The built-in antenna is relative to the external antenna through the signal line link antenna using equipment, built-in antenna is the antenna is integrated in the internal use of equipment, according to the internal structure and matching the selected antenna, advantage is simple and low cost, is easy to be not good for external antenna signal, relative to less. Division I has a built-in antenna of various sizes for customers to choose, but also according to the customer equipment special cases provide debugging, custom service.