The Radar Warning Receiver (RWR) on the F-18 Hornet is a critical electronic warfare system designed to detect, identify, and warn pilots about radar emissions from potential threats such as enemy aircraft, surface-to-air missiles, and ground-based radar systems. Understanding the frequencies that the RWR detects helps in grasping how it provides situational awareness and protection.
Frequency Bands Detected by the F-18 RWR
The RWR primarily scans a broad range of radar frequencies to cover the common radar threat bands. These include the following radar frequency bands (defined by NATO letter designations):
- Band A / VHF (Very High Frequency): 30 - 300 MHz
This band is less common for targeting radars but can detect early warning radars which operate at lower frequencies. - Band B / UHF (Ultra High Frequency): 300 MHz - 1 GHz
Detects longer-range search and surveillance radars. - Band C: 1 - 2 GHz
Includes some tracking and fire control radars. - Band D: 2 - 3 GHz
Covers some early missile guidance radars. - Band E / S-band: 2 - 4 GHz
Widely used by tracking radars and some missile guidance systems. - Band F / X-band: 8 - 12 GHz
Commonly used by fire control radars, missile seekers, and targeting radars. This band is critical for RWR as it indicates precision threat radars. - Band G / Ku-band: 12 - 18 GHz
Less commonly used but can include radar altimeters and some missile seekers.
Function of Frequency Detection in RWR
The F-18 RWR uses a wideband antenna system and signal processing to scan these frequency bands continuously. When it detects a radar emission within these bands, it analyzes the signal's frequency, pulse repetition frequency (PRF), pulse width, and other characteristics to classify the threat type (e.g., search radar, tracking radar, missile guidance radar).
By knowing the frequency, the RWR can provide the pilot with:
- Threat identification icons indicating the type of radar threat
- Directional cues to locate the source of the radar
- Priority based on threat severity and proximity
Summary
The F-18 RWR detects a broad spectrum of radar frequencies, spanning from VHF/UHF bands up to Ku-band frequencies, covering the full gamut of radar systems used to detect, track, and engage the aircraft. This allows the F-18 pilot to maintain awareness of enemy radar activities and take appropriate countermeasures.