433Mhz Helical Antenna

433Mhz Helical Spring Antenna

2.2dBi Gain Rf Communication Wireless Communication Solderable Type Copper Vibration Resistant 433 MHz Remote Control

     The 433MHz Helical Antenna is a spring type antenna wound from copper wire for wireless modules working in the 433MHz band. It provides 2.2dBi gain in the 433MHz ±6MHz range and its input impedance is 50ohm. The straight leg at its lower end is soldered directly to the antenna pin of the module or to the antenna pad on the circuit board; no connector or cable is needed.

     At 433MHz the quarter wavelength is about 173mm; the spring winding fits this length into about 22mm height and about 5mm outer diameter. The antenna therefore fits inside enclosures and small devices such as remote controls and sensors. The winding, weighing about 0.5gr, is vibration resistant and can be used with up to 30dBm (1W) transmitter power.

     It is used with 433MHz modules such as the HC-12 serial wireless module, the Ra-02 (SX1278) LoRa module, the CC1101 433MHz module, 433MHz receiver-transmitter pairs and 4 channel RF remote control receivers; it is common in garage door and shutter remote controls, alarms, wireless sensors and telemetry devices.

Key features:

     Wound for 433MHz: The winding is made for the 433MHz ±6MHz band; with 2.2dBi gain and 50ohm impedance it matches the antenna output of 433MHz modules.

     Short height: Instead of a quarter wave antenna of about 173mm, a spring of about 22mm height is used; it takes little room in small enclosures.

     Direct solder: The straight leg is soldered to the ANT pin of the module or to the antenna pad on the board; no connector, cable or extra part is needed.

     Copper spring structure: The spring wound from copper wire is vibration resistant; it can be used up to 30dBm (1W) transmitter power.

Features:

• Product type: Helical (spring type) antenna, soldered to the PCB
• Frequency: 433MHz (433MHz ±6MHz)
• Gain: 2.2dBi
• Input impedance: 50ohm
• Maximum power: 30dBm (1W)
• Connection type: Solderable straight leg, no connector
• Radiation: In all directions around the antenna axis (omnidirectional)
• Quarter wave equivalent: about 173mm at 433MHz; the spring winding reduces it to about 22mm height
• Compatible modules: HC-12, Ra-02 (SX1278), CC1101 433MHz, 433MHz receiver-transmitter pairs, 4 channel RF remote control receivers
• Structure: Spring wound, vibration resistant
• Operating temperature: -40°C - +85°C
• Mounting: Soldered upright to the ANT pin of the module or to the antenna pad on the board
• Material: Copper wire
• Color: Copper
• Spring outer diameter: about 5mm
• Height: about 22mm
• Weight: about 0.5gr

Usage information:

• Solder the antenna to the ANT (antenna) pin of the module or to the antenna pad on the board with a short leg; do not leave the leg between the antenna pin and the spring longer than necessary.
• Keep the antenna upright and away from metal enclosures, batteries and the large copper ground area of the board. The link is better when the receiver and transmitter antennas point the same way (both upright).
• Do not stretch or compress the spring; the winding pitch determines which frequency the antenna is tuned to.

Application areas:

•  Remote control receivers and transmitters
•  Garage door, garden gate and shutter remote controls
•  Wireless alarm and security systems
•  Wireless sensor and telemetry devices
•  Greenhouse, field and garden monitoring nodes
•  LoRa 433MHz (Ra-02, SX1278) links
•  HC-12 serial wireless communication
•  Smart home and home automation devices
•  Wireless door bells and call systems
   

Points to consider:

•  This antenna is for 433MHz. Its efficiency drops on an 868MHz or 915MHz module; use an 868MHz helical antenna for 868MHz modules.
•  A short spring antenna gives less range than a full size (about 17cm) wire or SMA rod antenna at the same frequency. If long range is needed, choose an antenna with an SMA connector.
•  Range drops noticeably inside a metal enclosure; place the antenna in a plastic part of the enclosure or outside it.
•  Do not operate a transmitter module without an antenna; reflected power can damage the transmitter.

Package contents:

•  1 pcs 433MHz Helical Antenna
•  Note: The wireless module is not included in the package.