Marconi experimented with shortwave radio technology and demonstrated its potential for long-distance communication. He developed directional shortwave antennas, which significantly improved signal strength and reduced interference.

Marconi conducted research on microwave communication, exploring the possibilities of using shorter wavelengths for higher-bandwidth transmission. While he did not live to see the full development of microwave technology, his early experiments laid the groundwork for future advancements.

Marconi continued to focus on improving maritime communication systems, developing more reliable and efficient equipment for ships and coastal stations. His contributions significantly enhanced safety and communication at sea.