US 2004/0166816 A1Published application

Wireless transmitter

AssigneeTerax Communication Technologies Inc.

InventorsJinn-Ja Chang, Dung-Yun Chen

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Abstract

A wireless transmitter is proposed. First, a ROM having a lookup table therein is provided. The lookup table is used to store a plurality of IF modulation signals so that a state machine can select a corresponding IF modulation signal from the lookup table of the ROM according to loaded data and output a digital IF modulation signal to a DAC, which then converts the digital IF modulation signal into an analog IF modulation signal to be filtered by a low pass filter. Finally, a local oscillator is utilized to modulate the filtered analog IF modulation signal to an emission frequency, hence obtaining an RF signal. The transmitter makes use of a time-sharing way to use a local oscillator together with the receiver. Complexity of device can thus be simplified to meet the requirement of compactness of wireless products.

Claims7

Dependent claims

A wireless transmitter for modulating a loaded data to a radio frequency signal and then emitting out, said transmitter comprising:

a read only memory having a lookup table therein for storing a plurality of intermediate frequency modulation signals;
a state machine for selecting a corresponding intermediate frequency modulation signal from said lookup table of said read only memory according to said loaded data, locking and storing said intermediate frequency modulation signal, and then outputting a digital intermediate frequency modulation signal;
at least a digital-to-analog converter connected to said state machine, said digital-to-analog converter converting said digital intermediate frequency modulation signal into an analog intermediate frequency modulation signal;
at least a low pass filter for filtering said analog intermediate frequency modulation signal;
and
a local oscillator for generating a local oscillation signal and modulating said filtered analog intermediate frequency modulation signal to an emission frequency to obtain said radio frequency signal.

3 more elements

Dependencies are inferred from the claim text.