[Working frequency band]：410~493MHz
[Transmission power]： 37dBm
[Communication distance]：20km
[Receive gain]：15dBm
[Product size]：45*30mm
| Main parameter | Performance | Note | |||
| Min | Type | Max | |||
| Supply voltage (V) | 3.3 | 5 | 5. 5 | ≥ 4. 7V guaranteed output power | |
| PA control voltage (V) | 7.4 | 7.5 | 7.6 | 7.5V is recommended to ensure the best performance | |
| Operating temperature (℃) | -40 | 25 | +85 | Industrial grade design | |
| Operating frequency band (MHz) | 410 | - | 493 | ISM band | |
| Power waste | Emission current (mA) | 1400 | 1500 | 1600 | Instantaneous power 37dBm (power supply voltage 5V, PA voltage 7. 5V test) |
| Receiving current (mA) | 6.5 | 8 | - | -lOOdBm input current 8mA | |
| Sleep current ( u A) | 3.0 | T/RX_EN = 0 | |||
| Maximum transmit power (dBm) | 36 | 37 | 38 | The front stage input power is greater than 17dBm, which can ensure full power output | |
| Receive gain (dBm) | 14 | 15 | 17 | -lOOdBm input | |
| Main parameter | Description | Note |
| Reference distance | 20Km | Clear and open environment, antenna gain 5dBi, antenna height 2m, air speed 2. 4kbps |
| Packaging method | SMD | / / |
| Interface mode | 1. 5mm | Stamp hole |
| Overall dimensions | 45*30mm | / / |
| RF input/output interface | Stamp/IPX | Equivalent impedance about 50 Q |
| Main parameter | Performance | Note | |
| Min | Max | ||
| Supply voltage (V) | 3.3 | 5. 5 | Permanently burned modules over 6V |
| PA drive voltage (V) | 7.4 | 7.6 | Default 7. 5V power supply can output full power |
| Blocking power (dBm) | - | lOdbm | High burning probability of high-power module in close use |
| Operating temperature (eC) | -40 | +85 | Industrial grade |
3. Practical Application Scenarios
3.1 Long-Range Agricultural IoT & Smart Irrigation Backhaul
In large-scale farmland spanning several square kilometers, soil moisture sensors and weather stations based on Ebyte E22 LoRa nodes cannot reach a central gateway at 20 km line-of-sight by themselves. By inserting the E21-400G37S as a PA booster on both the field node and the gateway side, the 410-493MHz signal achieves 37dBm output with 15dB LNA receive gain, extending the wireless link to 20km in open terrain while maintaining the low-power LoRa modulation benefits. The industrial -40 to +85°C rating ensures year-round operation in harsh field environments.
3.2 Utility Grid Substation & Pipeline SCADA Communication
Power grid companies and oil/gas pipeline operators require reliable telemetry over 10-20km distances in suburban or remote corridors. The E21-400G37S pairs with a Sub-GHz transceiver front-end to amplify RTU (Remote Terminal Unit) signals to 37dBm, penetrating vegetation and绕射 around obstacles thanks to the 410-493MHz low-frequency band. The built-in limiter protects the receive channel from high-power proximity exposure, while the 7.5V PA drive and 5V control supply simplify integration into existing 12V/24V industrial DC systems via a buck converter.
3.3 Mining, Quarry & Heavy Industrial Site Connectivity
Open-pit mines and quarries demand rugged wireless data links between excavators, haul trucks and dispatch centers across 5-15km ranges. The E21-400G37S, mounted with adequate heatsink on its back-side copper pad, delivers 37dBm transmit power with 1.3A peak current draw at 5V. Its stamp-hole SMT package and 45×30mm footprint allow OEMs to embed it directly into vehicle-mounted telematics boxes, boosting the range of existing 433MHz/470MHz radio modems to cover the entire pit without repeater infrastructure.
3.4 Remote Weather Stations & Environmental Monitoring Networks
Meteorological bureaus deploy automatic weather stations (AWS) in mountains, islands and deserts where cellular coverage is absent. A solar-powered AWS uses the E21-400G37S alongside an E22 LoRa module to transmit data 20km back to a base station. The 3μA sleep current is critical for solar-battery autonomy, while the 37dBm PA burst ensures the short daily data uplink cuts through long distances with margin. The 410-493MHz band provides superior diffraction over hills compared to 2.4GHz alternatives.
3.5 Security Perimeter & Long-Range UAV Ground Control Links
Security system integrators building virtual perimeter detection around airports or border fences use PIR and microwave sensors networked via 433-470MHz. The E21-400G37S amplifies the sensor node's RF front-end to 37dBm, enabling a single collection point to cover a 20km perimeter segment. For UAV ground control, the same module boosts the 433MHz RC link, extending control range well beyond standard 2.4GHz RC systems while retaining the regulatory advantage of the lower ISM band.
4. FAQ Section
4.1 What is the difference between E21-400G37S and E21-400G30S?
The E21-400G37S delivers 37dBm maximum output power with 20km range and measures 45×30mm, whereas the E21-400G30S outputs 30dBm with 5km range in a smaller 27.5×18mm package. The G37S also features a dedicated 7.5V PA drive input and 1.2-1.4A transmit current, making it suitable for long-haul links, while the G30S is ideal for medium-range applications where power budget and PCB space are constrained.
4.2 What front-end RF input power is required to achieve 37dBm output?
The E21-400G37S requires a pre-stage input power of 20dBm to stably output 37dBm, with a typical transmit gain of 15-17dB. If your base transceiver outputs less than 20dBm, the final output will not reach the full 37dBm specification. This makes the module ideally paired with Ebyte E22 series LoRa modules or similar Sub-GHz transceivers capable of 20dBm output.
4.3 How should the TXEN and RXEN control signals be managed?
TXEN and RXEN are active-high control pins supporting 3.3V/5V logic. They must never be enabled simultaneously, as this will permanently damage the PA. In a typical TDD (Time Division Duplex) setup, the host MCU drives TXEN high during transmission and RXEN high during reception, with both low in sleep mode to achieve the 3μA standby current. A hardware interlock or MCU GPIO sequencer is strongly recommended.
4.4 What power supply design is needed for the 7.5V PA drive?
The PA section requires a dedicated 7-8V supply (7.5V recommended for optimal performance) capable of delivering 1.3A peak current. The control section runs on 4.5-5.5V (5V typical). A common approach is a 12V or 24V industrial rail stepped down via a buck regulator to 7.5V for PA and another to 5V for control. The module will be permanently damaged if the control supply exceeds 6V.
4.5 Is the E21-400G37S certified for FCC/CE compliance in target markets?
The E21-400G37S is a pure-hardware PA component, not a certified end-product transmitter. OEM integrators are responsible for final product compliance testing under FCC Part 15/Part 90, CE RED, KC, NCC or SRRC depending on the deployment region and intended use (ISM vs. licensed). Ebyte provides full technical documentation, RF exposure guidance and reference antenna recommendations (e.g., TX433-XP-200 5dBi) to support customer certification efforts.
