A turn-round is provided in the middle of a plurality of differential amplifiers A1\u2013A4. The method for allocating a time and frequency resource of an RRI includes: allocating codes for an RRI and other uplink control signaling; and multiplexing the RRI and other uplink control signaling in the same time and frequency resource in a code division manner. Each annular segment includes a first portion and a second portion. The core pin has a proximal end defining a surface of the lens portion and a distal end remote from the molding space.