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US 5,857,145 AGranted
Radio pager
AssigneeNEC Corporation
InventorYukio Miyashita
Life of this patent
Estimating the term…
Abstract
A radio pager of the present invention is capable of determining, during automatic area switching operation, a frequency having a high field strength by excluding the other frequencies having low field strengths. In addition, the pager is capable of determining such a frequency simply at low cost by use of its original antenna and radio frequency gain control function, i.e., without resorting to any additional circuitry.
Claims3
A radio pager having an automatic area switching operation mode for receiving a call in a plurality of service areas at a particular radio frequency, said radio pager comprising:
- an antenna for receiving a signal transmitted at the radio frequency;
- an RF section for receiving and demodulating, one at a time, a plurality of signals input from said antenna and each having a particular radio frequency;
- a channel controller for varying a receipt frequency of said antenna or a receipt frequency of said RF section, depending on whether or not a synchronizing signal included in the signal demodulated is received;
- a gain controller for decreasing reception sensitivity by decreasing the gain of said antenna or the gain of said RF section when synchronizing signals are correctly received over a plurality of channels;
- and
- a controller for controlling said channel controller and said gain controller in order to determine a reception frequency having a highest field strength.
3 more elements
Dependencies are inferred from the claim text.