What is an EMC Antenna? 

EMC Antennas are application-specific antennas used for emissions and immunity measurements during EMC testing. These antennas generally excel in stringent environments, withstanding daily handling and exposure to varying weather conditions. These are usually deployed in anechoic chambers or open-area test sites. Their frequency bandwidth is a critical parameter in categorizing them for different testing and measurement scenarios. Alignments go with EMC Standards as well, to fulfill essential requirements. The other parameters to consider are gain, VSWR, antenna factor, etc.

Common types and their applications in EMC testing:

1. Log-Periodic Antennas: Log Periodic Antennas are characterized by triangular/trapezoidal elements arranged on a boom. The smaller elements are designed to receive higher frequencies while the larger elements receive lower frequencies. These antennas are commonly used for radiated emissions/immunity testing from 300MHz to 1GHz. These antennas have a high gain.

Log-periodic Antenna

2. Biconical Antennas: These are conical-shaped, two-element broadband antennas used for radiated emissions/immunity testing from 25 MHz to 200 or 300 MHz. Their symmetric design helps in achieving uniform radiation patterns and accurate measurements in testing environments. 

Biconical Antenna

3. Dipole Antennas: These inexpensive antennas are typically used for radiated immunity testing. These do not have a broad bandwidth but are very directional. These antennas are designed to radiate or receive electromagnetic radio waves in a specific direction, perpendicular to the axis formed by the two elements or poles.

Dipole Antenna

4. Horn Antennas: These antennas are designed to perform radiated emissions/immunity testing beyond 700MHz. These generally have a high gain and low VSWR. They may be categorized into 

Standard Gain Horn Antenna: These are broadband antennas having high gain. Besides EMC testing, these antennas are used in satellite communication systems to transmit and receive radio waves between satellites and ground stations. 

Standard Horn Antenna

Ridged Waveguide Horn Antennas: These antennas consist of a waveguide that is flared out at the end to form a horn shape. Its ridges help improve its overall broadband performance. These can operate over a wide frequency range, typically from 30 MHz to 18 GHz or higher. Broadband Ridged Waveguide Horn Antennas find their use in satellite communications, antenna pattern measurements, etc., other than EMC testing.

Ridged Horn Antenna

5. Loop antennas: These compact and cost-effective antennas measure electric fields from 20 Hz to 30 MHz. They are not as directional as other antennas, but they are susceptible to electric fields. These antennas can effectively reduce interference and noise which results in high-quality reception. They can be tuned to certain frequencies if required, by the use of capacitors or by adjusting the number of turns in the loop.

Loop Antenna

6. Active-Loop Antennas: These antennas are used for radiated emissions testing from 9 kHz to 30 MHz. They use a Low Noise Amplifier(LNA) for their operation. These can be customized to include directional properties.

Active Loop Antenna

7. Bilog/Bicolog Antennas: These are specialized omnidirectional wideband antennas designed to conduct emissions and immunity testing up to 2GHz(may even extend to 3 or 6GHz or more). 

Bilog/Bicolog Antenna

8. Conical Log-Spiral Antennas: These antennas can operate over a wide frequency range, typically from 30 MHz to 18 GHz or higher, and are specifically used for radiated emissions/immunity testing. These consist of a spiral-shaped radiating element that is typically printed or etched on a dielectric substrate. 

Spiral Antenna

 9. Rod/Monopole Antennas: These antennas have a single element which is typically a rod with directional properties. These antennas are commonly used for AM and FM radio broadcasting, mobile phone communication and in wireless LAN (Wi-Fi) devices, RF spectrum analyzers other than EMC Testing.

Monopole Antenna

EMC Directory has listed EMC Antennas from the leading manufacturers. Click here to view.