Prosecution Insights
Last updated: April 19, 2026
Application No. 18/620,047

RADIO FREQUENCY FRONT-END CIRCUIT

Non-Final OA §103
Filed
Mar 28, 2024
Examiner
TRAN, TUAN A
Art Unit
2648
Tech Center
2600 — Communications
Assignee
Huawei Technologies Co., Ltd.
OA Round
1 (Non-Final)
85%
Grant Probability
Favorable
1-2
OA Rounds
2y 7m
To Grant
92%
With Interview

Examiner Intelligence

Grants 85% — above average
85%
Career Allow Rate
658 granted / 774 resolved
+23.0% vs TC avg
Moderate +7% lift
Without
With
+7.4%
Interview Lift
resolved cases with interview
Typical timeline
2y 7m
Avg Prosecution
18 currently pending
Career history
792
Total Applications
across all art units

Statute-Specific Performance

§101
4.1%
-35.9% vs TC avg
§103
42.9%
+2.9% vs TC avg
§102
30.4%
-9.6% vs TC avg
§112
7.3%
-32.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 774 resolved cases

Office Action

§103
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 . Claim Rejections - 35 USC § 103 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 21-22, 25, 31-32, 35 and 40 are rejected under 35 U.S.C. 103 as being unpatentable over Wloczysiak (2023/0361850) in view of Nagayama (8,396,435). Regarding claims 21-22 and 40, Wloczysiak discloses a radio frequency front-end circuit of a transceiver (See figs. 19-20 and par [0112, 0114-0115]), comprising: PNG media_image1.png 762 832 media_image1.png Greyscale a first switch group {S3, S4} (See fig. 12G), comprising a first output end and a second output end, wherein the first switch group is configured to selectively transmit, to the first output end and the second output end, a carrier aggregation signal received from an antenna (See figs. 12D-12G, 20 and par [0115]), wherein the carrier aggregation signal comprises at least a first frequency band signal (i.e. HB such as Band 7 or B7), a second frequency band signal (i.e. MB such as Band 1/Band 3 or B1/B3), and a third frequency band signal (i.e. MLB such as Band 32 or B32) (See par [0053]) that are aggregated, wherein the first output end is coupled to a first filter 108, wherein the first filter is configured to: perform filtering on the carrier aggregation signal, and output the first frequency band signal; a phase-shifter 142 coupled to the second output end, the phase-shifter configured to: perform phase-shifting on the carrier aggregation signal; and output a phase-shifted signal, wherein the phase-shifted signal comprises the second frequency band signal and the third frequency band signal (See fig. 12G); and a second switch group {S1, S2}, coupled to the phase-shifter, wherein the second switch group comprises at least one third output end, wherein each third output end is configured to output the phase-shifted signal, wherein the at least one third output end is coupled to a second filter 106 and a third filter 104, and wherein the second filter and the third filter are configured to: perform, separately, filtering on the phase-shifted signal; and output, respectively, the second frequency band signal and the third frequency band signal (See fig. 12G and par [0098]). However, Wloczysiak does not explicitly mention the phase-shifter 142 is a phase-shift filter configured to: perform phase-shifting on the first frequency band signal; and filter out the first frequency band signal. Since phase-shift filter is widely known in the art as suggested by Nagayama (See fig. 4 and col. 9 lines 45-50); therefore, it would have been obvious to one skilled in the art to utilize the phase shift filter, as suggested by Nagayama, for the system of Wloczysiak to perform phase-shifting on the first frequency band signal; and filter out the first frequency band signal, for the advantage of filtering out unwanted signals (i.e. unwanted frequency and/or band) to accommodate the design intention. Regarding claim 25, Wloczysiak & Nagayama disclose as cited in claim 21. Wloczysiak further discloses the radio frequency front-end circuit further comprises the second filter 106 and the third filter 104, wherein, when there are a plurality of third output ends, the second filter and the third filter are separately coupled to one of the third output ends, wherein the second filter is configured to: filter out the third frequency band signal from the phase-shifted filtered signal; and output the second frequency band signal; and wherein the third filter is configured to: filter out the second frequency band signal from the phase-shifted filtered signal; and output the third frequency band signal (See fig. 12G). Regarding claims 31-32, Wloczysiak discloses a radio frequency front-end circuit (See figs. 19-20 and par [0112, 0114-0115]), comprising: PNG media_image2.png 762 832 media_image2.png Greyscale a first switch group {S3, S4} (See fig. 12G), comprising a first input end, wherein the first input end is coupled to a first filter 108, wherein the first filter is configured to output a first frequency band signal (i.e. Band 7 or B7) to the first input end; and a second switch group {S1, S2}, comprising at least one second input end, wherein the at least one second input end is coupled to a second filter 106 and a third filter 104, wherein the second filter and the third filter are configured to output, respectively, a second frequency band signal (i.e. B1/B3) and a third frequency band signal (i.e. B32) to the at least one second input end, wherein the second switch group is further coupled to a phase-shifter 142, wherein the second switch group is configured to selectively output the second frequency band signal and the third frequency band signal to the phase-shifter (See figs. 12D-12G), wherein the phase-shifter is coupled to a third input end of the first switch group, wherein the phase-shifter is configured to: perform phase-shifting on a received frequency band signal; and output a phase-shifted signal to the third input end of the first switch group, wherein the phase-shifted signal comprises the second frequency band signal and the third frequency band signal, and wherein the first switch group is configured to selectively transmit the first frequency band signal and the phase-shifted signal to an antenna (See figs. 12D-12G, 20 and par [0115]), wherein the first frequency band signal and the phase-shifted filtered signal are aggregated by the antenna into a carrier aggregation signal, and wherein the carrier aggregation signal is transmitted (See fig. 12G, 20 and par [0098]). However, Wloczysiak does not explicitly mention the phase-shifter 142 is a phase-shift filter configured to: perform phase-shifting on the first frequency band signal; and filter out the first frequency band signal (i.e. reception). Since phase-shift filter is widely known in the art as suggested by Nagayama (See fig. 4 and col. 9 lines 45-50); therefore, it would have been obvious to one skilled in the art to utilize the phase shift filter, as suggested by Nagayama, for the system of Wloczysiak to perform phase-shifting on the first frequency band signal; and filter out the first frequency band signal, for the advantage of filtering out unwanted signals (i.e. unwanted frequency and/or band) to accommodate the design intention. Regarding claim 35, Wloczysiak & Nagayama disclose as cited in claim 31. Wloczysiak further discloses the radio frequency front-end circuit further comprises the second filter 106 and the third filter 108, wherein, when there are a plurality of second input ends, the second filter and the third filter are separately coupled to one of the plurality of second input ends, wherein the second filter is configured to: filter out the third frequency band signal from the received frequency band signal; and output the second frequency band signal, and wherein the third filter is configured to: filter out the second frequency band signal from the received frequency band signal; and output the third frequency band signal (See fig. 12G). Claims 23-24, 26, 33-34 and 36 are rejected under 35 U.S.C. 103 as being unpatentable over Wloczysiak & Nagayama as applied to claims 21-22, 25, 31-32 and 35 above, and further in view of Balm (9,998,153). Regarding claim 23, Wloczysiak & Nagayama disclose as cited in claim 22. However, they do not mention that after phase-shifting, an impedance of a frequency range of the first frequency band signal is in a high impedance state in the phase-shift filter. Since Balm teaches a front-end for CA mode, wherein a phase shifter is adapted to provide a high impedance state for signals within the band of other signal path (See fig. 1 and col. 2 lines 11-18); therefore, it would have been obvious to one skilled in the art to apply the teaching of Balm in modifying the phase-shift filter 142, as disclosed by Wloczysiak & Nagayama, such that it is adapted to provide a high impedance state for signals within the band of other signal path, in this case the first frequency band B7, for the advantage of filtering out the unwanted frequency band (i.e.B7). Regarding claim 24, Wloczysiak & Nagayama disclose as cited in claim 21. Wloczysiak further discloses the radio frequency front-end circuit further comprises: the first filter and a first phase shifter 138, wherein the first phase shifter is coupled between the first output end and the first filter, wherein the first phase shifter is configured to perform phase-shifting on the second frequency band signal and the third frequency band signal (See fig. 12G). However, they do not mention that after phase-shifting, impedances of frequency ranges of the second frequency band signal and the third frequency band signal are in a high impedance state in the first filter. Since Balm teaches a front-end for CA mode, wherein a phase shifter is adapted to provide a high impedance state for signals within the band of other signal path (See fig. 1 and col. 2 lines 11-18); therefore, it would have been obvious to one skilled in the art to apply the teaching of Balm in modifying the phase-shifter 138, as disclosed by Wloczysiak & Nagayama, such that it is adapted to provide a high impedance state for signals within the band of other signal path, in this case the second and third frequency bands (i.e. B1/B3 and B32), for the advantage of filtering out the unwanted frequency band (i.e.B1/B3 and B32). Regarding claim 26, Wloczysiak & Nagayama disclose as cited in claim 25. Wloczysiak further discloses the radio frequency front-end circuit further comprises: a second phase shifter 134, wherein the second phase shifter is coupled between the third filter and the third output end corresponding to the third filter, wherein the second phase shifter is configured to perform phase-shifting on the second frequency band signal, and wherein the frequency range of the second frequency band signal (i.e. MB) is between the frequency range of the first frequency band signal (i.e. HB) and the frequency range of the third frequency band signal (i.e. MLB) (See fig. 12G). However, they do not mention that after phase-shifting, impedance of a frequency range of the second frequency band signal is in a high impedance state in the third filter. Since Balm teaches a front-end for CA mode, wherein a phase shifter is adapted to provide a high impedance state for signals within the band of other signal path (See fig. 1 and col. 2 lines 11-18); therefore, it would have been obvious to one skilled in the art to apply the teaching of Balm in modifying the phase-shifter 134, as disclosed by Wloczysiak & Nagayama, such that it is adapted to provide a high impedance state for signals within the band of other signal path, in this case the second frequency band B1/B3, for the advantage of filtering out the unwanted frequency band (i.e.B1/B3). Regarding claim 33, Wloczysiak & Nagayama disclose as cited in claim 32. However, they do not mention that after phase-shifting, an impedance of a frequency range of the first frequency band signal is in a high impedance state in the phase-shift filter. Since Balm teaches a front-end for CA mode, wherein a phase shifter is adapted to provide a high impedance state for signals within the band of other signal path (See fig. 1 and col. 2 lines 11-18); therefore, it would have been obvious to one skilled in the art to apply the teaching of Balm in modifying the phase-shift filter 142, as disclosed by Wloczysiak & Nagayama, such that it is adapted to provide a high impedance state for signals within the band of other signal path, in this case the first frequency band B7, for the advantage of filtering out the unwanted frequency band (i.e.B7). Regarding claim 34, Wloczysiak & Nagayama disclose as cited in claim 31. Wloczysiak further discloses the radio frequency front-end circuit further comprises: the first filter and a first phase shifter 138, wherein the first phase shifter is coupled between the first input end and the first filter, wherein the first phase shifter is configured to perform phase-shifting on the second frequency band signal and the third frequency band signal (See fig. 12G). However, they do not mention that after phase-shifting, impedances of frequency ranges of the second frequency band signal and the third frequency band signal are in a high impedance state in the first filter. Since Balm teaches a front-end for CA mode, wherein a phase shifter is adapted to provide a high impedance state for signals within the band of other signal path (See fig. 1 and col. 2 lines 11-18); therefore, it would have been obvious to one skilled in the art to apply the teaching of Balm in modifying the phase-shifter 138, as disclosed by Wloczysiak & Nagayama, such that it is adapted to provide a high impedance state for signals within the band of other signal path, in this case the second and third frequency bands (i.e. B1/B3 and B32), for the advantage of filtering out the unwanted frequency band (i.e.B1/B3 and B32). Regarding claim 36, Wloczysiak & Nagayama disclose as cited in claim 35. Wloczysiak further discloses the radio frequency front-end circuit further comprises: a second phase shifter 134, wherein the second phase shifter is coupled between the third filter and a second input end corresponding to the third filter, wherein the second phase shifter is configured to perform phase-shifting on the second frequency band signal, and wherein the frequency range of the second frequency band signal (i.e. MB) is between the frequency range of the first frequency band signal (i.e. HB) and the frequency range of the third frequency band signal (i.e. MLB) (See fig. 12G). However, they do not mention that after phase-shifting, impedance of a frequency range of the second frequency band signal is in a high impedance state in the third filter. Since Balm teaches a front-end for CA mode, wherein a phase shifter is adapted to provide a high impedance state for signals within the band of other signal path (See fig. 1 and col. 2 lines 11-18); therefore, it would have been obvious to one skilled in the art to apply the teaching of Balm in modifying the phase-shifter 134, as disclosed by Wloczysiak & Nagayama, such that it is adapted to provide a high impedance state for signals within the band of other signal path, in this case the second frequency band B1/B3, for the advantage of filtering out the unwanted frequency band (i.e.B1/B3). Allowable Subject Matter Claims 27-30 and 37-39 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. Regarding claim 27, Wloczysiak & Nagayama disclose as cited in claim 21. However, they do not mention that the second filter and the third filter are coupled to a same third output end, the second filter and the third filter are two filters in a multiplexer. Regarding claims 28-30, Wloczysiak & Nagayama disclose as cited in claim 21. However, they do not mention that the phase- shift filter comprises a function of a phase shifter and a function of a low-pass filter, wherein the phase-shift filter comprises a first inductor, a second inductor, a third inductor, and a capacitor, wherein a first end of the first inductor is coupled to the second output end, wherein a second end of the first inductor is coupled to a first end of the second inductor, wherein a second end of the second inductor is coupled to a first input end of the second switch group, wherein a first end of the capacitor is coupled between the first inductor and the second inductor, and wherein a second end of the capacitor is connected in series to the third inductor. Regarding claim 37, Wloczysiak & Nagayama disclose as cited in claim 31. However, they do not mention that the second filter and the third filter are coupled to a same second input end, the second filter and the third filter are two filters in a multiplexer. Regarding claims 38-39, Wloczysiak & Nagayama disclose as cited in claim 31. However, they do not mention that the phase- shift filter comprises a function of a phase shifter and a function of a low-pass filter, wherein the phase-shift filter comprises a first inductor, a second inductor, a third inductor, and a capacitor, wherein a first end of the first inductor is coupled to the third input end, wherein a second end of the first inductor is coupled to a first end of the second inductor, wherein a second end of the second inductor is coupled to a first output end of the second switch group, wherein a first end of the capacitor is coupled between the first inductor and the second inductor, and wherein a second end of the capacitor is connected in series to the third inductor. The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. See PTO-892 for a listing of cited prior arts of record. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to TUAN A TRAN whose telephone number is (571)272-7858. The examiner can normally be reached Mon-Fri: 7:30 AM - 5:00 PM. 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, Wesley Kim can be reached at (571) 272-7867. 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. /TUAN A TRAN/Primary Examiner, Art Unit 2648
Read full office action

Prosecution Timeline

Mar 28, 2024
Application Filed
Mar 07, 2026
Non-Final Rejection — §103 (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
85%
Grant Probability
92%
With Interview (+7.4%)
2y 7m
Median Time to Grant
Low
PTA Risk
Based on 774 resolved cases by this examiner. Grant probability derived from career allow rate.

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