Back to results
US 11,901,922 B2Granted
Radio-frequency transmitter
AssigneeHoneywell International Inc.
InventorDavid Larsen
Life of this patent
Estimating the term…
Abstract
In some examples, a system includes a digital-to-analog converter (DAC) configured to operate at a clock rate; a mixer configured to up-convert an intermediate-frequency (IF) signal from the DAC to a radio-frequency (RF) signal based on a local oscillator (LO) signal; and an RF filter configured to generate a filtered signal by at least removing, from the RF signal, frequency components greater than a difference between a frequency of the LO signal and one-half of the clock rate and less than a sum of a frequency of the LO signal and one-half of the clock rate, wherein an output node of the RF filter is configured to be coupled to an antenna for transmission of the filtered signal.
Claims19
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.
3 more elements
A method comprising:
- converting, by a digital-to-analog converter (DAC) based on a clock rate (fs), a digital signal to an analog signal comprising analog signal content from signal images in more than one Nyquist region;
- filtering out, by a bandpass filter, a first portion of the analog signal content that is within a lowest Nyquist region 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;
- up-converting, by a mixer based on a local oscillator (LO) signal, the IF signal from an output of the DAC to a radio-frequency (RF) signal;
- generating the LO signal with an LO circuit;
- filtering the RF 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
- transmitting the filtered RF signal.
4 more elements
A system comprising:
- a field-programmable gate array (FPGA) configured to encode a surveillance message in a digital signal;
- a digital-to-analog converter (DAC) configured to convert the digital signal to an analog signal, comprising analog signal content from signal images in more than one Nyquist region, based on a clock rate (fs);
- a bandpass filter configured to remove, analog signal content in a lowest Nyquist region from the analog signal to generate an intermediate-frequency (IF) signal, wherein the lowest Nyquist region comprises frequencies between zero and one-half of fs;
- a local oscillator (LO) circuit configured to generate an LO signal;
- a mixer configured to up-convert the IF signal to a radio-frequency (RF) signal based on the LO signal;
- a LO circuit configured to generate the LO signal;
- and
- a 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 RF filtered 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.
5 more elements
Dependencies are inferred from the claim text.