TX915-JK-11B is an industrial-grade 915MHz ISM band rubber antenna featuring a 2.5dBi gain and a low SWR ≤ 1.5, optimized for reliable long-range LoRa and RF communication with a standard SMA-J interface.
| Technical Parameter | Specifications |
|---|---|
| Model Number | TX915-JK-11B |
| Frequency Band | 915 MHz (ISM Band) |
| Antenna Gain | 2.5 dBi |
| Interface Type | SMA-J (SMA Male) |
| Standing Wave Ratio (SWR) | ≤ 1.5 |
| Characteristic Impedance | 50 Ω |
| Antenna Material | Rubber Sleeve |
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Application
Distributed Smart Metering Networks
In urban environments where smart water or gas meters are often housed in metallic or concrete utility boxes, the TX915-JK-11B provides the reliable 915MHz link budget needed to penetrate moderate obstacles. Its omnidirectional pattern ensures consistent data reporting regardless of device orientation.
Industrial Wireless Sensor Nodes
For factory automation involving LoRaWAN or 915MHz proprietary RF sensors, this antenna’s low SWR (≤1.5) minimizes signal reflection back to the transceiver module. This optimizes battery life for remote nodes by ensuring the maximum effective radiated power (ERP) is utilized for each transmission.
Agricultural IoT Gateways
In small-to-medium scale greenhouse monitoring, the TX915-JK-11B serves as a durable and cost-effective communication terminal. The rubberized sleeve protects the internal radiator from high-humidity conditions, providing long-term structural integrity in farming environments.

FAQ
Q: How does the Voltage Standing Wave Ratio (SWR) of ≤1.5 contribute to the link budget of a 915MHz wireless system?
A: An SWR of 1.5 or less indicates that approximately 96 percent of the power delivered by the RF module reaches the antenna radiation element, with less than 4 percent being reflected. In 915MHz systems, minimizing this return loss is critical to prevent the power amplifier from overheating and to ensure the signal maintains enough strength to meet the receiver sensitivity threshold over long distances.
Q: What are the impedance matching implications when connecting the TX915-JK-11B to a PCB with a different characteristic impedance?
A: The TX915-JK-11B is designed with a standard 50-ohm characteristic impedance. If the feeding transmission line on the PCB or the RF module output is not matched to 50 ohms, it creates an impedance discontinuity. This mismatch results in signal reflections and phase distortion, which can significantly degrade the effective 2.5dBi gain and reduce the signal-to-noise ratio (SNR) of the communication link.
Q: Why is the SMA-J interface preferred for industrial RF modules and how does it affect signal loss?
A: The SMA-J interface, or SMA male, is a threaded connector providing high mechanical stability and a wide frequency range up to 18GHz. For a 915MHz antenna like the TX915-JK-11B, the SMA-J interface ensures a low insertion loss connection compared to snap-on connectors. The threaded mechanism provides a consistent electrical contact point, which is essential for maintaining a stable 50-ohm impedance path in environments subject to vibration.