AESA vs. PESA Radar: Key Differences Explained

This article breaks down the distinctions between AESA (Active Electronically Scanned Array) radar and PESA (Passive Electronically Scanned Array) radar. Let’s dive in!

AESA stands for Active Electronically Scanned Array, while PESA stands for Passive Electronically Scanned Array.

PESA Radar Explained

PESA Radar Working

PESA radar uses a common, shared RF source where the signal is modified using digitally controlled phase shifter modules. Here’s a look at the key features:

• Single Transmitter/Receiver: As shown in the image above, it employs a single transmitter/receiver module.
• Electronic Beam Steering: PESA radar generates a beam of radio waves that can be steered electronically in various directions.
• Single Point of Connection: Antenna elements are interfaced with a single transmitter/receiver.
• Jamming Vulnerability: Due to its use of a single frequency, it’s more susceptible to jamming by enemy RF jammers.
• Slower Scan Rate: PESA radar has a slower scan rate and typically tracks only a single target or handles a single task at a time.

The fundamental difference between PESA and AESA lies in how the antenna elements are managed. PESA uses a single transmitter/receiver for all elements, while AESA utilizes separate transmit/receive modules for each.

AESA Radar Explained

AESA Radar working

AESA radar uses an electronically controlled array antenna where the radio wave beam can be electronically steered, pointing in different directions without physically moving the antenna. It’s considered a more advanced iteration of PESA radar.

Here are the key features of AESA radar:

• Multiple Transmitter/Receiver Modules: It utilizes multiple transmitter/receiver modules.
• Array Antenna Interface: These modules are interfaced with multiple antenna elements forming an array antenna.
• Multiple Beams & Frequencies: AESA radar can generate multiple beams at different radio frequencies simultaneously.
• Jamming Resistance: Thanks to its ability to generate multiple frequencies over a wide range, it’s less likely to be jammed.
• Fast Scan Rate & Multi-Target Tracking: AESA radar has fast scan rates and can track multiple targets or handle multiple tasks concurrently.

For a deeper understanding, refer to the AESA Radar block diagram.

Similarities Between Modern PESA and AESA Radars

Despite their differences, modern PESA and AESA radars share some common traits:

• Pulse Radars: Both are generally pulse radars.
• Frequency Agility: Both can be frequency agile and frequency hopped at different frequencies at different times.
• Bandwidth Modes: Both can operate in narrow band and wide band modes.
• Versatility: Both can be used for ECM (Electronic Countermeasures), passive scanning, and beamforming.