Technical Details

This section introduces the concepts and terms that are crucial for the understanding, implementation and use of Sixfab 5G Modem Kit

5G Modem Carrier HAT

The detailed specifications of the Raspberry Pi 5G HAT are provided below.


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Pin Descriptions

Pin NumberBCM PinPin NameDescription
33GPIO13SIM SelectIt is used to toggle between the nano SIM card and the embedded SIM.
Default state is LOW selecting nano SIM. Set to HIGH for embedded SIM. It requires module reboot using FCP pin.
13GPIO27Fan On/Off - PWM ControlThe pin turns on the FAN when set to HIGH. Default is LOW. PWM can control fan speed. In the included Raspberry Pi OS, fan is set to full speed at 60°C. At 50°C, fan turns off.
37GPIO265G Module FCPThis pin controls power on/off of the module. Setting it to HIGH powers off the module after 10 seconds. Setting it to LOW initiates power-on sequence of the module and is fully functional after 50 seconds. Default state of the pin is LOW.
40GPIO21User LEDWhen the pin is pulled HIGH, the LED lights up.
38GPIO20User ButtonThis pin is pulled to the default HIGH state. When the button is pressed, the pin is pulled to the LOW.
35GPIO19Power LED OffIf you want to turn off the Power LED, you can set this pin to HIGH. By default, the Power LED will always be on.
15GPIO22Power DisableSet the pin to HIGH to completely cut off power from the HAT, disabling power consumption. In case of module unresponsiveness, use this method to power cycle the HAT. Setting the pin to LOW supplies power to the HAT. Default state of the pin is LOW.


Layout image alt


  • POWER LED: The LED indicates power status of the HAT and can also be controlled via GPIO19. Refer to the pin descriptions table for instructions.
  • STATUS LED: The LED indicates the RF function of the module. Turns on when RF Function is on. Turned off when the SIM is not powered or RF function is disabled.
  • USER LED: It is a programmable user-LED that can be controlled from the GPIO21 of Raspberry Pi for debugging or just fun.


  • User Button: It is a programmable user button that is connected to GPIO20. It reads HIGH by default.

5G Module

The module used in 5G Modem Kit is the Quectel M.2 5G Sub-6 RM502Q-AE module.

Frequency Bands

5G NR SA Bands: n41 (2469-2690MHz), n77 (3300-3800 MHz), n78 (3300-4200 MHz),n71(617-698 MHz)
5G NR NSA Bands: n41

Data Speed

5G SA Sub-6: Downlink 4.2 Gbps; Uplink 450 Mbps
5G NSA Sub-6: Downlink 5.0 Gbps; Uplink 600/650 Mbps



Network Protocols



88.1 x 57.7 x 21.7 mm


The total weight of the HAT is 68.37 grams.


Sixfab recommends to use of official power adapters for the product. Use the power adapter included in the kit with the HAT. The detailed power analysis of the product will be updated here soon.

USB Bridge

The USB Bridge serves the purpose of connecting the 5G module with the USB 3.0 port of the Raspberry Pi. This design choice was made in favor of using a USB cable, as it provides a robust, aesthetic, and space-saving solution. Rather than a standard straight cable connection, the USB Bridge has been specifically designed with filtering components to ensure faster and more efficient data transmission.


This antenna has been specifically designed and produced by Sixfab engineers, focusing on 5G bands and frequencies, exclusively for the 5G modem kit.

The connections between the antenna and the 5G module are established using MHF4 connectors and custom-made MHF4 cables.

For in-depth technical specifications regarding the antenna, please consult the details provided below.

The designed 5G terminal antenna is 4X MIMO Micro-strip antenna, which operates over:

5G NR SA Bands: n41 (2469-2690MHz), n77 (3300-3800 MHz), n78 (3300-4200 MHz),n71(617-698 MHz)
5G NR NSA Bands: n41

Return Loss

Frequency (MHz)257935503750600
Value (dB)-14.1-14.3-14.62-3


Frequency (MHz)257935503750600
Value (dB)1.07:11.29:11.32:18.21:1

Ports Isolations

Frequency (MHz)257935503750600
Avg. Ports Isolations<-20<-25<-29<-40


BandsGains (dBi)EfficienciesPolarizations

Propagation Patterns