| 摘要 |
A compact and unitary cellular/pager. The cellular/pager includes a cellular antenna for receiving UHF cellular and paging signals. The cellular/pager also includes a VHF paging antenna. Every paging signal is sent to a paging receiver. The paging receiver uses the same circuitry to process either the UHF or VHF page. This is accomplished by setting a voltage controlled oscillator (VCO) to one of two frequency ranges. The chosen frequency is either added or subtracted to the incoming signal in order to match a constant intermediate frequency. The resultant signal is demodulated and a bit rate is selected by a decoder, under the control of a microprocessor. Therefore, the paging receiver can choose a band, a channel and a bit rate. Cellular signals are sent to a cellular block. Cellular location information is utilized by the cellular/pager to form an internally updated roaming pager. That is, the cellular location information is automatically conveyed by the cellular block, under the control of the microprocessor, to a paging service. The paging service then knows the location of the paging receiver, consequently the paging service can direct the pager to await for a page at a single frequency, thereby eliminating frequency scanning by the pager or manual updates by the user. |
