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US 5,881,375 AGranted
Paging transmitter having broadband exciter using an intermediate frequency above the transmit frequency
AssigneeGlenayre Electronics, Inc.
InventorDavid Kent Bonds
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Abstract
The present invention teaches a paging transmitter that has an exciter that upconverts a modulated signal to an intermediate frequency (IF) above that of the transmit frequency. By so doing, the paging transmitter can broadcast a large range of transmit frequencies. Additionally, filtering of unwanted byproducts during the upconversion process is significantly simplified.
Claims2
A paging transmitter comprising:
- a digital modulator coupled to receive digital data, wherein said modulator is capable of providing an in-phase signal and a quadrature signal dependent on said digital data;
- a digital quadrature modulator operative to provide a digital signal dependent on a combination of said in-phase signal and said quadrature signal provided by said digital modulator;
- a digital-to-analog converter coupled to said digital quadrature modulator, wherein said digital-to-analog converter is capable of providing an analog signal dependent on said digital signal provided by said digital quadrature modulator;
- an analog upconverter coupled to said digital-to-analog converter, wherein said analog upconverter is capable of providing a carrier transmission frequency signal dependent on said analog signal provided by said digital-to-analog converter, said analog upconverter including:
- (i) a first mixer for upconverting said analog signal to an intermediate frequency signal having a frequency higher than said carrier transmission frequency signal;
- (ii) a second mixer for downconverting said intermediate frequency signal to said carrier transmission frequency signal;
- a power amplifier coupled to said analog upconverter for amplifying said carrier transmission frequency signal from said analog upconverter;
- and
- an antenna coupled to said power amplifier, wherein said antenna is capable of broadcasting said amplified analog signal provided by said power amplifier.
6 more elements
Dependencies are inferred from the claim text.