Short baseline helicopter positioning radar for low visibility using combined phased array and phase difference array receivers
US 8,493,263 Lapsed on the fee recordLapsed Jul 23, 2025 on the fee record · From the USPTO record
20-year base term ends Jun 28, 2031
Third maintenance fee unpaid; grace period ended.
Jun 28, 2011
Jul 23, 2025
Jul 23, 2013
Nov 16, 2031
How we calculated this date
| Step | Input | Date after this step | Confidence |
|---|---|---|---|
| Base term, 20 years from filing | Clock starts Jun 28, 2011, when this application, 13/170,680, was filed | Jun 28, 2031 | High confidence |
| Continuity chain | Every parent in the chain resolved | no change | High confidence |
| Patent term adjustment | +141 days, USPTO patent term adjustment record | Nov 16, 2031 | High confidence |
| Terminal disclaimer cap | None on record | no cap applied | High confidence |
| Patent term extension | None on file | no change | High confidence |
| Fee events | 2 of 3 maintenance fees paid | lapsed Jul 23, 2025 | High confidence |
| Computed term end | The steps above, in order | Jul 23, 2025 | From the USPTO record |
Sources
Google Patents · The patent document at USPTO · Assignment records at USPTO
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Maintenance fee events come from USPTO's own fee records. Its fee lookup asks for the patent number and the application number.
Not on this page: the patent's family, its recorded assignments and its citation count. USPTO's assignment records, linked above, list every recorded assignment.
Every date shows its work: the base term, any term adjustment or extension, any disclaimer cap, and the maintenance fee record, each with a confidence tier. How this record was built
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