Prosecution Insights
Last updated: April 19, 2026
Application No. 19/238,373

Differential Current-Mode Driver for Microwave Assisted Magnetic Recording

Non-Final OA §DP
Filed
Jun 14, 2025
Examiner
TZENG, FRED
Art Unit
2625
Tech Center
2600 — Communications
Assignee
Marvell Asia Pte. Ltd.
OA Round
1 (Non-Final)
87%
Grant Probability
Favorable
1-2
OA Rounds
2y 8m
To Grant
90%
With Interview

Examiner Intelligence

Grants 87% — above average
87%
Career Allow Rate
666 granted / 768 resolved
+24.7% vs TC avg
Minimal +3% lift
Without
With
+3.4%
Interview Lift
resolved cases with interview
Typical timeline
2y 8m
Avg Prosecution
16 currently pending
Career history
784
Total Applications
across all art units

Statute-Specific Performance

§101
1.8%
-38.2% vs TC avg
§103
31.0%
-9.0% vs TC avg
§102
34.5%
-5.5% vs TC avg
§112
21.4%
-18.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 768 resolved cases

Office Action

§DP
DETAILED ACTION Notice of Pre-AIA or AIA Status The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . Claims 1-20 are present for examination. Specification The specification has not been checked to the extent necessary to determine the presence of all possible minor errors. Applicant’s cooperation is requested in correcting any errors of which applicant may become aware in the specification. Double Patenting The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969). A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b). The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13. The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer. Claims 1-10 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-11 of co-pending Application No. 19/241,637 (reference application). Although the claims at issue are not identical, they are not patentably distinct from each other because both set of claims are claiming an apparatus that facilitates a fast transition during microwave-assisted magnetic recording (MAMR) with nearly identical components or features. It would have been obvious to one having ordinary skill in the art before the effective filing date of claimed invention to use the claimed features of the co-pending Application to arrive at the instant claim, yielding predictable results and no more than one having ordinary skill in the art would expect from such an arrangement, as shown below. This is a provisional nonstatutory double patenting rejection because the patentably indistinct claims have not in fact been patented. Instant Application 19/238,373 Reference Co-pending Application 19/241,637 1. An apparatus that facilitates a fast transition during microwave-assisted magnetic recording (MAMR) magnetic recording, the apparatus comprising: a driver circuit configured to provide a controlled differential bias current, the driver circuit having separate source and sink output terminals; a MAMR sensor coupled between the source and sink output terminals through which the MAMR sensor receives the controlled differential bias current provided by the driver circuit, the MAMR sensor having a field-entry terminal and a field-exit terminal for generating microwave fields; and a common-mode feedback (CMFB) loop coupled to the field-entry and field-exit terminals of the MAMR sensor, the CMFB loop forming a feedback pathway with the driver circuit, the CMFB loop configured to detect common-mode voltage (CMV) and adjust the controlled differential bias current to maintain CMV regulation of the MAMR sensor. 1. An apparatus that facilitates a fast transition during microwave-assisted magnetic recording (MAMR) magnetic recording, the apparatus comprising: a driver circuit configured to provide controlled bias current, the driver circuit having separate source and sink output terminals and being responsive to feedback signals; a MAMR sensor coupled between the source and sink output terminals through which the MAMR sensor receives the controlled bias current provided by the driver circuit; a common-mode feedback (CMFB) loop coupled to the source and sink output terminals of the driver circuit, the CMFB loop configured to detect common-mode voltage (CMV) and provide feedback signals to the driver circuit to maintain CMV regulation of the MAMR sensor; and a differential voltage regulation loop coupled to the source and sink output terminals of the driver circuit, the differential voltage regulation loop configured to provide feedback signals to maintain a voltage differential of the MAMR sensor at a reference value. Instant Application 19/238,373 Reference Co-pending Application 19/241,637 Claim 2 Claim 3 Claim 4 Claim 5 Claim 6 Claim 7 Claim 8 Claim 9 Claim 10 Claim 2 Claim 3 Claim 4 Claim 5 Claim 6 Claim 7 Claim 8 Claim 11 Claim 10 Claims 11-17 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 12-17 of co-pending Application No. 19/241,637 (reference application). Although the claims at issue are not identical, they are not patentably distinct from each other because both set of claims are claiming a hard-disk drive system that facilitates a fast transition during microwave-assisted magnetic recording (MAMR) magnetic recording with nearly identical components or features. It would have been obvious to one having ordinary skill in the art before the effective filing date of claimed invention to use the claimed features of the co-pending Application to arrive at the instant claim, yielding predictable results and no more than one having ordinary skill in the art would expect from such an arrangement, as shown below. This is a provisional nonstatutory double patenting rejection because the patentably indistinct claims have not in fact been patented. Instant Application 19/238,373 Reference Co-pending Application 19/241,637 11. A hard-disk drive system that facilitates a fast transition during microwave-assisted magnetic recording (MAMR) magnetic recording, the hard-disk drive system comprising: a write head employing a MAMR sensor; and a current-mode (iMode) driver circuitry configured to drive a controlled differential bias current through a field-entry terminals and a field-exit terminals of the MAMR sensor, the iMode driver circuitry comprising: a driver circuit configured to provide a controlled differential bias current, the driver circuit having separate source and sink output terminals through which the MAMR sensor receives the controlled differential bias current; and a common-mode feedback (CMFB) loop coupled to the field-entry and field-exit terminals of the MAMR sensor, the CMFB loop forming a feedback pathway with the driver circuit, the CMFB loop configured to detect common-mode voltage (CMV) and adjust the controlled differential bias current to maintain CMV regulation of the MAMR sensor. 12. A hard-disk drive system that facilitates a fast transition during microwave-assisted magnetic recording (MAMR) magnetic recording, the hard-disk drive system comprising: a write head including a microwave-assisted magnetic recording (MAMR) sensor; a voltage-mode (vMode) driver circuitry configured to drive a differential voltage of the MAMR sensor, the vMode driver circuitry including: a driver circuit configured to be responsive to feedback signals and has separate source and sink terminals between which the MAMR sensor is coupled; a current-mode feedback (CMFB) loop coupled to the source and sink output terminals of the driver circuit, the CMFB loop configured to detect common-mode voltage (CMV) and provide feedback signals to the driver circuit to maintain CMV regulation of the MAMR sensor; and a differential voltage regulation loop coupled to the source and sink output terminals of the driver circuit, the differential voltage regulation loop configured to provide feedback signals to maintain a voltage differential of the MAMR sensor at a reference value. Instant Application 19/238,373 Reference Co-pending Application 19/241,637 Claim 12 Claim 13 Claim 14 Claim 15 Claim 16 Claim 17 Claim 13 Claim 15 Claim 16 Claim 17 Claim 17 Claim 14 Claims 18-20 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 18-20 of co-pending Application No. 19/241,637 (reference application). Although the claims at issue are not identical, they are not patentably distinct from each other because both set of claims are claiming a method that facilitates a fast transition during microwave-assisted magnetic recording (MAMR) magnetic recording with nearly identical components or features or method. It would have been obvious to one having ordinary skill in the art before the effective filing date of claimed invention to use the claimed features/method of the co-pending Application to arrive at the instant claim, yielding predictable results and no more than one having ordinary skill in the art would expect from such an arrangement, as shown below. This is a provisional nonstatutory double patenting rejection because the patentably indistinct claims have not in fact been patented. Instant Application 19/238,373 Reference Co-pending Application 19/241,637 18. A method that facilitates a fast transition during microwave-assisted magnetic recording (MAMR) magnetic recording, the method comprising: providing, by a driver circuit, a controlled differential bias current to a MAMR sensor of a magnetic media read/write channel; maintaining, by a common-mode feedback (CMFB) loop coupled to field-entry and field-exit terminals of the MAMR sensor, a common-mode voltage (CMV) regulation of the MAMR sensor; and switching the controlled differential bias current through the MAMR sensor with: a rise time of ten nanosecond or less; and a fall time of ten nanosecond or less. 18. A method that facilitates a fast transition during microwave-assisted magnetic recording (MAMR) magnetic recording, the method comprising: providing a reference value for a voltage differential; providing, by a driver circuit, a bias current to a MAMR sensor of a magnetic media read/write channel; maintaining, by a common-mode feedback (CMFB) loop coupled to the driver circuit, a common-mode voltage (CMV) regulation of the MAMR sensor; maintaining the voltage differential across the MAMR sensor at the reference value; and switching the voltage differential across the MAMR sensor with rise and fall times of twenty nanosecond or less. Instant Application 19/238,373 Reference Co-pending Application 19/241,637 Claim 19 Claim 20 Claim 19 Claim 20 Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Johns et al (USPN 8,760,779) Any inquiry concerning this communication from the examiner should be directed to FRED TZENG whose telephone number is 571-272-7565. The examiner can normally be reached on weekdays from 2:0 pm to 10:00 pm. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, William Boddie can be reached on 571-272-0666. The fax phone numbers for the organization where this application or proceeding is assigned are 571-273-8300 for regular communications and 571-273-7565 for After Final communications. Informal regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docs for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000 (IN USA). /FRED TZENG/ Primary Examiner, Art Unit 2625 FFT February 07, 2026
Read full office action

Prosecution Timeline

Jun 14, 2025
Application Filed
Feb 07, 2026
Non-Final Rejection — §DP (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
87%
Grant Probability
90%
With Interview (+3.4%)
2y 8m
Median Time to Grant
Low
PTA Risk
Based on 768 resolved cases by this examiner. Grant probability derived from career allow rate.

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