DETAILED ACTION
Response to Amendment
The applicant’s amendment filed 4/15/2026 has been entered. The applicant has amended claims 1, 11, 13, cancelled claims 18-20, and added claims 21-23. Claims 1-17 and 21-23 remain pending in the application. Applicant’s amendment of claim 11 has overcome the drawings objections and the 112(a) rejection of claim 11 set forth in the Non-Final Office Action mailed 1/15/2026 (“FAOM”), which are hereby withdrawn.
Response to Argument
Applicant's arguments, see pages 8-12 of the Remarks filed 4/15/2026 (“Remarks”), with respect to the remaining rejections of record have been fully considered but found not persuasive. The rejections of claims 1-17 are maintained and the newly added claims 21-23 are also rejected, as set forth below.
Regarding the 112(b) rejection of claims 1-12 and 17 (FAOM at 4), the applicant argues (Remarks at 9):
Claims 1-12 and 17 have been amended to particularly point out and distinctly claim the subject matter so that those having ordinary skill in the art understand the subject matter thereof with reasonable certainty. Accordingly, this rejection should be withdrawn.
The examiner respectfully disagrees. Contrary to the above statement, the applicant has not amended claim 17, which depends on claim 13 and still recites “a size of the quadrature coupler.” The rejection of claim 17 is therefore maintained, as set forth in the FAOM at 4. Regarding claims 1-12, the applicant has amended the limitation “a size of the quadrature coupler” in claim 1 to recite “a dimensional size value of the quadrature coupler” (emphasis added). However, the newly added terms still fail to identify any particular dimension(s), size(s) or value(s) of the quadrature coupler, which renders the claim indefinite (FAOM at 4).
To elaborate, there are at least two distinct meanings possible. First, “a dimensional size value of the quadrature coupler, i.e., the first slot width, the first slot length, the second slot width, and the second slot length, determine radio frequency characteristics of the quadrature coupler.” Second, “a dimensional size value of the quadrature coupler, and the first slot width, and the first slot length, and the second slot width, and the second slot length, determine radio frequency characteristics of the quadrature coupler.” In the first case, the applicant could amend the claims to recite “a dimensional size value of the quadrature coupler comprising the first slot width, the first slot length, the second slot width and the second slot length, determine radio frequency characteristics of the quadrature coupler.” In the second case, the applicant could amend the claims by identifying a dimensional size of a particular component(s) of the quadrature coupler. For example, the dimensions of the metallic upper plane 106 or the dimensions of the microstrip lines 104. Otherwise, “dimensional size value of the quadrature coupler” recited in claims 1 and 21 and “size of the quadrature coupler” recited in claims 9 and 17 are ambiguous and must be specified for specific component(s) of the quadrature coupler.
For the foregoing reasons, the 112(b) rejection of claims 1-12 is maintained. The new claims 21-23 also recite “a dimensional size value of the quadrature coupler” and are similarly rejected under 35 U.S.C. §112(b), as set forth below.
Regarding the 102 rejection of claims 1 and 13 (FAOM at 5-8), the applicant argues (Remarks at 9-10):
Sun et al. does not disclose, teach, or suggest: a second slot in the metallic upper plane having a second slot width and a second slot length, wherein the first slot crosses the second slot at an intersection point, and wherein the first slot formed in the metallic upper plane and the second slot formed in the metallic upper plane comprise a non-metallic opening in the metallic upper plane, as recited in amended independent claim 1.
Sun et al. however does not disclose, teach, or suggest: an opening in the upper metallic plane portion comprising a first slot and a second slot, wherein the first slot and the second slot form a cross-shaped pattern that intersects at an intersection point, and wherein the cross-shaped pattern that intersects at the intersection point is non-metallic, as recited in amended independent claim 13.
The examiner respectfully disagrees. As set forth in the FAOM at 5-8 and below, Sun discloses a quadrature hybrid coupler fabricated on Rogers RT/Duroid 6010 metalized dielectric substrate (Sun at 1431, FAOM at 7). Regarding the newly added “non-metallic opening in the metallic upper plane” and “the cross-shaped pattern that intersects at the intersection point is non-metallic” limitations, Sun explicitly teaches that the “coupler is obtained by etching out the cross slots with varied width or length on the squared patch” (Sun at 1427). Sun therefore discloses that the “openings” and “cross-shaped patterns” obtained after the metalized portions are etched out are “non-metallic,” as recited in the amended claims 1 and 13.
Regarding the 102 rejection of claims 2-9 and 14-17, which are dependent on claims 1 and 13, respectively, the applicant does not make any additional arguments.
Regarding the 103 rejection of claims 10 and 12 (FAOM at 9-10), the applicant relies on the same argument as above.
For the foregoing reasons, the 102 rejection of claims 1-9 and 13-17, and the 103 rejection of claims 10 and 12 are maintained, as set forth below.
Claim Rejections - 35 USC § 112
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1-12, 17, 21-23 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor, or a joint inventor, regards as the invention.
Claims 1 and 21 recite “a dimensional size value of the quadrature coupler.” It is unclear what particular dimension(s), size(s) or value(s) the term refers to, which renders the claim indefinite. The term is not defined by the claim, is not described or even mentioned in the disclosure, and is not well-known in the art. Therefore, one of ordinary skill in the art would not be reasonably apprised of the scope of the invention.
Claim 17 recites “a size of the quadrature coupler determines a center frequency of the quadrature coupler.” It is unclear what particular dimension(s) or size(s) the term refers to, which renders the claim indefinite. The term is not defined by the claim, the specification does not provide a standard for ascertaining the dimension(s) and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention.
For examination purposes, these terms will be understood to refer to the overall size, that is, the length and width, of the metallic upper plane.
Claims 2-12 and 22-23 are also rejected under 35 U.S.C. 112(b) as dependent on the rejected claim(s).
Claim 9 is additionally rejected under 35 U.S.C. 112(b) because there is now insufficient antecedent basis for the limitation “the size of the quadrature coupler.” For examination purposes, this limitation will be understood to refer to the “dimensional size value of the quadrature coupler” recited in the amended claim 1.
Claims 21-23 are additionally rejected under 35 U.S.C. 112(b) because claim 21 recites “a first surround around the first slot, and a second surround around the second slot.” It is unclear what is meant by “first surround” and “second surround” because the terms are not defined by the claim, are not even mentioned in the disclosure as filed and are not well-known in the art. Therefore, one of ordinary skill in the art would not be reasonably apprised of the scope of the invention.
For examination purposes, the terms “first surround” and “second surround” will be understood to mean the metallic upper plane surrounding the slots.
Appropriate correction is required.
Claim Rejections - 35 USC § 102
Claims 1-9, 13-17, and 21-23 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by S. Sun and L. Zhu, Miniaturised patch hybrid couplers using asymmetrically loaded cross slots, IET Microw. Antennas Propag., 2010, Vol. 4, Iss. 9, pp. 1427 –1433 (“Sun”).
Sun discloses in Figs. 1-3, Tables 1-2, pp. 1427 –1433:
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Claims 1, 13-14 and 21 (as best understood)
A quadrature coupler (Figs. 1-3, pp. 1427 –1433), comprising:
a top metallization layer, comprising:
a metallic upper plane (Fig. 1b, annotated),
a first port (#1) coupled to the metallic upper plane via a first microstrip line, a second port (#2) coupled to the metallic upper plane via a second microstrip line, a third port (#3) coupled to the metallic upper plane via a third microstrip line, and a fourth port (#4) coupled to the metallic upper plane via a fourth microstrip line, wherein the first port is opposite the third port, the first port is adjacent to the second port, and the first port is the adjacent to fourth port (Fig. 1b),
a first slot in the metallic upper plane having a first slot width (W1) and a first slot length (L1),
a second slot in the metallic upper plane having a second slot width (W2) and a second slot length (L2), wherein the first slot crosses the second slot at an intersection point (Fig. 1b, annotated), and
wherein the first slot formed in the metallic upper plane and the second slot formed in the metallic upper plane comprise a non-metallic opening in the metallic upper plane (Sun discloses a quadrature hybrid coupler fabricated on Rogers RT/Duroid 6010 metalized dielectric substrate (p. 1431) and teaches that the “coupler is obtained by etching out the cross slots with varied width or length on the squared patch” (p. 1427). Sun therefore discloses that the “openings” and “cross-shaped patterns” obtained after the metalized portions are etched out are “non-metallic.”);
a bottom metallization layer comprising a ground plane (Sun discloses a microstrip coupler, which by definition would necessarily include a bottom metallization layer comprising a ground plane. See, e.g., The Authoritative Dictionary of IEEE Standards Terms, 7th Ed., 2000, pp. 693-4); and
a substrate (Fig. 1, “substrate: ε=10.8, thickness=0.635 mm”) between the top metallization layer and the bottom metallization layer,
wherein a dimensional size value of the quadrature coupler, the first slot width, the first slot length, the second slot width, and the second slot length, determine radio frequency characteristics of the quadrature coupler, the radio frequency characteristics comprising a defined bandwidth around a center frequency (Figs. 3b-c, Tables 1-2, illustrating how L1, L2, W1, and W2 determine radio frequency characteristics of the quadrature coupler).
Regarding claims 13 and 14, Sun teaches to use its quadrature hybrid couplers in various devices, including antenna arrays (p. 1427).
Regarding claim 21, Sun teaches “wherein the first port (#1), the second port (#2), the third port (#3), and the fourth port (#4) are formed as being flush with the metallic plane” and “wherein the first port, the first microstrip line, the second port, the second microstrip line, the third port, the third microstrip line, the fourth port, the fourth microstrip line, a first surround around the first slot, and a second surround around the second slot are formed flush with the metallic plane” (Sun discloses a quadrature hybrid coupler fabricated on Rogers RT/Duroid 6010 metalized dielectric substrate (p. 1431); Figs. 1b and 5a show that the first port, the first microstrip line, the second port, the second microstrip line, the third port, the third microstrip line, the fourth port, the fourth microstrip line, and the metal plane surrounding the slots are all formed from/in the upper metallic plane of the metalized dielectric substrate and therefore are flush with the metallic plane).
Claims 2 and 22
wherein the first slot is angled at substantially about forty-five degrees relative to the first microstrip line and the third microstrip line, and wherein the second slot is substantially perpendicular to the first slot (Fig. 1b, annotated).
Claims 3 and 23
wherein the first slot length is greater than the second slot length (Fig. 2, L1=7.6mm, L2=5.8mm).
Claims 4 and 15
wherein the metallic upper plane is substantially square, and wherein the intersection point of the first slot and the second slot is substantially centered relative to the metallic upper plane (Fig. 1b, annotated)..
Claim 5
wherein at least one of: the first slot width, the first slot length, the second slot width, or the second slot length, is defined at least in part based on a material of the substrate (Fig. 1, p. 1431, specifying the material of substrate as Rogers RT/Duroid 6010 LM with ε=10.8 and thickness=0.635 mm).
Claims 6 and 16
wherein at least one of: the first slot width, the first slot length, the second slot width, or the second slot length, is determined at least in part based on radio frequency matching of the quadrature coupler (Figs. 3b-c, Tables 1-2, pp. 1429-21, illustrating how L1, L2, W1, and W2 determine radio frequency characteristics of the quadrature coupler).
Claim 7
wherein scattering parameters of the quadrature coupler are determined at least in part by at least one of: the first slot width, the first slot length, the second slot width, or the second slot length (Figs. 3b-c, Tables 1-2, pp. 1429-21, illustrating how L1, L2, W1, and W2 determine scattering parameters of the quadrature coupler).
Claim 8
wherein the defined bandwidth of the quadrature coupler is determined at least in part by at least one of: the first slot width, the first slot length, the second slot width, or the second slot length (Figs. 2b-c, 3b-c illustrating how L1, L2, W1, and W2 determine the frequency bandwidth of the quadrature coupler).
Claims 9 and 17 (as best understood)
wherein the center frequency of the quadrature coupler is determined by the size of the quadrature coupler (p. 1429, teaching how to determine the overall size of the cross-slot patch based on the desired wavelength).
Claim 11
wherein the top metallization layer and the bottom metallization layer form a waveguide without an interconnecting layer between the top metallization layer and the bottom metallization layer (Sun discloses a quadrature hybrid coupler fabricated on Rogers RT/Duroid 6010 metalized dielectric substrate (p. 1431), which does not have any interconnecting layer between the top metallization layer and the bottom metallization layer).
Claim Rejections - 35 USC § 103
Claims 10 and 12 are rejected under 35 U.S.C. 103 as being unpatentable over Sun, taken alone.
Claim 10
As set forth above, Sun discloses all the limitations of claim 10 except wherein respective length and width dimensions of the first port, the second port, the third port, and the fourth port determine a characteristic impedance of the quadrature coupler.
It was well known in the art before the effective filing date of the claimed invention that the respective length and width dimensions of the microstrip lines functioning as the ports determine a characteristic impedance of the quadrature coupler. See, e.g., C. Free and C. Aitchison, RF and Microwave Circuit Design: Theory and Applications, Wiley 2022, pp. 53, 61-62.
It would therefore have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have respective length and width dimensions of the first port, the second port, the third port, and the fourth port determine a characteristic impedance of the quadrature coupler.
Claim 12
As set forth above, Sun discloses all the limitations of claim 12 except wherein the defined bandwidth is greater than around three gigahertz at a center frequency greater than around fifteen gigahertz.
However, Sun teaches that the center frequency and the bandwidth of its coupler depends on various variables, including the overall cross-slot patch size (metallic upper plane) and the lengths and widths of the slots (Fig. 3; pp. 1427-9). Specifically, Sun teaches that the overall cross-slot patch size defines the operating wavelength (p. 1429). Sun further teaches that the center frequency is increasing as the length of the slots is decreasing (p. 1429). Thus, the overall cross-slot patch size and the length of the slots are result-effective variables, i.e., the variables that achieves a recognized result. MPEP 2144.05(II)(A).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the overall cross-slot patch size and/or the length and width of the slots to define bandwidth greater than around three gigahertz at a center frequency greater than around fifteen gigahertz, as taught by Sun (Fig. 3; Table 1; pp. 1427-9)
In addition, the modification would have been obvious because the overall cross-slot patch size and the lengths and widths of the slots are design parameters that can be set as desired for controlling the bandwidth and the center frequency of the coupler, as taught by Sun (Fig. 3; Table 1; pp. 1427-9). The overall cross-slot patch size and the lengths and widths of the slots may be set (greater or different) as a result of optimization to achieve the desired characteristics as known in the art (MPEP 2144.05(II)(A)) and/or simply obvious to try as there are only limited choices of the relationships (greater, smaller, same, or different; MPEP 2143(I)(E)).
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to VICTOR COLE, telephone number (571) 272-4686. The examiner can be reached Monday-Friday, 9AM-5PM ET.
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 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.
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/VICTOR COLE/
Examiner, Art Unit 2843
/ANDREA LINDGREN BALTZELL/Supervisory Patent Examiner, Art Unit 2843
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