The EA-6B became the sole U.S. tactical electronic warfare aircraft after the retirement of the EF-111. As the Prowlers retire, the Navy and Air Force electronic warfare will again diverge. Where the Navy uses Growlers, the Air Force intends to create modified EB-52 and EB-1 bombers for standoff jamming, and carry out the close-in jamming mission with unmanned aerial vehicles (UAV) such as variants of the MQ-4 Global Hawk or MQ-1 Predator. The AN/ALQ-214 integrated electronic countermeasures suite on the B-1 and Super Hornet always will have warning receivers, but, if flying with a Growler, mission planners may choose to omit the modular jammers from the attack aircraft, leaving the jamming mission to the pure electronic warfare Growlers.
While there will be much more computing power aboard this aircraft, it is still replacing an aircraft with a pilot and 3 electronic warfare officers, with an aircraft with a pilot and a single electronic warfare officer. It also has less room for computers, elecronics, and antennas.  While computers and electronics continue the miniaturization trend, there are often physical limits to the size of antennas. The Super Hornet base AN/APG-79 active electrically scanned array (AESA) radar, which does offer alternative ways to carry out both receiving and transmitting antenna functions.
Since the EF-18 has the performance of the F-18 fighters, it is not restricted to standoff jamming as was the Prowler, but can escort the strike aircraft into the target area.
Growler functionality adds to that of the Super Hornet
Super Hornets of the Block 30 version also have AN/ALQ-218(V)2 tactical jamming receivers and other equipment that can be used for dedicated electronic warfare. The basic Super Hornets have standard capability to fire not only AGM-88 HARM anti-radiation missiles, but also AIM-120 AMRAAM air-to-air missiles and AGM-154 Joint Standoff Weapon (JSOW) missiles carrying cluster submunition warheads.
Adding the Growler functionality increases the weight of the two-seat F-18F by about 1,400 pounds but also 1.5 million lines of software code to a two-seat Super Hornet. 
Visually, the Growler differs from the Super Hornet in that the wingtip mounting points, used for air-to-air missiles on the Super Hornet, will usually carry wideband receiver pods.
Human factors improvements of the Super Hornet base should contribute to reducing workload and allowing a smaller crew. These include helmet-mounted cueing system (HMCS) and heads-up display (HUD), an improved crew station with multifunction displays; Tactical Aircraft Moving Map Capability (TAMMAC); and HOTAS Hands-On Throttle and Stick control.
The EA-18G also introduces an Interference Cancellation System (INCANS)to enhance the situational awareness of the crew during the AEA mission.
Electronic warfare equipment
A Prowler could carry up to 5 AN/ALQ-99 jammer pods, while the Growler, in its Block 1 configuration, can have three plus a AN/ALQ-227 communications countermeasures system. Block 2, however, integrates electronic warfare with the AESA radar, which can jam as well as track and receive.  All the receivers and direction finders can provide electronic intelligence.
New equipment, compared to the Prowler, includes an AN/ALQ-227 Communications Countermeasures Set (CCS) in place of the Prowler’s BAE USQ-113 CCS. A CCS locates, records, plays back (for deception) and, through an AN/ALQ-99 pod, jams more complex waveforms over a broader frequency range. This new device replaces four on the Prowler. 
Another Block 2 enhancement is the AN/ALQ-218(V)2 upgrade of the Improved Capabilities (ICAP) III system passive signal analyzer on the Prowler. Prowler aircraft. It has antennas on the port and starboard sides of the nose, the engine bays, in the wingtip pods and to the aft of the cockpit, providing 360° azimuthal cover. This system detects, locates, and identifies threats. 
- "EA-18G Airborne Electronic Attack Aircraft F/A-18G "Growler"", Globalsecurity.com
- Colucci, Frank (1 March 2008), "Teeth of the Growler", Avionics Magazine