This version (18 May 2023 17:15) was approved by Brandon Bushey.The Previously approved version (18 May 2023 17:13) is available.Diff

EVAL-CN0521-EBZ User Guide


The EVAL-CN0521-EBZ is a USB-powered, RF low noise amplifier (LNA) that is optimized for receiving signal chains in the 2.4 GHz ISM band. Using two HMC639 amplifiers cascaded together, the design provides a gain of 21 dB and return losses of more than 10 dB throughout its RF band of operation.

The board includes a high speed overpower cutoff that protects sensitive downstream equipment connected to the receiver system. The receiver system also automatically turns back on when the RF power level drops within the acceptable range.

Designed to be used with the ADALM-PLUTO, the EVAL-CN0521-EBZ features a small form factor, with dimensions of 25.4 mm × 49.6 mm x 1.5748 mm (PCB only). The RF input and output are designed with a 50 Ω impedance, enabling direct connection between the circuit and standard 50 Ω systems.

A micro-USB connector is used for the input power, allowing the evaluation board to use most +5 V wall wart power supplies available in the market.

 Figure 1. EVAL-CN0521-EBZ Reference Design Board
The EVAL-CN0521-EBZ features the HMC639, which is a GaAs, pHEMT, high linearity, low noise amplifier operating between 0.2 GHz to 4 GHz for various applications such as fixed-wireless, cellular, and CATV. This low noise RF amplifier does not require any external matching circuitry to operate.
 Figure 2. EVAL-CN0521-EBZ Simplified Block Diagram


Figure 3. CN0521 Primary Side

 Figure 4. CN0521 Secondary Side

SMA Connectors

The SMA connectors are used for the RF input and output connections.

RF Port Reference Designator Description
RF Input ​​(SMA male connector) J1 Connect to a radio or piece of RF equipment ​
RF Output ​​(SMA female ​connector) J2 Connect to an antenna ​

LED Indicators

The reference design uses two LEDs to indicate its current status:

RF Port Reference Designator Description
Green ​LED (DS2) Indicates that power is present on the board
Red ​LED (DS1) ​ ​Indicates when an overtemperature event occurs ​​

This table shows the board status when the various LEDs are ON/OFF.

Green LED Red LED Board Status
OFF OFF No Power
ON Off Normal RF Operation
ON ON Overpower Event (RF Output Attenuated)

Power Supply Connector

  • P1 is the micro-USB port used to provide +5 V power to the board.

Getting Started

Required Equipment



For the step-by-step procedure on how to update the Pluto Firmware, you can use this user guide link.

The latest firmware version for the ADALM-PLUTO can be found here:


ADALM-PLUTO Preparation

Follow the step-by-step process on how to configure the ADALM-PLUTO for proper operation by referring to this link.

Test Setup

Normal Operation

Figure 5. EVAL-CN0521-EBZ Test Setup

  1. Connect directly the Rx port of ADALM-PLUTO to J2 of the EVAL-CN0521-EBZ
  2. Connect the Tx port of the ADALM-PLUTO to J1 of the EVAL-CN0521-EBZ using a male-to-male SMA cable.
  3. Connect P1 (micro-USB) connector of the EVAL-CN0521-EBZ into a PC USB port or 5 V USB charger.
  4. Connect the micro-USB to USB cable to a PC/laptop and the other end to the ADALM-PLUTO data port.
  5. The DS2 LED of EVAL-CN0521-EBZ will automatically turn on, indicating the board is powered on and is in operation.

IIO Oscilloscope

Make sure to download/update to the latest version of IIO Oscilloscope found on this link
  • Once done with the installation or an update of the latest IIO Oscilloscope, open the application. The user needs to supply a URI, which will be used in the context creation of the IIO Oscilloscope. The instructions can be seen in the previous section.
  • Press refresh to display available IIO devices. Once the ADALM-PLUTO appeared, press connect.

Figure 6. IIO Oscilloscope Configuration

  • On the AD936x tab, refer to this link for the proper configuration of the AD936x.
  • Using the capture window, you can see the RF output of the EVAL-CN0521-EBZ in the frequency domain.

Figure 7. CN0521 RF Output

Schematic, PCB Layout, Bill of Materials

EVAL-CN0521-EBZ Design & Integration Files

  • Schematics
  • PCB Layout
  • Bill of Materials
  • Allegro Project


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resources/eval/user-guides/circuits-from-the-lab/cn0521.txt · Last modified: 18 May 2023 17:15 by Brandon Bushey