PHD Discussions Logo

Ask, Learn and Accelerate in your PhD Research

Question Icon Post Your Answer

Question Icon

Is it physically feasible to design antennas with extremely high gain, such as 131?

Some literature and proposals suggest antennas with gains exceeding 130?dBi, typically for deep-space communication or radio astronomy. I want to understand the physical constraints—size, aperture, diffraction limits, efficiency, and fabrication challenges—that make such designs feasible or practically unattainable.

 

All Answers (1 Answers In All)

By Sato Answered 1 year ago


From my experience studying ultra-high-gain antennas, I have seen that achieving a gain of 131?dBi is theoretically possible but practically extremely challenging. At such levels, the required aperture size becomes enormous—often kilometers in diameter at microwave or millimeter-wave frequencies—to satisfy the basic relation G≈10log?10(4πA/λ2)G approx 10 log_{10}(4pi A/lambda^2)G≈10log10?(4πA/λ2). Diffraction limits, surface tolerance, and efficiency losses mean that even tiny imperfections drastically degrade gain. I would recommend viewing such numbers as primarily theoretical upper bounds; in practice, deep-space antennas or large radio telescopes approach gains in the 70–90?dBi range, while beyond that, mechanical, fabrication, and alignment challenges become prohibitive. Advanced phased arrays could, in principle, combine smaller elements to approximate extreme gain, but maintaining phase coherence across such apertures is a monumental engineering hurdle.
 
 
 

Your Answer