On September 1, 2026, Japan's Ministry of Internal Affairs and Communications (MIC) published the results of its public consultation on a draft amendment to Notification No. 42 of 1989, the kokuji that sets the uses, radio-wave types and antenna power of specified low-power radio stations. The draft raises the 76.5 GHz millimeter-wave radar antenna-power cap from 0.01 W to 1 W where equivalent isotropically radiated power (EIRP) stays at 50 dBm or below, so that on-board radars can combine a wider field of view with longer-range detection for advanced driver-assistance systems (ADAS) and automated driving.
MIC received 11 comments between July 4 and August 3, 2026, four from corporations or groups and seven from individuals, and changed none of the draft text. It now says it will promptly complete the remaining amendment procedures. Once the amended notification publishes in the Kanpo, the new power limb becomes the Giteki (技適) conformity condition for any 76 GHz specified-low-power radar placed on the Japanese market that uses more than 0.01 W.
What did the 11 comments change in the draft, and what happens next?
Nothing in the legal text. MIC's comment-and-response annex (別紙) records support from Denso and from the millimeter-wave specialist committee of the ITS Info-communications Forum, a product note from Eiko Techno treated as reference only, and a request from the National Astronomical Observatory of Japan (NAOJ) Radio Astronomy Frequency Committee that MIC keep tracking radar penetration and semiconductor output so radio-astronomy coexistence stays valid. Seven individual submissions raised privacy, speed, file accessibility, or opposition without a specified legal change. Every row records "no revision of the draft."
The September 1 results notice states that MIC will promptly complete the remaining amendment procedures. For a kokuji issued under Article 6, paragraph 4, item 2 of the Radio Act Enforcement Regulations, that means ministerial signature and Kanpo publication. No enforcement date is named. The consultation opened on July 3, 2026 (opening notice).
What antenna-power and EIRP limits will actually apply?
The draft comparison table amends only item 11 (millimeter-wave radar) of Notification No. 42 of 1989. Designated frequency 76.5 GHz and the occupied-bandwidth allowance of 1 GHz are unchanged. The sole underlined change is the antenna-power cell:
| Parameter | Current Notification No. 42 | Draft amendment |
|---|---|---|
| Designated frequency | 76.5 GHz | 76.5 GHz (unchanged) |
| Antenna power | 0.01 W or less | 0.01 W or less; 1 W or less if EIRP is 50 dBm or below |
| EIRP implicit today | 0.01 W plus 40 dBi gain, 50 dBm | 50 dBm remains the radiated-power ceiling |
| Licence status | Specified low-power, licence-exempt | Still licence-exempt; Radio Act Article 4, item 3 still caps antenna power at 1 W |
Japan today caps antenna power and antenna gain separately, so lowering gain to widen the beam cuts detection range. The draft copies the EIRP-only approach used in FCC 47 CFR section 95.3367 and ETSI EN 301 091: conducted power may rise to 1 W if gain falls so that EIRP stays at 50 dBm or below. Out-of-band and spurious limits are not amended. The legal basis is the Information and Communications Council's technical conditions under Inquiry No. 2009 of September 30, 2002.
Who has to recertify, and when does the new limb bind?
Registered certification bodies such as TELEC, OEMs and radar module vendors that place 76 GHz specified-low-power radars on the Japanese market, and importers whose ADAS or automated-driving vehicles carry those sensors. Existing 0.01 W certifications remain valid for products that stay at or below 0.01 W. Any construction design that uses the new 1 W limb, or that retunes antenna gain against the 50 dBm EIRP ceiling, needs a fresh Technical Regulations Conformity Certification or Construction Design Certification once the amended notification is in force. Customs will continue to check the Giteki mark at import.
NAOJ's coexistence caveat is operational, not a product-test clause. The Council report found sharing with the Nobeyama 45 m radio telescope acceptable while upgraded-radar penetration stays at or below 0.1 percent, using a 30 dBm practical EIRP rather than the 50 dBm legal ceiling. MIC accepted that a joint interferer and victim working group should keep collecting penetration and semiconductor-output data. That work does not delay the kokuji.
What should Giteki and OEM teams do before Kanpo publication?
Map every 76.0 to 77.0 GHz radar SKU sold into Japan against the two limbs: stay on 0.01 W, or file a new construction-design package that demonstrates EIRP of 50 dBm or less at up to 1 W. Brief the RCB now so characteristic-test methods and antenna-pattern evidence are ready the day the notification publishes. Confirm that occupied bandwidth, out-of-band and spurious numbers still match the current Radio Equipment Regulations. Continuous, per-jurisdiction real-time monitoring surfaces a kokuji like this the moment MIC posts the results, before the Kanpo text hardens the Giteki condition.
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Verify whether any 76 GHz radar you place in Japan will use the new 1 W limb, lock the EIRP evidence pack with your RCB, and watch the Kanpo for the amended Notification No. 42 and its enforcement date. Brief ADAS, homologation and customs teams in the same cycle. Obsidian will keep flagging this file from the results notice through to the binding kokuji.
