| CPC H04B 1/04 (2013.01) | 19 Claims |
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1. A system comprising:
a digital-to-analog converter (DAC) configured to operate at a clock rate (fs) to convert a digital signal to an analog signal, wherein the analog signal comprises analog signal content from signal images in more than one Nyquist region;
a bandpass filter configured to remove a first portion of the analog signal content that is in a lowest Nyquist region of the analog signal, to generate an intermediate-frequency (IF) signal comprising IF signal content that is in Nyquist regions above the lowest Nyquist region, wherein the lowest Nyquist region comprises frequencies between zero and one-half of fs;
a mixer configured to up-convert the IF signal from an output of the bandpass filter to a radio-frequency (RF) signal based on a local oscillator (LO) signal;
a LO circuit configured to generate the LO signal; and
an RF filter configured to generate a filtered signal by at least removing, from the RF signal, first RF signal content that is in a first frequency range that is greater than a difference between a frequency of the LO signal and one-half of fs and less than a sum of the frequency of the LO signal and one-half of fs, resulting in a filtered RF signal, wherein the filtered RF signal comprises second RF signal content in a second frequency range that is greater than the sum of the frequency of the LO signal and one-half of fs, and wherein an output node of the RF filter is configured to be coupled to an antenna for transmission of the RF filtered signal.
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