Radio frequency modulator

Details Radio frequency modulator Radio frequency modulator

2006-11-14

2006-11-14

Nguyen, Simon (Department: 2618)

Telecommunications

Transmitter

C455S110000, C455S126000, C375S308000

Reexamination Certificate

active

07136626

ABSTRACT:
A transmitter architecture (200) provides for a stable and low noise modulator where the modulation bandwidth is uncorrelated to the TX loop bandwidth. The output signal (228) of the TX loop is demodulated by a demodulator (208) and the demodulated signal is compared by a comparator (206) with the modulating input signal (202). The output of the comparator is then used to adjust a digital pre-emphasis filter (204) which preconditions the modulating input signal (202) in the digital domain. The preconditioning approach of the present invention provides for low noise because the transmitter designer can chose a narrow band for the TX loop which will also filter out the noise coming from the additional synthesizer (226) used to down convert the input signal.

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