Note: The 8-channel gateway version requires one band-pass filter, and the 16-channel gateway version requires two band-pass filters.

The RAK Outdoor Cavity Band-Pass Filter is an RF accessory designed to enhance LoRaWAN gateway performance in environments with high interference. It allows only the target LoRa frequency band to pass while attenuating out-of-band signals such as LTE, 5G, radar, and industrial noise.

The filter is based on a high-Q resonant cavity design, isolating the target frequency band and reducing the impact of external interference. This ensures stable and reliable gateway performance in urban and industrial deployments where RF noise is significant.

Features:

High out-of-band rejection: >75 dB attenuation to suppress LTE, 5G, radar, and other signals.
Low insertion loss: 2.0–3.2 dB (model dependent), preserving LoRa signal strength.
Easy integration: Standard N-Female connectors, no adapters required.
Available frequency variants: EU868, US915, IN865, RU864, AU915, KR920, AS923-1/2/3/4, CN470.

Specifications:

Interfaces

The band-pass filter provides the following interfaces:

Name: Description
N-Female Connector (Port 1): Connects the filter to the LoRa gateway via RF coaxial cable.
N-Female Connector (Port 2): Connects the filter to the external LoRa antenna.
Ground Pad: Provides connection to earth ground for ESD and surge protection. Strongly recommended.

Band-pass filter interfaces

What Is a LoRaWAN Cavity Band-Pass Filter?

A LoRaWAN Cavity Band-Pass Filter like the RAK Outdoor Cavity Band-Pass Filter is a hardware component that allows only the desired LoRaWAN frequency band to pass through, while attenuating nearby unwanted signals such as LTE, 5G, radar, or train communication systems.

It uses high-Q resonant cavities to isolate the target band, protecting LoRa gateways from strong external interference. This is particularly important in high-noise, urban, or industrial environments.

The RAK outdoor RF filter for gateways for LoRaWAN is designed to work with the following RAKwireless gateways:

And other brand gateways using standard N-Female RF connectors

When to Use a Cavity Band-Pass Filter with a Gateway for LoRaWAN

Near Cellular Towers – Prevents strong LTE/5G signals (700–900 MHz) from desensitizing the LoRa receiver.
Industrial Sites – Filters out wideband RF noise from heavy machinery, telemetry, or private radios.
Smart City Rooftops – Blocks interference from FM radio, TETRA/P25 public safety radios, or WiFi mesh.
Co-location with Other ISM Devices – Avoids spurious interference from Zigbee, alarms, or SRDs sharing ISM bands.
Agriculture Near Radar / Military Installations – Protects against high-power pulsed radar signals.
Dense Gateway Environments – Prevents cross-interference when multiple radios share the same mast.
Rural Long-Range Towers – Suppresses strong distant broadcast signals (FM, DVB) that raise noise floor.

Key Features of RAK Outdoor Cavity Band-Pass Filter

>70-80 dB attenuation outside the passband, effectively suppressing nearby LTE/5G/RF noise
Low insertion loss (<2.0–3.2 dB depending on model)
Fully sealed for rain, snow, dust, and high humidity environments
Easy integration with existing RF hardware. No adapters needed.
Supports global LoRa deployments: EU868, US915, CN470, IN865/RU864/AU915/KR920/AS923-1/AS923-2/AS923-3/AS923-4

Key Benefits of RAK Outdoor Cavity Band-Pass Filter

This filter improves network reliability and ensures LoRa signal noise suppression, giving operators clearer signal performance and consistent results in varied deployment environments.
Reduces troubleshooting caused by unpredictable RF noise
Improves consistency of network data delivery
Helps extend useful life of deployed gateways
Supports planning in mixed urban and industrial landscapes
LoRa signal noise suppression

Use Case #1: Smart City Gateway Near a Cellular Tower

Customers deploying LoRa gateways near LTE towers have observed a significant reduction in packet loss after adding the RAK Outdoor Cavity Band-Pass Filter. In many cases, packet loss dropped from double-digit percentages to nearly zero, and overall network reliability improved, with gateway-connected applications such as street lighting and traffic sensors achieving more than 99% service availability.

Use Case #2: Industrial Facility with Heavy Equipment

An energy plant operating welding and motor-heavy equipment used the RAK Cavity Filter to stabilize its LoRa network. It reduced interference-related data errors and maintained consistent uplink success rates across the facility.

Documentations:

Package Includes: