Multichannel Frequency Synthesizer ATE System

The Challenge

Design, develop, and deploy a flexible and precise automated test equipment (ATE) system for a 6-channel tunable and a 4-channel fixed-frequency synthesizer.

The Solution

Using the LabVIEW graphical system design environment with NI RF hardware to develop a flexible and high-speed ATE system that uses the latest technology and saves time and money.

Technology

• NI PXIe-6537 module for 2-channel TTL pulse generator

• NI PXIe-5162 4-channel oscilloscope

• NI PXIe-2543 module

• PXI-2596 module

• NI PXIe-5652 signal generator to test path calibration

• NI PXIe-5450 signal generator for DUT reference frequency (75 MHz)

• PXI-5691 amplifier for splitter loss compensation

• USB-5680 power meter

• NI PXIe-5663 vector signal analyzer (external LO mode) with QuickSyn

Problem Background and Solution

Our customer designs and manufactures high-performance RF signal sources using frequency synthesis techniques for generating an output frequency, which support a wide range of commercial and industrial RF applications. The customer’s device under test (DUT) superficial testing includes 10 measurements at three frequencies (the start, middle, and end frequency of the synthesizer’s tunable bandwidth). This requires 5–8 hours of time from a professional engineer. The DUT also supports pulse modulation through two input TTL channels.

Individual test design, manual assembly, system calibration, and reporting are the most time-consuming procedures for DUT engineers. Our company has developed a 12-channel frequency synthesizer ATE system with testing capabilities from 10 MHz to 6.6 GHz.

List of measurements includes:

• Output signal frequency range

• Maximum frequency deviation from nominal value

• Output power

• Frequency setting time

• Amplitude modulation depth

• Amplitude-frequency response (flatness) in tunable bandwidth

• Delay instability of an output RF pulse versus input synchronization pulse

• Rising\falling edge delays of an RF pulse versus input IF pulse rising\falling edges

• Radio pulse rise and fall time

• RF pulse amplitude flatness

• Radio pulse amplitude instabilities generated in .5 s phase noise, offsets from the carrier 1 kHz, 5 MHz

• Output signal amplitude noise

• Spurious emissions, harmonics, and subharmonic

The customer’s synthesizer phase noise was sufficiently low at 120 dB c\Hz in 800 MHz. With our current configuration, users can achieve residual FM specifications, low nonharmonic, and excellent SSB phase noise up to -135 db c\Hz (800 MHz, 10 kHz offset).

Synthesizer phase noise I.

Synthesizer phase noise II.

Conclusion

It took our team 4.5 months to organize the project, design the ATE system architecture, develop, program, and install the system at the customer site. Using our ATE system, the customer can decrease the testing time by up to 30X and measure 25 parameters for 10-channel and 400 frequency steps (10 MHz to 6.6 GHz).

Original Authors:

Davit Zargaryan, 10X Engineering LLC

Edited by Cyth Systems