Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4888701 | Apparatus for measuring vector voltage ratio | Hideshi Tanaka | 1989-12-19 |
| 4820969 | Polarity compensated apparatus for measuring the impedance of a polar device | Takanori Yonekura | 1989-04-11 |