Filing is concentrated at the top: the leading assignee alone accounts for 202 of the 1,020 records in scope, and the top five ranked assignees together hold 51.2% of all records. The top ten extend that to 65.0%. Below that group sits a long tail of smaller filers, so freedom-to-operate work should focus first on the handful of companies holding the bulk of the portfolio rather than trying to clear every name in the ranking.

Filings peaked at 104 in 2017 and fell to 9 by 2024, a drop the dataset states as -77% between 2021 and 2024. This looks like a maturing claim space rather than a shrinking market: guided-wave launcher and antenna geometry were heavily claimed early, narrowing the room for new hardware claims. Note that 2025 and 2026 figures in any such dataset are always understated because publication lags filing by about 18 months, so the most recent two years should not be read as confirming a further slowdown.

Guided-wave radar claims, which sit inside the G01F/G01S combination covering the bulk of the corpus, center on a probe or launcher that guides the microwave pulse down a physical conductor into the process fluid. Free-space radar claims instead center on antenna design, most visibly the horn-antenna geometry behind one of the most-cited records in the set (US8890759B2, 222 citations). The two routes carry different fouling and dielectric-sensitivity trade-offs, which is why antenna claims (H01Q) and material-analysis claims (G01N) cluster differently around each.