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Getting Started: XB300 Amplifier Board

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Brian Glod edited this page Aug 27, 2018 · 5 revisions

Table of Contents

Overview

The Nuand XB‑300 is an amplifier expansion card that greatly increases the range of the bladeRF. On the receive side, the XB‑300 features a low-noise amplifier (LNA) and a combiner for antenna diversity. The transmit side features a Power Amplifier (PA), TRX switch, and a highly accurate ADC for measuring output power of the PA. The schematic for the XB‑300 is available here.

The TSS‑53LNB wideband (0.5-5 GHz) LNA found in the RX path provides a low noise figure and a maximum gain of 20 dB.

The SE2623L PA in the TX path offers up to 33 dBm of gain in the 2.4 GHz ISM band. It features an integrated temperature-compensated power detector.

The XB-300 ships in a configuration designed for separate RX and TX paths. Thus, if you are using an XB-300 in its "out of the box" state, follow the RX and TX instructions below.

The population of resistors R8, R10, and R23 select the input to the RX LNA. Users may adjust the resistor options to instead use a single antenna and the on-board TRX switch, or add an additional RX antenna input to a combiner for diversity.

Hardware Configuration

RX

  1. Connect the bladeRF RX SMA connector (J53) to the XB-300 RXIF SMA (J7) with an SMA cable.
  2. Connect a cable or antenna to the XB-300 RX ANT SMA connector (J5).

TX

  1. Connect the bladeRF TX SMA connector (J54) to the XB-300 TXIF SMA (J4) with an SMA cable.
  2. Connect a cable or antenna to the XB-300 TRX ANT SMA connector (J3).

TRX

Follow the above instructions for TX

Example Connection

The following demonstrates the SMA and antenna connections when using one RX antenna and one TX antenna. This is the default, as-shipped, configuration.

Usage

The general steps for using the XB-300 are as follows:

  1. Enable the board. This configures and initializes the expansion port GPIOs.
  2. Enable the LNA and/or PA.

libbladeRF

Enable the XB-300: 

int status = bladerf_expansion_attach(device_handle, BLADERF_XB_300);

Enable the the LNA or PA: 

bladerf_xb300_amplifier amp = BLADERF_XB300_AMP_LNA; /* Or BLADERF_XB300_AMP_PA */
bool enable = true;
int status = bladerf_xb300_set_amplifier_enable(device_handle, amp, enable);

For users that have performed the TRX resistor modification, the TRX switch can be configured as follows: 

bladerf_xb300_trx trx = BLADERF_XB300_TRX_RX; /* Or BLADERF_XB300_TRX_TX */
int status = bladerf_xb300_set_trx(state->dev, trx);

bladeRF-cli

The below snippet lists the commands needed to enable the XB-300, turn on the TX PA, and to turn on the RX LNA: 

bladeRF> xb 300 enable

  Enabling XB-300 Amplifier board
  XB-300 Amplifier board successfully enabled

bladeRF> xb 300 pa on

  PA: Enabled

bladeRF> xb 300 lna on

  LNA: Enabled

For users that have performed the TRX resistor modification, the TRX switch can be configure as followed: 

# Set switch to TX
bladeRF> xb 300 trx tx

# Set switch to RX
bladeRF> xb 300 trx rx

Recommendations

An external DC power supply is highly recommended when using the XB-300. See this page for instructions on how to power the bladeRF from an external DC supply instead of the USB connection.

When using the TX PA, additional external filtering for the band/channel of interest is also highly recommended. The connectorized filters provided by Mini-Circuits are a great option, but there are many other vendors and options available.

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