributed antenna system where a remote unit needs to see the macro layer.

It is not a sector, a link antenna or a MIMO element, and the three exclusions follow from the same fact. There is no horizontal directivity, so it cannot reject a co-channel interferer behind the mast. The gain is 3 to 5.5 dBi, so a 5 km point to point link is outside its range. And there is one port with one polarization, so a 2x2 radio gets one chain from one antenna. Feeding two of these from a 2x2 radio works, but the two units need spacing: at least half a wavelength at the lowest frequency in use, which is 215 mm at 700 MHz, and in practice half a metre to a metre so that the two patterns decorrelate rather than duplicate.

698 to 4200 MHz from one 250 mm radome

Six to one is a wide ratio for a passive radiator, and the way it is reached explains the shape of the datasheet. At 698 MHz the wavelength is 430 mm, so the 250 mm rod is a little over half a wavelength and behaves close to a short dipole. At 4200 MHz the wavelength is 71 mm, so the same rod is three and a half wavelengths and behaves as a small collinear array. Nothing physical changes between those two cases; only the electrical length does, and every specification follows from it.

The radome diameter is 60 mm, which is 0.14 of a wavelength at the bottom of the band and 0.84 at the top. That ratio sets the bandwidth of the radiating structure and the wind load, and it does almost nothing for gain. A buyer who compares two wideband omnis should therefore compare their lengths first: the longer radome is the one that can hold a narrower vertical beam at the low end, and no amount of diameter compensates for a short one.

The five columns are five different antennas

The gain rises in five steps, 3, 3.5, 4, 5 and 5.5 dBi, and the vertical beamwidth falls in step from 65 to 45 degrees. That pairing is the signature of a radiator whose electrical length increases with frequency, and it means the single figure in a catalogue summary is always a peak. Applying the 41253 rule to each column makes the trend quantitative. At 65 degrees the estimate is 2.5 dBi against 3.0 published, half a decibel of margin. At 45 degrees the estimate is 4.1 dBi against 5.5 published, which is 1.4 dB.

That 1.4 dB gap deserves a question rather than an assumption. Either the vertical pattern at 3300 to 4200 MHz is narrower than the 45 degrees stated, or the top column is a peak figure while the lower ones are averages, or the azimuth pattern has enough ripple that a 360 degree assumption is optimistic. A measured pattern cut settles it in one page. The practical consequence for a deployment is simpler: never quote 5 dBi on a quotation for a 700 MHz site, because the column that applies there is 3 dBi with a 65 degree beam.

VSWR 1.5 in the middle and 1.8 at the edges

The match is 1.8 across 698 to 806 MHz, improves to 1.5 across 806 to 2700 MHz, and returns to 1.8 at 3300 to 4200 MHz. A VSWR of 1.5 is a return loss of 14 dB and a mismatch loss of 0.18 dB; 1.8 is 10.9 dB and 0.37 dB. The band edges therefore give away 0.19 dB compared with the middle, which is negligible on its own but locates the design centre of the matching network: somewhere near 1.5 GHz, with the two extremes reached by the tails of that match rather than by separate tuned sections.

For a link budget, enter the 0.37 dB figure rather than the typical one, because the channel that gets assigned is often the one at the edge. The feeder matters more than either. Ten metres of 5 mm coax costs roughly 1.5 dB at 700 MHz and 3.5 dB at 3.5 GHz, so a site that upgrades from a low band to a mid band service loses 2 dB in the cable while the antenna gains 2.5 dB. The net advantage of the higher column can be close to zero, which is why the cable belongs in the same comparison as the gain.

Pole mounting, radome and the questions the table does not answer

The mechanical figures are modest. The radome presents 0.015 square metres of frontal area, which at 40 metres per second wind is about 18 newtons, and the whole part weighs 0.5 kg. A pole clamp is enough, and the 250 mm length keeps the lever arm short enough that a stiff jumper will not work the joint loose. A drip loop below the connector is still worth fitting, because water running down a vertical radome arrives at the connector from above.

Two things the table does not state are worth asking about before an outdoor order. The first is the ingress protection rating: the radome is ABS and the operating range is minus 55 to plus 60 Celsius, but no IP figure appears, and the joint between radome and base is where water enters on a part of this shape. The second is passive intermodulation, which matters if the antenna is used on a DAS roof or near a high power transmitter and is not relevant for a single subscriber link. Ask for the third order figure at two 43 dBm carriers, and for the standard it was measured to.

Where the site needs a fixed narrow beam instead of a 360 degree pattern, the n78 fiberglass omni holds 8 degrees in elevation over 3400 to 3800 MHz with a 630 mm radome. Where the subscribers sit in one direction, the dual band sector antenna trades the 360 degree coverage for 14 and 16 dBi. The rest of the range, including the narrowband parts for a single operator, is grouped on the 5G antenna page.

Send your requirement to sales@rfelement.com with the band plan, the mounting height, the coverage radius and the radio port count, and we will confirm whether a wideband omni is the right pattern or whether a sector or a narrowband part will serve the site better.