LimeRFE SDR Platform

The LimeRFE. RF Front End Module for LimeSDR Platforms. A Complete Solution for Custom HAM, Cellular, and Wideband Networks

LimeRFE Software Defined Radio Platform

The LimeRFE. A Software-Definable RF Front End Module for LimeSDR Platforms. A Complete Solution for Custom HAM, Cellular, and Wideband Networks.

The Lime RF Front End (LimeRFE) is an open hardware power amplifier (PA) module with appropriate filtering and support circuitry to augment the LimeSDR, LimeSDR Mini, and LimeNET Micro platforms, providing a complete solution that addresses real life applications ranging from HAM radio to standards-compliant cellular network implementations.

LimeRFE will enhance any LimeSDR based wireless project by providing:

A stronger, clearer signal when transmitting
Less noise when receiving
Improved range for both

Software-Defined Front End

A single LimeRFE covers three very different sets of bands: HAM, cellular, and wideband. The exact band used at any given time is software-selectable. By making the RF front end definable in software, LimeRFE is the next step in the evolution of software-defined radio.

A Note About HF Bands

Depending upon the application and overall system configuration, additional filtering may be required for use with HF bands. In particular, HF is not one, but ten bands starting at 1.6 - 1.8 MHz and moving upward incrementally to 28.0 - 29.7 MHz. On-board filtering will attenuate signals greater than 30 MHz, but not Tx harmonics, or out-of-band Rx signals below this. You may need additional filtering, depending on the environment (if there are nearby HAMs operating on other HF bands, for example) and on whether or not you are using external power amplifiers with integrated filters, antenna tuning units, etc.

Additional Features:

Filtering
Each band has appropriate filtering both for Rx & Tx
Selectable AM/FM notch filter
Fully Open Source Software
Firmware
API support
GUI
LimeSuite integration
Control & Configuration
Programmable via Arduino IDE
Arduino Nano-compatible microcontroller (ATmega328)
FT232RL USB-to-serial converter
Host serial connection via USB mini Type B connector
Power & SWR Meter
1 – 4000 MHz power & SWR meter (external directional coupler required)
Cellular bands Tx power meter (internal coupler)
10-pin Interface to SDR
Power and ground
I2C (SDA and SCL)
2x GPIO connected to on-board microcontroller
4x bi-directional level shifted I/O
1.2 – 5.5 V
Each I/O has a high voltage and power Darlington drive stage for inductive loads (e.g., coaxial relays)
Individually switchable direction (input/output)
Power Supply
Single 12 V supply
Optionally supply microcontroller and Rx channels via USB