Electronic Warfare Antennas: Why Bandwidth Beats Raw Gain

Rarely does an EW system work in one narrow slice of spectrum. Gain often is more important than bandwidth in deciding which antenna to use. A high gain antenna is useful in many setups. But gain alone is not sufficient for a large frequency requirement. A good electronic warfare antenna with wide coverage can reduce the number of antenna designs for a system. However it will not always beat a narrowband high gain antenna. The optimum balance depends upon frequency range, gain, pattern, polarisation and power requirements. This post explains how to weigh those factors.

Why EW Threats Spread Across Many Bands

Various RF systems use different portions of the spectrum. Some signals are tight. Others are spread out over a wide range. To operate in such an environment, an EW system needs antennas that can cover the environment.

A narrowband antenna can be tuned very closely. Designers can drive gain and pattern control for a band. A broader design must keep several parameters constant over its range. Pattern and gain and impedance , all change with frequency . So something's got to break. That trade off is at the heart of the bandwidth vs. gain debate.

What Wide Bandwidth Saves on a Platform

Imagine a platform with less space. Each additional antenna requires cable runs and mounting points. It also requires integration work and testing. Broadband antennas can reduce the number of antenna types required for the system. This could translate to fewer antennas per platform and a simpler install.

That only works if the antenna meets the real requirement. In one band, a wideband element might not match the gain or pattern of a narrowband element. What one antenna can replace a number of antennas depends on the frequency range, gain, pattern and polarisation the system requires.

And watch out for the ultra wideband coverage. Wideband is not the full story. It is a very large fractional bandwidth. The antenna response should be shown in the datasheet over that whole range. “Look at the numbers before you choose the label.

Where High Gain Still Matters

The profit is still there. To point energy where you need it, a directional setup requires gain. Link gain is part of the link budget. It also has to do with antenna efficiency and the radiation pattern. Higher gain generally results in a narrower beamwidth. That works for directional stuff. You get into the problem of wide angular coverage.

The gain also changes with frequency. The figure at some point may not be true for the band. So a broadband antenna may have less peak gain than a tuned narrowband one. That’s the cost of more coverage.

When the first requirement is wide frequency coverage, bandwidth may be more valuable than gain. If directional performance and signal level is paramount then high gain is still important.

How to Judge an EW Antenna Datasheet

Don’t judge an antenna on a single headline number. Check these items after reading the entire datasheet.

• Frequency range

• Gain across the band

• VSWR across the band

• Polarization

• Radiation pattern

• Impedance

• Connector type

• Power handling

• Physical dimensions

• Environmental specifications

Why Choose Antenna Experts?

Antenna Experts is an antenna manufacturing company in India with expertise in designing and supplying antennas for various technical requirements. Our portfolio includes Electronic Warfare Antennas, Yagi antennas, omnidirectional antennas, horn antennas, radar antennas and other RF antenna solutions. The company serves buyers who want antennas for communication, defence, testing, radar, surveillance and other RF applications. Our technical team is aware of the key specifications that buyers need to compare such as frequency range, gain, VSWR, polarisation and antenna type. Antenna Experts share the product specifications to help engineers, system integrators and procurement teams to select an antenna for their application and technical requirements.

FAQs

1. Why do electronic warfare antennas need wide bandwidth?

EW systems can operate in a number of frequency bands. A wider bandwidth means one antenna design can cover more of that spectrum. That can cut down the number of antenna types a platform needs. But there are design compromises. Adding more bandwidth doesn’t necessarily improve the gain or pattern performance.

1. Is a high gain antenna useful for jamming?

Gain is a measure of how well an antenna focuses RF energy . It matters in many designs. But selection depends also on frequency coverage and beamwidth. The polarisation and the power handling also matter. This answer is general engineering information only This is not guidance for a particular system or operation.

1. What VSWR is acceptable for a broadband EW antenna?

There is no one number that fits all. The allowable VSWR depends on the system and the frequency band. It also depends on the requirement of the transmission. Buyers should review the manufacturer’s VSWR curve over the entire operating band. A weak match at the band edges can be hidden by one figure.

About the Author

Gurleen Neyar is the Marketing Manager at Antenna Experts. Gurleen writes on antennas and technical products. Gurleen also assists in the company’s marketing. We are dedicated to clear technical product information. This way shoppers can compare options and get key specs before they purchase.