Antenna choice starts at the modem
Choose for your modem, operator and installation. Raspberry Pi and Radxa use the same radio principles: the modem’s RF ports determine which antenna connections are needed. MIMO is a modem/network capability, not a UAS dashboard setting.
Reviewed: 3 November 2026. Source links appear beside the technical guidance and product examples.
Built-in, external, or no antenna?
No external antenna does not mean no antenna.
A USB dongle may already contain working antennas. A bare modem module usually needs the antennas specified by its hardware guide. Compare the original working arrangement with a properly connected external setup; do not use a disconnected required MAIN port as the baseline.
An external antenna can help when it moves reception away from shielding, improves coverage of the operator's bands, or provides a better-positioned RF path.
It may bring little benefit when the existing RF connection is already good, the cell is congested, or the SIM plan limits speed. A poor antenna, unsuitable mounting or lossy cable can make things worse.
There is no universal “+X Mbps” or extra range from adding an antenna. Compare sustained upload, stability and video delay in the real installation.
Choose the antenna type for the job
- Whip / swivel antenna: compact and easy to fit. Its shape alone does not establish quality; check its genuine cellular specifications.
- Flexible PCB / adhesive antenna: useful inside a suitable non-metallic enclosure. Mounting clearance and cable routing matter.
- Omnidirectional external antenna: useful where the serving tower's direction changes. “Omni” usually describes horizontal coverage, not equal performance in every 3D direction.
- Directional panel / LPDA / Yagi: aims coverage toward a chosen direction. Usually easier to use at a fixed ground installation than on a turning aircraft.
- Combined MIMO enclosure: contains separate antenna elements/feeds. Extra cables may also belong to Wi-Fi or GNSS—read their labels.
Small antennas are not automatically bad, and a large enclosure is not proof of good performance. Use measured gain/efficiency/pattern data for the frequencies you need.
Read the specification, not “full-band”
Wideband does not mean maximum gain at every frequency.
Look for the exact operating ranges, efficiency and radiation patterns across those ranges, impedance, connector and mounting requirements. Peak gain is the best value under specified conditions—not the gain in every direction or at every band.
A multiband antenna may use several resonances in one structure. It does not necessarily contain a separate patch antenna for every band.
Lower-frequency performance can be sensitive to antenna size and the surrounding structure. There is no universal “10 cm is enough” rule. Ground-plane requirements are design-specific; an antenna intended for a metal mounting plane and a ground-independent adhesive antenna need different installations.
Examples from the original project
These project photos are retained as physical examples—not as measured gain certificates.
The first antenna is labelled 698–960 / 1710–2690 MHz. That label does not establish coverage of 600 MHz cellular service or 3.5 GHz 5G. “Full Band LTE” printed on it must not be read as “all worldwide LTE/5G bands”.
The second photograph does not provide an identifiable part number or a readable frequency/gain specification. Confirm its datasheet before selecting it for a new operator or modem.
A good result in one installation is useful experience, but it does not replace checking the bands and testing the final placement. Compare your operator's requirements in Bands and regions.
MIMO, diversity and a single antenna
MIMO = Multiple Input Multiple Output. Independent radio paths can carry separate spatial streams when the modem, network and radio conditions support them. Diversity uses different received paths to reduce fading; it is related, but not the same as multiplying data streams.
2×2 / 4×4
These describe supported radio arrangements, not a guaranteed 2×/4× speed increase. Each required RF path needs its own correct antenna connection. A splitter does not turn one modem port into MIMO. Poynting: independent MIMO feeds ↗.
For UAS video, upload matters. Some LTE modules use MAIN for transmit/receive and DIV for receive diversity. A second antenna therefore does not automatically create a second uplink transmitter. Quectel EG06 is one documented example. Hardware guide, antenna interfaces ↗.
A genuine single-antenna/SISO device cannot gain MIMO through a dashboard setting. On a multi-antenna modem, omitting required feeds can sacrifice performance; follow that model's port map.
Positioning two antennas
Use a designed pair or a documented MIMO antenna.
Both cellular paths should cover the bands required by their assigned ports. Do not deliberately choose mismatched bands just so one antenna “covers the other's weakness”.
Separate elements need suitable isolation and sufficiently different received paths. Orientation and spacing depend on the design, frequency and installation. Common cross-polarised arrangements include +45°/−45° or 0°/90°; they are not a universal instruction to rotate every PCB by 90°.
A combined MIMO enclosure may already set the element orientation internally. Follow its mounting guide. Do not copy a mast-antenna spacing distance onto a small embedded antenna.
Keep antennas clear of shielding and noisy electronics; secure the coax so movement does not pull on tiny RF connectors. Check performance with the enclosure closed and the aircraft in different orientations.
Poynting: polarisation and different received paths ↗ · Taoglas: placement affects efficiency ↗.
Cable loss and connector compatibility
Use the exact connector and a suitable 50 Ω RF path specified for the modem.
- SMA and RP-SMA have different centre-contact arrangements; matching threads are not enough.
- Verify TS9/CRC9 or miniature connector variants from the device drawing. “I-PEX” alone is not a complete connector specification.
- Keep coax short; compare loss at your actual frequency, not only a cable's length.
- Avoid unnecessary adapters and passive splitters. Route cables without sharp bends or strain.
- Connect cellular, Wi-Fi and GNSS leads only to their designated ports. A shared-looking connector does not make their antennas interchangeable.
Illustrative RF budget: 6 dBi antenna gain − 3 dB cable loss − 0.5 dB adapter loss leaves 2.5 dB in that direction, before other installation effects. These example values are not measurements of the products below.
Taoglas: RF connector distinctions ↗ · Poynting: cable and splitter losses ↗.
Moving aircraft and fixed ground stations
Practical starting point for the aircraft
Choose lightweight antennas with a useful radiation pattern across changing headings and bank angles. A large peak-gain figure can hide weak directions. An omni pattern around the horizon still has an elevation pattern; assess both.
At a fixed ground installation, a directional antenna can be aimed toward a usable cellular site and tested. It is not automatically a good choice on an aircraft that continually turns.
UAS uses the mobile network: the aircraft's modem communicates with the operator's base station. A cellular antenna on the ground station also serves its own network connection; pointing it at the aircraft is not the normal LTE/5G path.
Our application recommendation follows the mobility trade-off described by Poynting: why maximum gain can be the wrong choice for moving vehicles ↗. Final antenna placement still needs testing on your airframe.
Compact example: Taoglas FXUB63
FXUB63.07.0150C · flexible embedded element
The manufacturer specifies 600–6000 MHz, 96 × 21 × 0.2 mm, a 150 mm cable and an I-PEX MHF I / U.FL-compatible connector. It is intended for adhesive installation on a suitable non-metal surface.
This is a single antenna element, not a complete 2×2 MIMO system by itself. A multi-port installation needs the required number of elements, correct spacing and verified port connections.
Why consider this type?
Low mass and a thin form suit compact builds. Placement can still change its performance; do not attach it to metal simply because the description says ground-plane independent.
Selection example, not a UAS flight-tested guarantee. Check the exact cable/connector variant.
Official product and datasheet ↗. Photo: Taoglas.
External omni: Poynting OMNI-600-5G
2×2 MIMO · two cellular paths in one enclosure
The current manufacturer specification lists 410–4200 MHz, an omnidirectional design and IP65 protection. Read the radiation patterns and exact connector/cable option before purchase.
This is an example for a ground installation or a larger platform, not a recommendation to fit this mast-style antenna to every small aircraft. Its enclosure, mount and cable arrangement must suit the installation.
Connect both required cellular feeds to the matching modem paths. The antenna cannot add bands that the modem itself does not support.
Selection reference; UAS installation testing still required.
Official OMNI-600-5G specification ↗. Photo: Poynting.
Directional panel: Poynting XPOL-2-5G
Cross-polarised 2×2 MIMO panel
The current product page lists 617–4200 MHz, two cellular ports and IP65 protection. SMA-cable and N-type variants exist. Check the exact revision: older datasheets/reseller listings may show different coverage.
A sensible use case
A fixed ground modem with a known usable cellular direction, where the panel can be mounted and aligned. Compare signal quality and upload across candidate directions; the nearest visible tower is not automatically the best connection.
Not the default choice for a turning small aircraft. Its directional gain trades broad coverage for a preferred direction. The advertised peak gain is not uniform across all bands, and cable loss must be included.
Official XPOL-2-5G variants and patterns ↗. Photo: Poynting. This is a selection example, not a measured UAS range claim.
Measure the difference
Bars alone are not enough. Use the measurements exposed by the modem's own interface or supported diagnostics; the UAS Modem tab does not promise a complete RF analyser.
- RSRP (dBm): received reference-signal power. Less negative generally means stronger signal.
- RSRQ (dB): a received-signal quality measure; generally closer to zero is better.
- SINR (dB): wanted signal relative to interference/noise; higher is generally better.
- Record the band/cell, sustained upload, packet loss, delay under load and actual video behaviour.
A stronger RSRP with worse SINR or worse upload is not automatically an improvement. Published signal thresholds are rough guides, not universal pass/fail values for every modem and network.
For UAS, the objective is a stable uplink with video and telemetry running—not a single impressive download result.
A repeatable before-and-after test
- Record modem/firmware, SIM/operator, antenna model, ports, cables and placement.
- Measure the original working setup. Keep the same camera, codec, resolution, bitrate and receiver path.
- Change one antenna/mounting variable, reconnect correctly, then allow the connection to settle.
- Record band/cell and RF measurements where available. A cell or band change can affect the comparison.
- Compare several short upload/video tests, including delay while the link is busy. Repeat at similar times and in different orientations.
- Keep the arrangement that is consistently better; recheck after the enclosure and cables are secured.
No improvement? Check connector contact, band coverage, cable loss, shielding and required MIMO feeds. Congestion, coverage gaps or a restricted SIM plan may require a different network rather than another antenna.
Keep the combined video bitrate below the stable uplink. Antennas cannot remove all mobile-network delay or create automatic adaptive bitrate in UAS.
Modem workflow: Modem setup · Regional bands: Bands and regions.