Why 2.4 GHz Is No Longer 'Short Range Only'
Across the broad landscape of IoT, the 2.4 GHz band is the core choice for smart homes, wearables and wireless remote control thanks to its global license-free status, high data rates and rich ecosystem compatibility. And with spread-spectrum technologies like LoRa entering the band, 2.4 GHz has shed its old 'short-range' label - finally combining long range, low power and high throughput. EBYTE's E28-2G4M series, built on Semtech's flagship SX1281 RF chip, offers a complete product gradient from a 12 dBm economy model to a 27 dBm high-power flagship. This article breaks down six key models: E28-2G4M12S, E28-2G4M12SX, E28-2G4M20S, E28-2G4M20SX, E28-2G4M27S and E28-2G4M27SX.
Product Overview
The E28-2G4M series is a family of self-developed ultra-compact SMD RF transceiver modules for the 2.4 GHz band, built on the Semtech SX1281 chip. The SX1281 supports LoRa, FLRC and GFSK modulations, is compatible with Bluetooth protocols, and integrates RSSI signal-strength indication plus Time-of-Flight (ToF) ranging. All models use a 52 MHz industrial-grade, high-precision, low-drift active crystal oscillator for industrial robustness and stability.
The series covers six mainstream models: E28-2G4M12S / 12SX - economy, 12 dBm output, no PA/LNA, compact footprints (24 x 14 mm / 17.8 x 15 mm). E28-2G4M20S / 20SX - medium power, 100 mW (20 dBm) with built-in PA + LNA for a major stability lift (15 x 26.5 mm / 15 x 20 mm). E28-2G4M27S / 27SX - high-power flagship, 500 mW (27 dBm) with PA + LNA for long-range backbones and complex environments (15 x 26.5 mm / 15 x 20 mm).
Key Features and Model Comparison
Multiple modulations, excellent performance: LoRa, FLRC and GFSK are all supported - LoRa and FLRC significantly extend transmission distance, while Bluetooth-protocol compatibility lets the modules plug seamlessly into the BLE ecosystem.
Long range with strong interference immunity: 2.4 GHz LoRa spread-spectrum technology pushes the E28-2G4M27S/SX to a maximum 8 km under ideal conditions, with blocking characteristics that outperform traditional FSK and GFSK schemes.
Multiple power grades: 12 dBm, 20 dBm and 27 dBm levels are available, each software-adjustable in multiple steps so you can trade power against range freely.
Built-in PA + LNA, multiplied stability: the M20/M27 families integrate a power amplifier and low-noise amplifier inside the module, lifting output to 100 mW / 500 mW while further optimizing receive sensitivity - overall communication stability is dramatically better than products without PA/LNA.
Ranging function, expanding the application boundary: the SX1281's Time-of-Flight engine turns these communication modules into platforms for wireless distance measurement, positioning and tracking.
Complete software compatibility: drive the module exactly like a bare SX1281 per its datasheet, with EBYTE's SDK and reference demos cutting development effort dramatically.
Feature | E28-2G4M12S | E28-2G4M12SX | E28-2G4M20S | E28-2G4M20SX | E28-2G4M27S | E28-2G4M27SX |
|---|---|---|---|---|---|---|
Chipset | Semtech SX1281 | Semtech SX1281 | Semtech SX1281 | Semtech SX1281 | Semtech SX1281 | Semtech SX1281 |
Frequency Band | 2.4 GHz | 2.4 GHz | 2.4 GHz | 2.4 GHz | 2.4 GHz | 2.4 GHz |
Tx Power | 12 dBm | 12 dBm | 20 dBm (100 mW) | 20 dBm (100 mW) | 27 dBm (500 mW) | 27 dBm (500 mW) |
Reference Range | 3 km | 3 km | 6 km | 6 km | 8 km | 8 km |
Built-in PA + LNA | No | No | Yes | Yes | Yes | Yes |
Dimensions (mm) | 24 x 14 | 17.8 x 15 | 15 x 26.5 | 15 x 20 | 15 x 26.5 | 15 x 20 |
Antenna | PCB onboard / IPEX | IPEX / stamp holes | PCB onboard | IPEX / stamp holes | PCB onboard + IPEX | IPEX / stamp holes |
Interface | SPI | SPI | SPI | SPI | SPI | SPI |
Supply Voltage | 1.8 - 3.6 V | 1.8 - 3.6 V | 1.8 - 3.6 V | 1.8 - 3.6 V | 2.5 - 3.6 V | 2.5 - 3.6 V |
Typical Use | Economy portable terminals | Ultra-compact portable devices | Medium/long-range industrial links | Medium/long-range compact devices | Long-range backbone, gateways | Long-range compact gateways |
In short: the M12/M12SX are economy entry choices for cost-sensitive portable terminals and smart-home devices - the SX variant uses a tighter 17.8 x 15 mm footprint with only IPEX/stamp-hole antenna options. The M20 and M27 families both add PA + LNA for a major stability lift: the M20 series' 100 mW covers medium/long-range scenarios, while the M27 series' 500 mW delivers the strongest performance for backbone networks and difficult terrain.
Technical Specifications
Typical values across the E28-2G4M series: chipset Semtech SX1281 (original imported); modulation LoRa / FLRC / GFSK (Bluetooth-protocol compatible); operating band 2400 - 2500 MHz (ISM 2.4 GHz); Tx power 12 / 20 / 27 dBm, software-adjustable in multiple steps; Rx sensitivity -134 to -137 dBm depending on modulation and data rate; interface SPI; crystal 52 MHz industrial-grade high-precision low-drift active oscillator; supply voltage 1.8 - 3.6 V (M12/M20) and 2.5 - 3.6 V (M27); operating temperature -40 C to +85 C (industrial grade); package SMD with 1.27 mm pin pitch; signature features: RSSI indication and Time-of-Flight ranging.
Typical Applications
Smart home and security systems: wireless connectivity and control for smart appliances, smart locks, environmental sensors and alarm panels.
Positioning, tracking and wireless ranging: indoor positioning, asset tracking and distance measurement powered by the SX1281's Time-of-Flight engine.
Wearables and health management: low-power wireless data backhaul for smart bands and health-monitoring patches.
Industrial sensors and data acquisition: equipment condition monitoring, data acquisition and remote control on the factory floor - the M20/M27 families are especially suited to electromagnetically harsh industrial environments.
Wireless remote control and drones: a high-reliability, low-latency link between remote controllers and UAVs.
Medium/long-range wireless communication: the core module inside IoT gateways and data concentrators, building high-speed 2.4 GHz LoRa networks.
EBYTE (Chengdu Ebyte Electronic Technology Co., Ltd.) is a leading Chinese supplier of IoT communication and wireless module solutions, headquartered in Chengdu Hi-Tech Zone with a strong in-house R&D team. Its portfolio spans LoRa, Sub-1G, WiFi, Bluetooth, NearLink, ZigBee, GNSS positioning, industrial power and embedded industrial computers. Guided by the philosophy of professionalism, innovation and service, EBYTE delivers high-quality, high-reliability wireless modules and complete solutions to customers worldwide. Disclaimer: this product must not be used in military or life-safety-related scenarios; users bear responsibility for strict compliance with the hardware design and software configuration requirements of the manual.
FAQ
Q: How is 2.4GHz LoRa different from Sub-1G LoRa?
A: 2.4 GHz LoRa (SX1281) offers much higher data rates (FLRC up to 1.3 Mbps class), global license-free spectrum and ToF ranging, at shorter range than Sub-1G. Sub-1G (SX1268) wins extreme range and penetration. Choose 2.4 GHz for speed, ranging and worldwide deployment; Sub-1G for kilometer-scale telemetry.
Q: What does the SX suffix mean on E28-2G4M models?
A: SX models (M12SX/M20SX/M27SX) drop the PCB onboard antenna and provide only IPEX / stamp-hole external antenna interfaces in a more compact footprint (e.g. 17.8 x 15 mm vs 24 x 14 mm), letting you optimize the antenna design for your enclosure.
Q: Can the E28-2G4M series be used for positioning?
A: Yes. The SX1281 integrates a Time-of-Flight (ToF) ranging engine, so besides communication the modules enable indoor positioning, asset tracking and wireless distance measurement applications.