Patent ID: 11901922
Assignee: HONEYWELL INTERNATIONAL INC.
Field: Measurement (Instruments)
Classification: CPC H  G | IPC H

Claim 16:
17. 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.