What radio antenna connector is required? (FM/AM)
This is a "Motorola" type connector. These have been around in automotive radios since nearly the beginning of auto radios which were introduced by Motorola. Motorola is basically gone but their connector lives on. I've also heard them called "auto antenna" connectors. 

I'm sure there are some different ones on the market but this style is by far the most common. 

According to Wikipedia they are also called DIN41585: 

Motorola Connector