Modules, Boards & Gateways · Hardware
Industrial RF Antenna Series
Range is set by the antenna, not the radio — the right antenna, matched to the product.
Overview
The problem. Most field failures in wireless control systems come from the antenna, not the radio: a whip antenna stuck to a metal cabinet, a cheap antenna for the wrong band, a long lossy cable, a loose connector, a pigtail that has taken in water. Users look for a stronger radio because “the range is not enough”, yet a 3 dB gain difference or raising the antenna by 2 m gives the same result. Gain claims of imported antennas are often unverified.
The solution. The Elmes antenna series is an accessory list matched to Elmes products, with a defined band and connector for every item: omni whip antennas for inside and outside the cabinet (standard), a directional Yagi for remote points (433 MHz, 8.9 dBi declared), a vertical J-pole at 868 MHz, plus mounts and cable sets. For Elmes Module Series customers, u.FL pigtail and SMA options are on the same list. The goal is for every product page to link to this list through a “recommended antenna” row, with range tables naming the antenna used for the measurement.
Gain values. Gains in the tables are manufacturer datasheet claims. Elmes measurements are published separately, together with the measurement conditions, as they are completed.
Features
- Defined band and connector: band, connector and cable length of every antenna are listed; 433 and 868 MHz antennas are not mixed up.
- Yagi feed board: Elmes-designed feed PCB and profile drawings; local manufacturing option.
- J-pole housing drawing: Elmes housing design; local manufacturing option.
- Mount set: sheet-metal antenna bracket, ground-plane mast mount and Yagi mount; production drawings ready.
- TargetProduct matching table: a standard, long-range and in-cabinet antenna row for every Elmes product; range values are measured with that antenna.
- TargetPigtail and connector standard: u.FL + antenna pin on the module, female SMA on the carrier board, male SMA on external antennas (Elmes Module Series, I/O Carrier Boards).
- TargetOn-site measurement service: antenna alignment and an RSSI map at the customer site, together with installation and commissioning.
Antenna models
| Model code | Type | Band | Gain (declared) | Connector | Status | Request a quote |
|---|---|---|---|---|---|---|
| EL-AJP868-1 | J-pole, vertical; 360° in the horizontal plane | 850–900 MHz | 6 dBi (datasheet) | BNC, 2.5 m RG-58 | In the field | Request a quote: EL-AJP868-1 |
| EL-AYU447-4 | Yagi, 4-element, directional | 430–455 MHz | 8.9 dBi (datasheet) | TNC / BNC / N | In the field | Request a quote: EL-AYU447-4 |
| Omni 433 SMA | Whip omni | 433 MHz | 2 dBi | Male SMA | Standard accessory (modules and carrier boards) | Request a quote: Omni 433 SMA |
| ERA101Target | Short whip antenna | 433 / 868 MHz | To be set by measurement | Male SMA | Planned | Request a quote: ERA101 |
| ERA103Target | ERA catalog model | 433 / 868 MHz | To be set by measurement | Male SMA | Planned | Request a quote: ERA103 |
| ERA105Target | ERA catalog model | 433 / 868 MHz | To be set by measurement | Male SMA | Planned | Request a quote: ERA105 |
| ERA203Target | ERA catalog model | 433 / 868 MHz | To be set by measurement | Male SMA | Planned | Request a quote: ERA203 |
| ERA401Target | Outdoor mast-type antenna | 433 / 868 MHz | To be set by measurement | Male SMA | Planned | Request a quote: ERA401 |
| ERA802Target | ERA catalog model | 433 / 868 MHz | To be set by measurement | Male SMA | Planned | Request a quote: ERA802 |
| AL-103Target | ERA catalog model | 433 / 868 MHz | To be set by measurement | Male SMA | Planned | Request a quote: AL-103 |
Specifications
Values marked “Target” are design targets, next-generation values or chip-vendor data; they are updated as measurement and certification are completed.
| Frequency / bandwidth | 850–900 MHz / 50 MHz |
|---|---|
| Gain | 6 dBi (datasheet claim)Target |
| Beamwidth H / V | 360° / 15° |
| VSWR | < 1.5 |
| Impedance / polarization | 50 Ω / vertical |
| Max. power | 100 W |
| Connector options | TNC / BNC / N |
| Supplied connector / cable | BNC / 2.5 m RG-58 |
| Size / weight | 20 × 600 mm / 0.25 kg |
| Wind rating | 60 m/s |
| Operating temperature | −20…+55 °C |
| Mounting | U-bolt clamp |
| Type | 4-element, directional |
|---|---|
| Frequency band | 430–455 MHz |
| Gain | 8.9 dBi (datasheet claim) |
| Connector | TNC / BNC / N |
| Impedance / VSWR | 50 Ω / < 1.5Target |
| Frequency / gain | 433 MHz / 2 dBi |
|---|---|
| VSWR | < 1.5Target |
| Connector | Male SMA |
| Cable loss | RG-58: ~0.35 dB/m @ 433 MHz, ~0.5 dB/m @ 868 MHz (approx., cable datasheet) |
|---|---|
| Recommended cable length | ≤ 5 m with RG-58 (≈ 2–2.5 dB loss); for longer runs, LMR-200/400 or move the radio closer to the antenna |
| Lightning protection | Gas-discharge arrester + grounding for outdoor antennas |
| Warranty | 2 years, same as the product it is used with; mechanical damage and water ingress excludedTarget |
|---|
Applications
- Crane and machine control
- Well/tank telemetry
- RS485 modem links
- Gateways and sensor nodes
- EM module integration
- Remote point-to-point links
- In-cabinet and outdoor installations
| Situation | Recommended antenna |
|---|---|
| Inside the cabinet, short distance | Omni whip antenna (Omni 433 SMA) |
| Between buildings or across a site | External omni antenna on a mast |
| Single remote point (1 km+) | Yagi at both ends (EL-AYU447-4) |
| 868 MHz products | J-pole (EL-AJP868-1) |
In the field, J-pole 868 and Yagi 433 antennas are used in Wireless RS485 Modem installations, and omni antennas with ground-plane mast mounts at Wireless Crane Control System and Wireless Well & Tank Control System sites. For outdoor antennas, a gas-discharge lightning arrester and proper grounding are recommended.
Compliance & documentation
Antennas are passive components and need no separate RED certificate. Antenna gain enters the ERP calculation in the RED file of the radio product it is used with: the ERP limit at 868 MHz is 14 dBm.
- Out of scopeSeparate RED certificate (passive antenna)Assessed in the RED file of the radio product
- TargetAntenna gain and ERP calculation in product RED files
- TargetElmes gain and VSWR measurement reports
- TargetRoHS declaration (supplier)
- TargetOmni 433 datasheet and mounting instructions
Frequently asked questions
Which antenna should I choose?
Short distance inside a cabinet: an omni whip. Between buildings or across a site: an external omni on a mast. A single remote point (1 km+): a Yagi at both ends. For 868 MHz products: a J-pole. Tell us your product and the distance, and we will help you pick the right antenna.
Is higher gain always better?
No. Higher gain narrows the beam; alignment becomes essential and the vertical angle shrinks (a problem when the two ends are at different heights). Also, the ERP limit at 868 MHz (14 dBm) takes antenna gain into account.
How can the range be extended?
In this order: raise the antenna, move it away from metal, shorten the cable, use a directional antenna, and only then increase output power.
Will a 433 MHz antenna work on an 868 MHz product?
No. VSWR rises, range collapses and the radio may be damaged. Check the band on the label.
Have the gain values been measured?
The values in the tables are manufacturer datasheet claims. Elmes measurements are published separately with their measurement conditions as they are completed; unmeasured values are shown only as “declared”.
How long can the cable be?
Up to 5 m with RG-58 (≈ 2–2.5 dB loss). For longer runs, use LMR-200/400, or move the radio closer to the antenna and extend the data cable instead.
Is lightning protection needed?
For outdoor antennas, yes: a gas-discharge arrester and grounding; otherwise there is a risk of damage not covered by the warranty.
What about the warranty?
A 2-year warranty is planned (the same as the product it is used with); mechanical damage and water ingress are excluded.
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