Antenna design links, 2021

A radar with one transmitter and one receiver antenna can measure distances to the targets based on the time of flight of the transmitted electromagnetic wave. One transmitter and receiver isn't however enough to measure angle in which the targets are.
Researchers at the University of California, Berkeley have outlined details of an optical antenna they claim could provide almost limitless bandwidth.
As 5G networking inches closer to reality, one of the more stubborn problems also will be one of the smallest.
5G is gearing up to be the most extensive implementation of mesh networking ever, and that could mean antennas will not need to broadcast for miles, just far enough to reach some devices.
Researchers have devised a method for using an origami-based structure to create radio frequency filters that have adjustable dimensions. The method would enable devices to change which signals they block throughout a large range of frequencies, researchers say.