Can SDR Transmit?

Yes, software-defined radio (SDR) can transmit as well as receive signals, provided it is designed with the capability to do so.

SDRs are versatile tools that use software to perform many functions that were traditionally done with hardware, such as modulating and demodulating radio signals, and filtering. This flexibility allows SDRs to handle a wide range of frequencies and modes, including transmission modes.

However, it’s important to note the following:

Transmitter Hardware

Not all SDRs have built-in transmitters. Some (like the RTL-SDR) are designed only for receiving signals. Those SDRs that can transmit will have specific hardware enabling them to generate and send out radio frequency signals.

Examples of such SDRs are HackRF and Pluto SDR.

We covered SDR transmitters in this post.

Nooelec HackRF One Software Defined Radio, ANT500 & SMA Adapter Bundle for HF, VHF & UHF. Includes SDR with 1MHz-6GHz Frequency Range & 20MHz Bandwidth, ANT-500, and 4 SMA Adapters

Licensing Requirements

Transmitting with an SDR, like with any radio equipment, is subject to regulatory approval. In many countries, transmitting without the proper license, especially on frequencies that require licensing, is illegal. Users must ensure they are compliant with local regulations regarding radio transmissions.

Capabilities and Limitations

The frequency range and power of the transmission depend on the specific SDR hardware. Some might be capable of very low power transmission, suitable only for experimental or amateur use, while others can be quite powerful.


SDRs are used in various applications including amateur radio, commercial radio, military and research purposes due to their adaptability and the broad range of frequencies they can handle. While most SDRs are capable of receiving signals only, there are many that can transmit as well.

Portapack H2, 1MHz-6GHz Radios Transceiver Capture Replay for Communication