02 | Keysight | Surveying the Best Ways to Test Antennas and Antenna Arrays - Application Note

As derived in Part 1 of this series, the radar range equation captures the essential

variables that define the maximum distance at which a given radar system can detect

objects of interest. Because the variables relate directly to the major sections of the

system block diagram, they provide a powerful framework for the essential process of

understanding, characterizing and verifying the actual performance of any radar system.

Parts 2 and 3 of this series defined the pulsed radar signal, described ways to measure

the power in those signals, and presented readily available ways to measure the

essential characteristics of pulsed signals: frequency, timing, power and spectrum. Part

4 examined the use of vector signal analysis (VSA) and wideband instruments—signal

analyzers and oscilloscopes—to measure frequency, phase, and more, in today’s

increasingly complex radar signals. Part 5 provided a closer look at the testing, analysis

and optimization of the components and subassemblies used in today’s radar systems.

In our ongoing discussion of practical test methods, we’ll now take a closer look at the

testing of antennas and antenna arrays. This topic spans a variety of test setups and test

methods: far-field and near-field test ranges; multi-aperture and phased-array radar

systems; and radar cross-section (RCS) measurements.

Across these requirements, narrowband or wideband measurement techniques may

provide the desired results. Vector network analyzers can perform essential narrowband

measurements of magnitude (gain), phase and impedance, and they provide the

sensitivity needed to obtain excellent results when dealing with extremely small

signals in RCS testing. For wideband measurements, modular AXIe digitizers are the

foundation of a flexible reference solution designed to address multi-channel antenna

characterization.

The radar series

This application note is the sixth in a

series that delves into radar systems

and the associated measurement

challenges and solutions. Across the

series, our goal is to provide a mix of

timeless fundamentals and emerging

ideas.

In each note, many of the sidebars

highlight solutions—hardware and

software—that include future-ready

capabilities that can track along with

the continuing evolution of radar

systems.

Whether you read one, some or all of

the notes in the series, we hope you

find material—timeless or timely—that

is useful in your day-to-day work, be

on it new designs or system upgrades.

1. The appendix at the end of this application

note presents the range equation and the

system block diagram.