SuperUser Account / Thursday, March 21, 2019

Noise Sources for Testing Interconnects for OTA?

Abstract

Demonstrate the NC1128B broadband noise module used with a spectrum analyzer for verification, calibration and frequency response testing of Over the Air Test Enclosure Systems.

Test your OTA System Frequency Response Fast and Easy

Noisecom NC1000 Broad Band Noise Module

Product Demo:

Demonstrate the NC1128B broadband noise module used with a spectrum analyzer for verification, calibration and frequency response testing of Over the Air Test Enclosure Systems. This methodology is ideal for production test systems using proven technology that mimics transmission of OFDM signals that is fast, cost effective, easy to implement and lowers the cost of production test systems.

Target Users:

Design engineers, production test engineers and systems integrators that develop test stations used for 4G/5G and mmWave devices that require Over the Air Testing for RF performance. VNA’s have long been the standard for testing system performance. Using a noise module with a spectrum analyzer can replace the VNA in test stations.

Test Set-up:

About NC1000 Modules:

The NC1000 Series amplified noise modules produce AWGN as high as +13 dBm, and have bandwidths up to 10 GHz. The high power modules are designed to test noise immunity for Cable TV equipment, secure communication channels, military jamming systems and interconnect testing. The lower power modules, <= 0 dBm, are random jitter sources for many applications including, PCIexpress and 10 GigE. The Bandwidth, output power, and flatness can be modified for specific applications.

Each module contains a hermetically sealed noise diode that has been pre-selected for special performance characteristics the standard module is designed for 50 ohm impedance.

Significant Features of NC1000 series:

Bandwidths up to 10 GHz.
Output power up to +13 dBm.
50 ohm input/output impedance.
Custom solutions available for higher Power and Bandwidths

If there are additional requirements for your noise application, please contact the factory for more information about custom designs.

Determining Interconnect and System Performance of an Over the Air Test Enclosure using the NC1128B:

Our test set-up works using a 10 MHz to 10 GHz module with an output power of 0 dBm. The NC1128B is connected to a spectrum analyzer to obtain a normalized reading. After normalizing the spectrum analyzer the noise source is then connected to a standard gain Vivaldi transmit antenna inside a RF enclosure. The spectrum analyzer is connected to a standard gain Vivaldi receive antenna. The results obtained you can determine path loss and antenna frequency response for the bandwidth of interest. Current test methodologies that have are employed use fast swept CW signals to determine the response of the system. Noise sources transmit an OFDM like signal with a high crest factor and broadband which is important since these are the signals being received and transmitted in modern communication devices for 5G and mmWave signals. With production tests the system can be subject to repeated connections which can degrade connector performance. The noise source can be switched in to determine if the performance has changed without time consuming calibration methods used for VNA.