434 MHz Water Resistant Antenna with SMA ConnectorANT-400-R

The ANT-400-R is a 3/8 λ non-directional antenna for the 434 MHz band. The external cover uses elastomeric material which has good weather resistance. The metal base part can be fixed to the housing of the product.


  • 3/8 λ non-directional antenna for the 434 MHz band.
  • Weather proof for outdoor use

Connection Examples

ANT-400-R Mounted on Case

Example of use with ANT-400-R and CDP-RX-02
When using a plastic case connect the antenna base of the ANT-400-R with a metal ground plane for antenna impedance matching. A wider ground plane is more effective for receiver sensitivity and stability.

In order to avoid influence from noise, the coax cable must be placed far away from the CPU and PCBs.

The above picture shows the antenna connected to the radio module through CBL-SMA-05-R. When using a dedicated coaxial cable for the connection, make the cable short to avoid loss from the cable and influence from external components.

ANT-400-R Outdoor Installation

To achieve long distance and stable communication, placing the antenna high up will provide good RF visibility for such purpose. By moving the antenna in this location and using weatherproof coaxial cable, the main control unit can be placed away into a more accessible area for easier maintenance.

The SMA receptacle attaches to the inside wall of the unit and then connected to the extension cable. The exterior coaxial cable extension needs to be of the weatherproof type. The end of this cable going to the unit uses female SMA connector. The end going to the antenna uses male SMA connector. Use heat shrink and insulating tape over the SMA connectors to protect against corrosion and water.


Parameter Specification Remarks
Frequency band 410 to 450 MHz SWR ≤ 2
Antenna type 3/8 λ
Impedance 50 ohms
VSWR ≤ 2
Gain ≤ 2.15 dBi
Connector SMA
Length 184 mm (Antenna)
13.2 mm (Antenna base)
Includes a connector
Weight 45 g
Attachments Nut, washer

External View

SWR Characteristics

Smith Chart


Data Sheet

Version 1.1