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 .
Response to Amendment
The Amendment filed November 26, 2025 has been entered. Claims 1 and 4-14 remain pending in the application.
Response to Arguments
Applicant’s arguments, see pages 4-5, filed November 26, 2025, with respect to the rejections of claims 1 and 4-14 under 35 U.S.C. § 103 have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of previously presented prior art reference Soga (Patent Publication Number US 2021/0126586 A1), as cited by applicant, hereafter referred to as Soga.
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, 4-6, 10-11, and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Soga in view of Nielsen (Patent Publication Number US 2020/0350876 A1) hereafter referred to as Nielsen.
Regarding claim 1, Soga discloses:
A circuit (Soga, Fig. 1) comprising: a power amplifier cell (Fig. 1, 50) comprising a bipolar junction transistor (BJT) (Fig. 1, Q10) comprising an input node (Fig. 1, 51) configured to receive a signal input (Paragraph 19, line 9), the input node coupled to a base of the BJT (Fig. 1, see connection between 51 and B10); a ballast resistor (Fig. 1, R9) coupled to the base of the BJT (Fig. 1, see connection between R9 and B10) electrically in parallel with the input node (Fig. 1, see parallel connection of 51 and R9) and without passing through the input node (Fig. 1, see connection of R9 to B10 without passing through 51): and a bias circuit (Fig. 1, 10) comprising: an input (Fig. 1, Vbatt); a first transistor (Fig. 1, Q3), a second transistor (Fig. 1, Q1), and a third transistor (Fig. 1, Q2), a first collector of the first transistor coupled to the input (Fig. 1, see connection between C3 and Vbatt); an output (Fig. 1, see connection between 10 and R9) coupled to the power amplifier cell through the ballast resistor (Fig. 1, see connection between 10 and Q10 via R9), the bias circuit configured to provide a bias signal to the power amplifier cell through the ballast resistor (Fig. 1, see connection between 10 and Q10 via R9); and a feedback network (Fig. 1, R7) comprising an impedance (Fig. 1, R7) and coupling a first emitter of the first transistor to: a second base of the second transistor (Fig. 1, see connection between E3 and B1 via R7) and a third base of the third transistor (Fig. 1, see connection between E3 and B2 via R7), wherein the second base is directly coupled to the third base (Fig. 1, see direction connection between B1 and B2), the feedback network configured to, in combination with the ballast resistor, provide a ballast resistance to the bias signal (Paragraph 39, lines 10-14), but fails to disclose [the ballast resistance to the bias signal] under three hundred ohms (300 Ω).
However, Nielsen teaches [the ballast resistance to the bias signal] under three hundred ohms (300 Ω) (Nielsen, Fig. 4, Element 68 [ballast resistor] and Element 36 [feedback network] combine to provide 82 Ω of resistance).
Soga and Nielsen are both considered to be analogous to the claimed invention because they are in the same field of improving power amplifiers used in radio frequency communications. Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have modified Soga to incorporate the teachings of Nielsen to modify the feedback and ballast resistors of Soga to provide a combined resistance of less than 300 Ω, which would have the effect of improving linearity of the amplifier system (Nielsen, Page 1, Paragraph 4, lines 1-5).
Regarding claim 4, Soga fails to disclose:
wherein the ballast resistor is less than 150 Ω.
However, Nielsen further teaches wherein the ballast resistor is less than 150 Ω (Nielsen, Fig. 4, Element 68 is 7 Ω ballast resistor).
Soga and Nielsen are both considered to be analogous to the claimed invention because they are in the same field of improving power amplifiers used in radio frequency communications. Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have modified Soga to incorporate the teachings of Nielsen to modify the ballast resistor of Soga to provide a ballast resistance of 7 Ω, which would have the effect of improving linearity of the amplifier system (Nielsen, Page 1, Paragraph 4, lines 1-5).
Regarding claim 5, Soga fails to disclose:
wherein the ballast resistor is less than approximately 50 Ω.
However, Nielsen further teaches wherein the ballast resistor is less than approximately 50 Ω (Nielsen, Fig. 4, Element 68 is 7 Ω ballast resistor).
Soga and Nielsen are both considered to be analogous to the claimed invention because they are in the same field of improving power amplifiers used in radio frequency communications. Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have modified Soga to incorporate the teachings of Nielsen to modify the ballast resistor of Soga to provide a ballast resistance of 7 Ω, which would have the effect of improving linearity of the amplifier system (Nielsen, Page 1, Paragraph 4, lines 1-5).
Regarding claim 6, Soga further discloses:
further comprising a capacitor (Soga, Fig. 1, C20) coupled to the input node of the power amplifier cell (Fig. 1, see connection between C20 and 51) and configured to receive a radio frequency (RF) input signal (Fig. 1, Paragraph 19, lines 10-13).
Regarding claim 10, Soga further discloses:
wherein the first, second, and third transistors of the bias circuit form a Wilson current mirror (Soga, Fig. 1, see that Q3, Q1, and Q2 form a Wilson current mirror).
Regarding claim 11, Soga further discloses:
wherein the first, second, and third transistors of the bias circuit form a Widlar current mirror (Soga, Fig. 1, consider that transistors Q3 and Q4, and resistors R8 and R7, form a Widlar current mirror).
Regarding claim 13, Soga further discloses:
wherein the feedback network comprises a first resistor (Soga, Fig. 1, R7) serially coupled to the ballast resistor (Fig. 1, see connection between R7 and R9).
Claims 7, 9, and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Soga in view of Nielsen as applied to claim 1 above, and further in view of Sasaki et al. (Patent Publication Number JP 2020/048184 A), hereafter referred to as Sasaki.
Regarding claim 7, Soga and Nielsen fail to disclose:
wherein the bias circuit is coupled to a power amplifier stack and the power amplifier cell is one of a plurality of power amplifier cells within the power amplifier stack.
However, Sasaki teaches wherein the bias circuit is coupled to a power amplifier stack (Sasaki, Fig. 8, see stack of power amplifier cells 42 and Page 2, 3rd Paragraph from bottom, lines 3-4) and the power amplifier cell is one of a plurality of power amplifier cells within the power amplifier stack (Fig. 8, see top power amplifier cell 42).
Soga, Nielsen, and Sasaki are all considered to be analogous to the claimed invention because they are in the same field of improving power amplifiers used in radio frequency communications. Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have modified Soga to incorporate the teachings of Sasaki to include the power amplifier stack of Sasaki in the circuit of Soga, which would have the effect of increasing the output power of the circuit of Soga (Sasaki, Page 2, Paragraph 6, lines 1-6).
Regarding claim 9, Soga and Nielsen fail to disclose:
wherein the power amplifier stack comprises a single-ended output.
However, Sasaki further teaches wherein the power amplifier stack comprises a single-ended output (Sasaki, Fig. 8, see single-ended output at collectors of power amplifiers 42).
Soga, Nielsen, and Sasaki are all considered to be analogous to the claimed invention because they are in the same field of improving power amplifiers used in radio frequency communications. Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have modified Soga to incorporate the teachings of Sasaki to include the power amplifier stack of Sasaki in the circuit of Soga, which would have the effect of increasing the output power of the circuit of Soga (Sasaki, Page 2, Paragraph 6, lines 1-6).
Regarding claim 14, Soga fails to disclose:
wherein the feedback network comprises a loop gain and impedance seen by the bias signal is based on the loop gain.
However, Sasaki further teaches wherein the feedback network comprises a loop gain (Sasaki, Fig. 8, see R5 and loop via transistors Q3 and Q2) and impedance seen by the bias signal is based on the loop gain (Page 8, 2nd Paragraph from bottom, lines 4-6).
Soga, Nielsen, and Sasaki are all considered to be analogous to the claimed invention because they are in the same field of improving power amplifiers used in radio frequency communications. Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have modified Soga to incorporate the teachings of Sasaki to include the feedback network of Sasaki in the circuit of Soga, which would have the effect of providing high quality temperature control (Sasaki, Page 5, Paragraph 7, lines 1-7 and Page 9, Paragraph 1, lines 4-5).
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Soga in view of Nielsen and Sasaki as applied to claim 7 above, and further in view of Nobbe et al. (Patent Number US 9,287,829 B2) hereafter referred to as Nobbe.
Regarding claim 8, Soga, Nielsen, and Sasaki all fail to disclose wherein the power amplifier stack comprises a differential output.
However, Nobbe teaches wherein the power amplifier stack comprises a differential output (Nobbe, Fig. 18, see RFout+ and RFout-).
Soga, Nielsen, Sasaki, and Nobbe are all considered to be analogous to the claimed invention because they are in the same field of improving power amplifiers used in radio frequency communications. Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have modified Soga to incorporate the teachings of Nobbe to modify the amplifier stack of Soga to replace the single-ended output with a differential output, which would have the effect of enabling an even higher output power (Nobbe, Col. 17, lines 22-27).
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Soga in view of Nielsen as applied to claim 1 above, and further in view of Ning et al. (Patent Number CN 204,272,038 U) hereafter referred to as Ning.
Regarding claim 12, Soga and Nielsen fail to disclose wherein the feedback network comprises a T-shaped impedance circuit.
However, Ning teaches wherein the feedback network comprises a T-shaped impedance circuit (Ning, Fig. 1, Elements R1, R2, and R3).
Soga, Nielsen, and Ning are all considered to be analogous to the claimed invention because they are in the same field of improving power amplifiers used in radio frequency communications. Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have modified Soga to incorporate the teachings of Ning to modify the feedback network of Soga to include a T-shaped impedance circuit, which would have the effect of including more resistors in the circuit, which enables each resistor to be smaller, which reduces temperature drift error (Ning, Paragraph 12, lines 1-4).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Wang (Patent Number CN 2,785,256 Y) discloses (Fig. 2) a power amplifier with a bias circuit containing a Widlar current mirror.
Järvinen et al. (NPL Article) discloses (Fig. 1) a power amplifier with a T-shaped feedback network.
Chang et al. (NPL Article) discloses (Fig. 2) a power amplifier with a bias circuit containing a Wilson current mirror.
Joly et al. (Patent Publication Number JP 2004/537212 A) discloses (Fig. 12) a power amplifier with a T-shaped feedback network.
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 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.
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/LANCE TORBJORN BARTOL/Examiner, Art Unit 2843
/ANDREA LINDGREN BALTZELL/Supervisory Patent Examiner, Art Unit 2843