Spis treści
This page shows how to use with builtin power amplifier stage, external to the radio transceiver itself. The basic concept of these modules is that the power output of single-chip transceivers is limited, usually at around 20 dBm. To get higher output power, such as 30 dBm, an external PA is required. The overall simplified architecture of the high-power module then looks like this:
+--------------------------------------------+
| High-power module |
| |
| +----------------+ +-------------+ |
SPI <---> | Transceiver IC | ---> | External PA | ---> Antenna
| +----------------+ +-------------+ |
| |
| |
+--------------------------------------------+
RadioLib can only interface with the transceiver IC. The rest of the setup (external PA, filters, RF switches etc.) can be entirely different on each module, and so it's up to the user to know the gain of the external PA that's being used, and to set the correct output power in RadioLib.
The power level to set in RadioLib (usually via setOutputPower() method) can be calculated in the following way:
P_radiolib [dBm] = P_total [dBm] - A_pa [dB]
where P_radiolib is the power output to be set in RadioLib in dBm, P_total is the targeted total output power in dBm (usually 30 dBm) and A_pa is the gain of the external PA in dB.
List of high-power modules
The following is a list of all currently available high-power radio modules, with PA part numbers (if available).
- Ebyte E22-400M30S
- SX1268 LoRa module, 400 MHz band
- H0606E PA, roughly +12.5 dB gain (frequency-dependent, see datasheet)
- Ebyte E22-900M30S
- SX1262 LoRa module, 900 MHz band
- YP2233W PA, +7.25 dB dB gain
- See https://github.com/S5NC/EBYTE_ESP32-S3/blob/main/power%20testing.txt for measured gain
- Ebyte E220-900M30S
- LLCC68 LoRa module, 900 MHz band
- YP2233W PA, +7.25 dB dB gain
- Dorji DRF1268TL
- SX1268 LoRa module
- unknown PA
- G-Nice RF 1268F30
- SX1268 LoRa module
- unknown PA
- HopeRF RFM98PW
- SX1278 LoRa module
- unknown PA