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US 8,878,575 B1Granted
Noise reduction for non-linear transmission line (NLTL) frequency multiplier
AssigneeRaytheon Company
InventorsJoel Charles Blumke, Ray Soloman Skaggs, Lawrence Wayne Tiffin, Christian Maldonado-Echevarria
Life of this patent
Estimating the term…
Abstract
A noise reduction filter is inserted between the source and non-linear transmission line (NLTL) in a frequency multiplier to improve phase noise performance. The noise reduction filter is suitably coupled directly to the input of the NLTL. The noise reduction filter and the output BPF are suitably low complexity filters.
Claims18
A frequency multiplier, comprising:
- a source configured to generate an input electrical signal at an input frequency F0 and amplitude;
- a noise reduction filter (NRF) configured with a pass band to pass the input electrical signal at the input frequency and a rejection band to reject a band of low frequency 1/f noise below the input frequency where f is frequency, said NRF's rejection band configured to provide at least 10 dB of rejection where the 1/f noise equals a wide band noise floor;
- a non-linear transmission line (NLTL) configured to time delay the input electrical signal as a function of amplitude to generate a plurality of electrical signals at integer multiples of the input frequency, wherein said NRF reduces phase noise in both a main lobe and a side lobe of each said frequency-multiplied electrical signal;
- a band pass filter (BPF) configured with a pass band to pass the main lobe of one of the plurality of electrical signals at a particular integer multiple N of the input frequency as a frequency-multiplied electrical signal and side bands to reject the side lobe of the passed electrical signal and the main and side lobes of all other multiples of the input frequency, wherein the width of the pass band is at least 2 percent of N*F0;
- and
- an amplifier configured to amplify the frequency-multiplied electrical signal.
3 more elements
A frequency multiplier, comprising:
- a source configured to generate an input electrical signal at an input frequency F0 and amplitude;
- a noise reduction filter (NRF) configured with a pass band to pass the input electrical signal at the input frequency and a rejection band to reject a band of low frequency 1/f noise below the input frequency where f is frequency, wherein said noise reduction filter is at most a 5th order filter;
- and
- a non-linear transmission line (NLTL) coupled directly to the NRF, said NLTL configured to time delay the input electrical signal as a function of amplitude to generate a plurality of electrical signals at integer multiples of the input frequency, wherein said NRF reduces phase noise in both a main lobe and a side lobe of each said frequency-multiplied electrical signal;
- a band pass filter (BPF) configured with a pass band to pass the main lobe of one of the plurality of electrical signals at a particular integer multiple N of the input frequency as a frequency-multiplied electrical signal and side bands to reject all other multiples of the input frequency, wherein said BPF is at most a 7th order filter and the width of it's pass band is at least 2 percent of N*F0;
- and
- an amplifier configured to amplify the frequency-multiplied electrical signal.
4 more elements
A frequency multiplier, comprising:
- a source configured to generate an input electrical signal at an input frequency F0 and amplitude, wherein said source is characterized by 1/f noise where f is frequency and a wide band noise floor;
- a noise reduction filter (NRF) configured with a pass band to pass the input electrical signal at the input frequency and a rejection band to reject a band of low frequency 1/f noise below the input frequency, wherein a cut-off frequency Fc that separates the pass band and the rejection band is below the input frequency offset by half the bandwidth of the input electrical signal and wherein the rejection band provides at least 10 dB of rejection at a frequency Ft where 1/f noise equals the wide band noise floor;
- and
- a non-linear transmission line (NLTL) coupled directly to the NRF, said NLTL configured to time delay the input electrical signal as a function of amplitude to generate a plurality of electrical signals at integer multiples of the input frequency, wherein said NRF reduces phase noise in both a main lobe and a side lobe of each said frequency-multiplied electrical signal;
- a band pass filter (BPF) configured with a pass band to pass one of the plurality of electrical signals at a particular integer multiple NF0 of the input frequency as a frequency-multiplied electrical signal and side bands to reject all other multiples of the input frequency, wherein the pass band is between 2 to 5 percent of NF0;
- and
- an amplifier configured to amplify the frequency-multiplied electrical signal.
4 more elements
Dependencies are inferred from the claim text.