A reading apparatus for reading a wireless tag, such as an RFID tag, comprises a housing having a chamber and an opening providing an entrance to the chamber. A door attached to the housing and covers the opening when closed and permits access to the chamber when opened. A detector is proximate to a first portion of the housing and is configured to detect whether the door is opened or closed. The first portion of the housing faces the door when the door is closed. An antenna within the housing is configured to emit a radio wave to read information from wireless tags inside the chamber. A shielding portion is disposed adjacent to the detector to prevent the radio wave emitted by the antenna from leaking to the outside of the housing through the first portion of the housing.

An example configurable radio-frequency identification (RFID) reader assembly includes a base unit and an integrable multiplexer. The base unit includes a first housing, a printed circuit board (PCB), an internal multiplexer, a first plurality of antenna ports accessible from outside the first housing, and a first radio-frequency (RF) connector accessible from outside the first housing. The integrable multiplexer is attached to the first housing and includes a second housing that is attachable to and removable from the first housing from outside the first housing, a second plurality of antenna ports accessible from outside of the second housing, and a second RF connector accessible from outside the integrable multiplexer housing and connected to the first RF connector.