868Mhz Helical Antenna

868Mhz Helical Spring Antenna

2.15dBi Gain Rf Communication Wireless Communication Solderable Type Copper Vibration Resistant 868 MHz Remote Control

     The 868MHz Helical Antenna is a small spring (helical) shaped antenna wound from copper wire for the 868MHz band. It operates in the 868MHz ±5MHz range, with 2.15dBi gain and 50ohm impedance; its VSWR is 1.5 or lower. With a height of about 13mm and a wire diameter of 0.8mm, it fits into small enclosures and circuit boards where a long rod antenna does not fit.

     The straight leg at its lower end is soldered directly to the antenna pin of the wireless module or to the antenna pad on the circuit board; no connector or cable is needed. The copper spring structure is resistant to vibration, and at about 1gr it adds no load to portable devices.

     It suits the antenna output of modules working at 868MHz such as LoRa (SX1276 / SX1262 based), CC1101 and RFM69 / RFM95. It is used in 868MHz applications such as wireless alarm sensors, meter reading, remote control, LoRaWAN sensor nodes and Meshtastic devices. It is tuned only for 868MHz; it is not used on 433MHz or 915MHz devices.

Key features:

     Tuned to 868MHz: Spring length and number of turns are made for the 868MHz band; it matches a 50ohm output with VSWR of 1.5 or lower in the 868MHz ±5MHz range.

     Very small: About 13mm high and about 1gr; it stands upright on the board, fits inside the enclosure, and no external rod antenna is needed.

     Direct solder: The straight leg at the lower end is soldered to the module ANT pin or the antenna pad on the board; there is no connector loss and no cable.

     Copper spring build: Wound from 0.8mm copper wire; it is resistant to vibration and suitable for up to 5W power.

Features:

• Product type: 868MHz spring (helical) antenna, PCB solder type
• Model: 868MHz Helical Antenna
• Frequency range: 868MHz ±5MHz
• Gain: 2.15dBi
• Impedance: 50ohm
• VSWR: ≤1.5
• Maximum power: 5W
• Polarization: linear (vertical when the antenna stands upright)
• Connection type: direct solder (straight solder leg at the lower end), no connector
• Compatible modules: 868MHz LoRa (SX1276 / SX1262 based), CC1101, RFM69, RFM95 and other modules with an 868MHz antenna output
• Operating band: European 868MHz SRD / ISM band
• Vibration resistance: copper spring build, suitable for vibrating environments
• Material: Copper wire
• Color: Copper
• Wire diameter: 0.8mm
• Height: about 13mm (excluding solder leg)
• Weight: about 1gr

Usage information:

• Solder the straight leg at the lower end of the antenna to the module ANT pin or to the pad at the end of the 50ohm antenna track on the board. Solder quickly and do not compress the spring while soldering.
• Leave the antenna upright and free from the board plane; make sure there are no metal parts, batteries or cables close to it (within a few cm). If the antenna is inside an enclosure, use a non-metal (plastic) enclosure.
• Use 868MHz antennas at both ends; range is best when the antennas of the communicating devices point the same way (both upright).

Areas of use:

•  LoRa and LoRaWAN sensor nodes
•  Meshtastic messaging devices
•  Remote reading of water, electricity and gas meters
•  Wireless alarm and security sensors
•  Remote control, garage and garden gate remote control
•  Smart home and home automation devices
•  Greenhouse and field sensors, irrigation control
•  Telemetry and remote monitoring devices
•  Wireless circuits with CC1101 and RFM69 / RFM95 modules

Precautions:

•  This antenna is tuned only for 868MHz. 433MHz devices need a 433MHz helical antenna; on 915MHz devices efficiency drops.
•  Do not stretch or compress the spring; if its length changes, the tuned frequency shifts and range drops.
•  Antenna efficiency depends on the ground (GND) area on the board and on nearby metal parts; the 2.15dBi and VSWR values are seller data and may differ on your board.
•  Do not operate a transmitter module without an antenna; the output stage may be damaged.

Package contents:

•  1 pcs 868MHz Helical Antenna
•  Note: The wireless module is not included in the package.