What is the Physical Connection Method of RF Modules?

There ae mainly 3 physical connection methods of RF modules: Land grid array, Through-hole, and Castellated boardlet (from left to right as shown below

A variety of methods are used to attach an RF module to a printed circuit board, either with through-hole technology or surface-mount technology. 

Through-hole technology allows the module to be inserted or removed without soldering. Surface-mount technology allows the module to be attached to the PCB without an additional assembly step. 

Surface-mount connections used in RF modules include land grid array (LGA) and castellated pads. The LGA package allows for small module sizes as the pads are all beneath the module but connections must be X-rayed to verify connectivity. 

Castellated Holes enable optical inspection of the connection but will make the module footprint physically larger to accommodate the pads.