How in 1966 did the original series Star Trek rip the idea of a mobile phone?

In the Star Trek of the 60s, the communicator is freakishly similar to the cell phone or mobile phone as its known down under , even the trendy “flip” design that many of our phones used was right. Though Capt. Kirk used them to communicate with orbiting starships rather than finding out what his mates were up to, the similarity is astounding, considering that early cell phones, even up to the 90s, resembled Bricks and blocks of mega lego.

Then they pulled out this out. The Next Generation gave the crew an iPad:

 Blown away