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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submissions filed on January 4, 2026 and January 21, 2026 have been entered.
Response to Amendment
The amendments filed January 4, 2026 and January 21, 2026 have been entered. Claims 1-5 and 8-10 remain pending in the application. Applicant’s amendments to the claims have overcome each and every 35 U.S.C. § 112 rejection previously presented in the Final Rejection mailed October 22, 2025.
Response to Arguments
Applicant's arguments filed January 4, 2026 and January 21, 2026 have been fully considered but they are not persuasive. Examiner notes that both sets of arguments are identical, and the following applies to both responses.
Applicant argues, see pages 6-8, that first, previously presented prior art reference Kirino et al. (Patent Publication Number JP H07154162 A), hereafter referred to as Kirino, fails to disclose the claimed connection method due to the structural differences between Kirino and the instant application, that second, Kirino fails to disclose the claimed connection method due to the function differences between Kirino and the instant application, that third, previously presented prior art reference Goto et al. (Patent Publication Number US 2022/0021341 A1), hereafter referred to as Goto, and Kirino do not suggest a combination with each other, rendering a combination of the references as impermissible hindsight, and that fourth, the combination of Goto and Kirino does not disclose the claimed invention. Examiner respectfully disagrees.
Regarding the first argument, in response to applicant's arguments against the references individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986).
Applicant argues that the lack of transformers in Kirino renders Kirino as unable to overcome the shortcomings of Goto. However, Kirino does not need to disclose transformer connections, because the amplifiers of Goto include transformers between them. Kirino teaches using an inverted connection between differential amplifiers to reduce signal offsets (Kirino, Page 3, Paragraph 5, lines 1-6). Therefore, Kirino suggests modifying Goto to include an inverted connection such that the signal phase between amplifier stages is inverted, which would require an inverted connection between either the output of the first differential amplifier and the input of the transformer or the output of the transformer and the input of the second differential amplifier, otherwise the signal phase inversion necessary to achieve the benefits described in Kirino wouldn’t be achieved. Therefore, it would have been obvious for Kirino to teach “wherein in the inverted connection between each differential amplifier in the plurality of the differential amplifier and the corresponding transformer, an output terminal of each differential amplifier in the plurality of differential amplifiers is invertedly connected to an input terminal of the corresponding transformer” as the claimed connection method is one of just two equivalent ways to implement the benefits described in Kirino in the circuit of Goto. Therefore, the first argument presented by the applicant is unconvincing.
Regarding the second argument, in response to applicant's argument that the purpose taught by the prior art of reducing signal offsets is different than applicant’s purpose of reducing the ground bounce signal, the fact that the inventor has recognized another advantage which would flow naturally from following the suggestion of the prior art cannot be the basis for patentability when the differences would otherwise be obvious. See Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985).
As discussed above, the connection differences between the primary prior art reference Goto and the instant application are rendered obvious by combination with Kirino, and therefore the second argument presented by the applicant is unconvincing. Furthermore, in response to applicant's argument that the references fail to show certain features of the invention, it is noted that the features upon which applicant relies (i.e., that the inverted connection between differential amplifiers and corresponding transformers reduce the ground bounce signal) are not recited in the rejected claims. Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993). For this additional reason, applicant’s second argument is further shown to be unconvincing.
Regarding the third argument, in response to applicant's argument that the examiner's conclusion of obviousness is based upon improper hindsight reasoning, it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971).
In this case, replacing a regular connection between a differential amplifier and a corresponding transformer in Goto with an inverted connection is well within the level of ordinary skill in the art, based on the teachings of Kirino, which suggest inverting a connection between differential amplifiers to reduce signal offsets (Kirino, Page 3, Paragraph 5, lines 1-6). Therefore, the third argument is unconvincing.
Regarding the fourth argument, applicant's arguments fail to comply with 37 CFR 1.111(b) because they amount to a general allegation that the claims define a patentable invention without specifically pointing out how the language of the claims patentably distinguishes them from the references. As discussed above, one of ordinary skill in the art would have been motivated to arrive at the claimed invention because invertedly coupling an output terminal of a differential amplifier to a corresponding transformer is one of just two equivalent ways to implement the teachings of Kirino in the circuit of Goto to realize the benefit taught by Kirino of reducing signal offsets. Therefore the fourth argument is unconvincing. Therefore, all of applicant’s arguments are unconvincing and the rejections of claims 1-5 and 8-10 are maintained.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-5 and 8-10 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 1 recites the limitation “corresponding transformers” in line 24. There is insufficient antecedent basis for this limitation in the claim. Amending the limitation to “the corresponding transformers” is sufficient to overcome this rejection, which is how the limitation will be treated for examination purposes. Claims 2-5 and 8-10 are likewise rejected under this logic by virtue of their dependency on claim 1.
Appropriate correction is required.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-5 and 8-10 are rejected under 35 U.S.C. 103 as being unpatentable over Goto in view of Kirino.
Regarding claim 1, Goto discloses:
A differential amplifier circuit (Goto, Fig. 13), comprising a plurality of differential amplifiers (Fig. 13, see 11a/b and 12a/b) and a plurality of transformers (Fig. 13, see 21 and 22), wherein the plurality of differential amplifiers are connected in series (Fig. 13, see connection between 11a/b and 12a/b): each differential amplifier in the plurality of differential amplifiers is correspondingly connected to one of the transformers in the plurality of transformers (Fig. 13, see connection between 11a/b and 21, and between 12a/b and 22), and one of the transformers in the plurality of transformers is connected between different differential amplifiers (Fig. 13, see connection between 11a/b and 12a/b via transformer 21); the plurality of differential amplifiers connected in series are divided into M groups (Goto, Fig. 13, consider amplifier 11a/b form a first group, and amplifier 12a/b form a second group), wherein a number of stages of M-1 groups of the plurality of differential amplifiers is
N
M
(consider that the first group has 1 differential amplifier according to this formula), N represents a number of stages of the plurality of differential amplifiers connected in series (Fig. 13, see that N = 2),
represents downward rounding (consider that N/M rounds down to 1 for N = 2, M = 2), and a number of stages of a remaining group of the plurality of differential amplifiers is
N
-
M
-
1
*
N
M
(consider that the second group has 1 differential amplifier according to this formula); a second connection between differential amplifiers in an even group and corresponding transformers is set to be same-phase connection, [or] the second connection between the differential amplifiers in the odd group and the corresponding transformers is set to be same-phase connection (Goto, Fig. 13, see that connection between 12a/b and 22 is same-phase connection [2nd amplifier stage]), but fails to disclose and at least one of the differential amplifiers in the plurality of differential amplifiers is invertedly connected to a corresponding transformer, wherein in the inverted connection between each differential amplifier in the plurality of the differential amplifier and the corresponding transformer, an output terminal of each of the differential amplifiers is invertedly connected to an input terminal of the corresponding transformer, wherein in the inverted connection between at least one of the differential amplifiers in the plurality of differential amplifiers and the corresponding transformer, and a first connection between differential amplifiers in an odd group and corresponding transformers is set to be inverted-phase connection, or the first connection between the differential amplifiers in the even group and corresponding transformers is set to be inverted-phase connection.
However, Kirino teaches and at least one of the differential amplifiers in the plurality of differential amplifiers is invertedly connected to a corresponding transformer (Kirino, Fig. 1, see inverted connection between amplifiers A2 and A3 in modified Fig. 1 below), wherein in the inverted connection between each differential amplifier in the plurality of the differential amplifier and the corresponding transformer, an output terminal of each of the differential amplifiers is invertedly connected to an input terminal of the corresponding transformer (Fig. 1, see inverted connection between amplifiers A2 and A3 in modified Fig. 1 above), wherein in the inverted connection between at least one of the differential amplifiers and the corresponding transformer, and a first connection between the differential amplifiers in an odd group and the corresponding transformers is set to be inverted-phase connection, or the first connection between the differential amplifiers in the even group and corresponding transformers is set to be inverted-phase connection (Fig. 1, see inverted connection between amplifiers A2 and A3 in modified Fig. 1 above [consider combining Kirino with Goto to modify the connection at the output of the 1st amplifier stage]).
Goto and Kirino are both considered to be analogous to the claimed invention because they are in the same field of improving differential amplifiers. Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have modified Goto to incorporate the teachings of Kirino to couple the differential amplifiers of Goto with an inverted connection, which would have the effect of reducing signal offsets associated with coupling multiple amplifiers in series (Kirino, Page 3, Paragraph 5, lines 1-6).
PNG
media_image1.png
204
432
media_image1.png
Greyscale
Regarding claim 2, Goto further discloses:
and a second connection between other differential amplifiers and corresponding transformers is same-phase connection (Goto, Fig. 13, see that connection between 12a/b and 22 is same-phase connection), but fails to disclose wherein in the inverted connection between at least one of the differential amplifiers in the plurality of differential amplifiers and the corresponding transformer, a first connection between at least one of the differential amplifiers in the plurality of differential amplifiers and the corresponding transformer is inverted-phase connection.
However, Kirino further teaches wherein in the inverted connection between at least one of the differential amplifiers and the corresponding transformer, a first connection between at least one of the differential amplifiers in the plurality of differential amplifiers and the corresponding transformer is inverted-phase connection (Kirino, Fig. 1, see inverted connection between amplifiers A2 and A3 in modified Fig. 1 above).
Goto and Kirino are both considered to be analogous to the claimed invention because they are in the same field of improving differential amplifiers. Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have modified Goto to incorporate the teachings of Kirino to couple the differential amplifiers of Goto with an inverted connection, which would have the effect of reducing signal offsets associated with coupling multiple amplifiers in series (Kirino, Page 3, Paragraph 5, lines 1-6).
Regarding claim 3, Goto further discloses:
and a second connection between other differential amplifiers and corresponding transformers is same-phase connection (Goto, Fig. 13, see that connection between 12a/b and 22 is same-phase connection), but fails to disclose wherein in the inverted connection between at least one of the differential amplifiers in the plurality of differential amplifiers and the corresponding transformer, a first connection between half of the plurality of differential amplifiers connected in series and corresponding transformers is inverted-phase connection.
However, Kirino further teaches wherein in the inverted connection between at least one of the differential amplifiers and the corresponding transformer, a first connection between half of the plurality of differential amplifiers connected in series and corresponding transformers is inverted-phase connection (Kirino, Fig. 1, see inverted connection between amplifiers A2 and A3 in modified Fig. 1 above).
Goto and Kirino are both considered to be analogous to the claimed invention because they are in the same field of improving differential amplifiers. Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have modified Goto to incorporate the teachings of Kirino to couple the differential amplifiers of Goto with an inverted connection, which would have the effect of reducing signal offsets associated with coupling multiple amplifiers in series (Kirino, Page 3, Paragraph 5, lines 1-6).
Regarding claim 4, Goto further discloses:
and the second connection between differential amplifiers of odd stages and corresponding transformers is the same-phase connection, or the second connection between the differential amplifiers of even stages in the plurality of differential amplifiers connected in series and the corresponding transformers is the same-phase connection (Goto, Fig. 13, see that connection between 12a/b and 22 is same-phase connection [2nd amplifier stage]), but fails to disclose wherein the first connection between differential amplifiers of even stages in the plurality of differential amplifiers connected in series and corresponding transformers is the inverted-phase connection, [or] the first connection between the differential amplifiers of odd stages and the corresponding transformers is the inverted-phase connection.
However, Kirino further teaches wherein the first connection between differential amplifiers of even stages in the plurality of differential amplifiers connected in series and corresponding transformers is the inverted-phase connection, [or] the first connection between the differential amplifiers of odd stages and the corresponding transformers is the inverted-phase connection (Kirino, Fig. 1, see inverted connection between amplifiers A2 and A3 in modified Fig. 1 above [consider combining Kirino with Goto to modify the connection at the output of the 1st amplifier stage]).
Goto and Kirino are both considered to be analogous to the claimed invention because they are in the same field of improving differential amplifiers. Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have modified Goto to incorporate the teachings of Kirino to couple the differential amplifiers of Goto with an inverted connection, which would have the effect of reducing signal offsets associated with coupling multiple amplifiers in series (Kirino, Page 3, Paragraph 5, lines 1-6).
Regarding claim 5, Goto further discloses:
and the second connection between other differential amplifiers and corresponding transformers is the same-phase connection; or the second connection between the differential amplifiers of first
N
2
stages in the plurality of differential amplifiers connected in series and the corresponding transformers is the same-phase connection (Goto, Fig. 13, see that connection between 12a/b and 22 is same-phase connection [2nd amplifier stage]), wherein N represents the number of stages of the plurality of differential amplifiers connected in series (Fig. 13, see that N = 2), and
represents downward rounding (consider that N/2 rounds down to 1 for N = 2), but fails to disclose wherein the first connection between differential amplifiers of first
N
2
stages in the plurality of differential amplifiers connected in series and corresponding transformers is the inverted-phase connection, [or] the first connection between other differential amplifiers and the corresponding transformers is the inverted-phase connection.
However, Kirino teaches wherein the first connection between differential amplifiers of first
N
2
stages in the plurality of differential amplifiers connected in series and corresponding transformers is the inverted-phase connection, [or] the first connection between other differential amplifiers and the corresponding transformers is the inverted-phase connection (Kirino, Fig. 1, see inverted connection between amplifiers A2 and A3 in modified Fig. 1 above [consider combining Kirino with Goto to modify the connection at the output of the 1st amplifier stage]).
Goto and Kirino are both considered to be analogous to the claimed invention because they are in the same field of improving differential amplifiers. Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have modified Goto to incorporate the teachings of Kirino to couple the differential amplifiers of Goto with an inverted connection, which would have the effect of reducing signal offsets associated with coupling multiple amplifiers in series (Kirino, Page 3, Paragraph 5, lines 1-6).
Regarding claim 8, Goto further discloses:
wherein each differential amplifier in the plurality of differential amplifiers comprises two parallel branches connected in parallel (Goto, Fig. 13, see parallel branches 11a/11b and 12a/12b that each form a differential amplifier), and each parallel branch comprises one transistor or two transistors connected in series (Fig. 8, see example implementation of parallel branches 12a/12b as comprising one transistor).
Regarding claim 9, Goto further discloses:
wherein the plurality of differential amplifiers are microwave differential amplifiers (Goto, Paragraph 35, lines 1-8).
Regarding claim 10, Goto further discloses:
An electronic device (Goto, Fig. 13), comprising the differential amplifier circuit according to claim 1 (see above).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Mehr et al. (Patent Publication Number US 2023/0179162 A1) discloses (Fig. 1) a differential amplifier comprising two parallel branches of two series transistors.
Dunworth et al. (Patent Publication Number US 2019/0173439 A1) discloses (Fig. 6) a differential amplifier comprising three amplifier stages with interstage transformers.
Corbishley (Patent Publication Number US 2017/0346456 A1) discloses (Fig. 2) a differential amplifiers comprising four amplifier stages with alternating same/inverted phase couplings.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Lance T Bartol whose telephone number is (703)756-1267. The examiner can normally be reached Monday - Thursday 6:30 a.m. - 4:00 p.m. CT, Alternating Fridays 6:30 - 3:00.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Andrea Lindgren Baltzell can be reached at 571-272-5918. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information 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/docx 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.
/LANCE TORBJORN BARTOL/Examiner, Art Unit 2843
/ANDREA LINDGREN BALTZELL/Supervisory Patent Examiner, Art Unit 2843