The invention relates to a wireless keyboard capable of operating with a radiation-based
signal receiver of a portable computing apparatus. The wireless keyboard includes
a radiation-based signal transmitter functions converting a corresponding key signal
into a radiation beam and emitting the radiation beam. The radiation beam has a
covered zone. The wireless keyboard also includes a user-adjustable engaging device
having a first end engaging with the housing and a second end where the radiation-based
signal transmitter is fixed. The radiation-based signal transmitter is capable
of approaching the radiation-based signal receiver by adjusting the engaging device.
Thereby, the radiation-based signal receiver is located in the covered zone of
the radiation beam when the wireless keyboard operates with the radiation-based
signal receiver.
