9 dBi UHF RFID Panel Antenna

Beam size is not read range. The rectangle above is where the field is strong enough to power a tag. Whether the tag answers depends on the tag, the reader output, the cable loss and what the tag is attached to. A hard tag on a steel container will answer far further than a paper label on a shrink-wrapped pallet. Tell us the tag and we will give you a number, not the best case.

One note if you are comparing the two pages. The beams run the other way round: the 6 dBi unit is published at 42° by 38° and this one at 70° by 63°. Gain and beamwidth are two views of the same aperture, and a lower-gain antenna cannot have the narrower beam. If your installation depends on a tight beam at 6 dBi, ask us to confirm that figure against a measured pattern first.

Why the 9 dBi figure on this page can be trusted. Two independent checks, both arithmetic rather than opinion, and they agree:

Aperture. Directivity is capped by 4πA/λ². At 915 MHz, λ = 300 ÷ 0.915 = 328 mm. A 259 mm square gives A = 0.0671 m², so the ceiling is 4π(0.0671) ÷ 0.1075 = 7.84 → 8.9 dBi.

Beamwidth. For a rectangular beam, D ≈ 41253 ÷ (θH × θV). With 70° and 63° that is 41253 ÷ 4410 = 9.36 → 9.7 dBi.

The published figure, the aperture and the beam all land within a decibel of each other, which is what a real datasheet looks like.

IP67, read carefully. IP67 means dust-tight and protected against immersion in 1 m of water for 30 minutes. It is a claim about a sealed enclosure, and the only way into this enclosure is the coax socket. So the rating holds only if the cable is fitted with a properly sealed N-type joint — a mating plug with a gasket or a self-amalgamating tape wrap, and a drip loop so water cannot run down the cable into the connector. 

What a passive antenna does, and does not do

This is a passive directional antenna. It contains no receiver, no transmitter, no decoder and no software. It shapes the field a reader produces; it cannot read anything on its own.

That matters because the phrases most often written about antennas — “fast reading and writing speed”, “multi-label reading”, “long reading distance”, “high data security” — all describe the tag and the reader, not the panel. What this panel contributes is a wide 70° field, 9 dBi of gain in that direction, and 25 dB of rejection behind it, so a reader can inventory a whole gate in one pass and largely ignore the rack behind the antenna.

Jobs this size suits: a vehicle gate or lane, a two-lane portal, a wide conveyor mouth, a pallet bay, a tool or asset zone, a toll or weigh lane. Jobs it does not suit: a single personnel door, where the beam spills past the opening and reads tags in the next room; and a hand-held or counter application, where a smaller panel or an embedded ceramic antenna is the right part.

What read range will I get from a 9 dBi panel?

The beam, not the gain, is what the datasheet can tell you honestly: 7.0 m wide and 6.1 m high at 5 m, 14.0 m by 12.3 m at 10 m. How far a tag answers depends on the tag, the reader output, the cable loss and the material the tag is attached to. 

Can I use two of these facing each other as a portal?

Yes, and this is the size most portals use. Order them together and ask for matching handedness: a right-hand circular antenna facing a left-hand one rejects most of the signal between them, and that failure looks exactly like a badly tuned reader.

Circular or linear?

Circular. That means a tag reads at any orientation, which is why gate and portal work uses it. The cost is about 3 dB against a perfectly aligned linear tag, which works out to roughly 30% less usable distance at the same reader power.

What connector is on it?

An N-type female on a four-hole flange, as the rear photograph shows. Confirm it on the quote because it decides the jumper. N-type is the right choice at this size: it is weatherproof when correctly sealed, and it handles the power.

Is IP67 realistic with a connector on the back?

IP67 is a claim about a sealed enclosure and the socket is the only opening, so the answer depends entirely on the joint. Use a mating plug with a gasket or a self-amalgamating wrap and put a drip loop in the cable.

9 dBi or 12 dBi?

Wider and easier to aim against narrower and further. This panel covers a gate at 70° without careful alignment; the 12 dBi panel concentrates the same power into a much tighter beam for a long throw down an aisle or across a yard. If you are not sure, tell us the opening width and the mounting height and we will pick.

What do you need to quote?

The country and band, how many units and whether they will be used as a pair, the mounting height, the pole or structure you are fixing to, the cable run to the reader, and the tag you intend to read.