# US 12,603,614 B2 · Wideband doherty power amplifier > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,603,614 B2 - Document ID: US12603614B2 - Status: Granted - Kind: B2 - Application number: 18/063,699 - Filed: 2022-12-09 - Published: 2024-06-13 - Granted: 2026-04-14 - Earliest claimed: 2022-12-09 - Assignees: Silicon Laboratories Inc. - Applicants: Silicon Laboratories Inc. - Inventors: Aslamali A. Rafi - Web page: https://patentgrep.com/patent/US12603614B2 ## CPC - H03F 1/0288: {using a main and one or several auxiliary peaking amplifiers whereby the load is connected to the main amplifier using an impedance inverter, e.g. Doherty amplifiers} - H03F 1/0227: {using supply converters} - H03F 3/195: in integrated circuits - H03F 3/211: {using a combination of several amplifiers (H03F3/60 takes precedence)} - H03F 3/245: {with semiconductor devices only} - H04B 1/0458: {Arrangements for matching and coupling between power amplifier and antenna or between amplifying stages (matching circuits in general H03H)} - H03F 2200/451: the amplifier being a radio frequency amplifier - H03F 2200/541: Transformer coupled at the output of an amplifier - H04B 2001/0408: {with power amplifiers} - H03F: AMPLIFIERS - H04B: TRANSMISSION ## Abstract In on example, an apparatus includes: a first power amplifier (PA) to receive a first input radio frequency (RF) signal and output a first amplified RF signal; a second PA to receive a second input RF signal and output a second amplified RF signal; and a transformer circuit coupled to an output of the first PA and an output of the second PA. The transformer circuit is to provide, to a load circuit, an RF output signal comprising the first amplified RF signal and the second amplified RF signal. ## Claims ### Claim 1 An apparatus comprising: a first power amplifier (PA) to receive a supply voltage, a first input radio frequency (RF) signal and output a first amplified RF signal; a second PA to receive the supply voltage, a second input RF signal and output a second amplified RF signal; and a transformer circuit coupled to an output of the first PA and an output of the second PA, wherein the transformer circuit is to provide, to a load circuit, an RF output signal comprising the first amplified RF signal and the second amplified RF signal, wherein the transformer circuit comprises: a first transformer-capacitor circuit comprising: a first primary winding coupled to the output of the first PA and a first secondary winding inductively coupled to the first primary winding to provide the first amplified RF signal to the load circuit, the first primary winding coupled to a first center tap node to receive half the supply voltage; a first capacitor coupled in parallel with the first primary winding; and a second capacitor coupled in parallel with the first secondary winding, wherein the first transformer-capacitor circuit, via the first primary winding, the first secondary winding, the first capacitor and the second capacitor, implements a transmission line having a characteristic impedance of the load circuit; and a second transformer-capacitor circuit comprising: a second primary winding coupled to the output of the second PA and a second secondary winding inductively coupled to the second primary winding to provide the second amplified RF signal to the load circuit, the second primary winding coupled to a second center tap node to receive half the supply voltage; a third capacitor coupled in parallel with the second primary winding; a fourth capacitor coupled in parallel with the second secondary winding; a fifth capacitor coupled to the second secondary winding; and a sixth capacitor coupled to the second secondary winding. ### Claim 2 A transmitter comprising: a signal processing path comprising: a digital baseband circuit to process data and output digital data; a converter to convert the digital data to analog data; at least one complex mixer to upconvert the analog data to quadrature radio frequency (RF) signals; a first power amplifier (PA) to receive a supply voltage and coupled to the at least one complex mixer to receive a first quadrature RF signal and output a first amplified quadrature RF signal; a second PA to receive the supply voltage and coupled to the at least one complex mixer to receive a second quadrature RF signal and output a second amplified quadrature RF signal; and a transformer circuit coupled to an output of the first PA and an output of the second PA, wherein the transformer circuit is to provide, to a load circuit, an RF output signal comprising the first amplified quadrature RF signal and the second amplified quadrature RF signal, wherein the transformer circuit comprises: a first transformer-capacitor circuit comprising: a first primary winding coupled to the output of the first PA and a first secondary winding inductively coupled to the first primary winding to provide the first amplified quadrature RF signal to the load circuit; a first capacitor coupled in parallel with the first primary winding; and a second capacitor coupled in parallel with the first secondary winding, wherein the first transformer-capacitor circuit, via the first primary winding, the first secondary winding, the first capacitor and the second capacitor, implements a transmission line having a characteristic impedance of the load circuit; and a second transformer-capacitor circuit comprising: a second primary winding coupled to the output of the second PA and a second secondary winding inductively coupled to the second primary winding to provide the second amplified quadrature RF signal to the load circuit; a third capacitor coupled in parallel with the second primary winding; a fourth capacitor coupled in parallel with the second secondary winding; a fifth capacitor coupled to the second secondary winding; and a sixth capacitor coupled to the second secondary winding. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein the transformer circuit comprises at least one planar transformer. ### Claim 4 (depends on 3) The apparatus of claim 3, wherein the at least one planar transformer comprises: a first winding having a proximal portion and a distal portion, the proximal portion adjacent an opening; a first conductor coupled to an interior of the proximal portion and to provide the first amplified RF signal; and a second conductor coupled to an exterior of the proximal portion and to provide the supply voltage. ### Claim 5 (depends on 4) The apparatus of claim 4, wherein the first conductor has a first width and the second conductor has a second width, the second width greater than the first width. ### Claim 6 (depends on 4) The apparatus of claim 4, wherein the supply voltage provided via the second conductor is less than a first supply voltage provided to the first PA. ### Claim 7 (depends on 1) The apparatus of claim 1, wherein the first PA comprises a main PA and the second PA comprises an auxiliary PA. ### Claim 8 (depends on 7) The apparatus of claim 7, wherein the main PA is to operate as a Class AB device and the auxiliary PA is to operate as a Class C device. ### Claim 9 (depends on 1) The apparatus of claim 1, wherein the transformer circuit comprises a 2:1 ratio between a primary side and a secondary side, the transformer circuit comprising a quarter wavelength transmission line, the quarter wavelength transmission line comprising a matched transmission line. ### Claim 10 (depends on 9) The apparatus of claim 9, wherein the first PA and the second PA are to operate over a wideband comprising at least 2.0 gigahertz. ### Claim 11 (depends on 9) The apparatus of claim 9, wherein the quarter wavelength transmission line has a 1× impedance transformation in a backoff region. ### Claim 12 (depends on 1) The apparatus of claim 1, wherein: the first PA is to output a first output current that varies based on an input voltage according to a first slope; and the second PA is to output a second output current that varies based on the input voltage according to a second slope, the second slope different than the first slope. ### Claim 13 (depends on 12) The apparatus of claim 12, wherein, via the transformer circuit, the load circuit is to receive the first output current and a transformed second output current that varies based on the input voltage according to the first slope and the second slope respectively. ### Claim 14 (depends on 1) The apparatus of claim 1, further comprising a dynamic bias circuit to provide a dynamic bias voltage to the second PA, based at least in part on an output voltage of the first PA. ### Claim 15 (depends on 1) The apparatus of claim 1, further comprising a scaling circuit to scale an input to at least one of the first PA or the second PA. ### Claim 16 A method comprising: amplifying, in a first power amplifier (PA) that receives a supply voltage, a first differential radio frequency (RF) signal and outputting a first amplified differential RF signal; amplifying, in a second PA that receives the supply voltage, a second differential RF signal and outputting a second amplified differential RF signal; transforming, in a first transformer coupled to the first PA, the first amplified differential RF signal to provide a first output RF signal to a load circuit, the first transformer comprising a matched transmission line and a first primary winding coupled to a first center tap node to receive half the supply voltage, the first primary winding coupled to an output of the first PA and a first secondary winding inductively coupled to the first primary winding to provide the first output RF signal to the load circuit, wherein a first capacitor is coupled in parallel with the first primary winding and a second capacitor is coupled in parallel with the first secondary winding to form the matched transmission line; and transforming, in a second transformer coupled to the second PA, the second amplified differential RF signal to provide a second output RF signal to the load circuit, the second transformer comprising a second primary winding coupled to a second center tap node to receive half the supply voltage, the second primary winding coupled to an output of the second PA and a second secondary winding inductively coupled to the second primary winding to provide the second output RF signal to the load circuit, wherein a third capacitor is coupled in parallel with the second primary winding, a fourth capacitor is coupled in parallel with the second secondary winding, a fifth capacitor is coupled between the second secondary winding and the load circuit, and a sixth capacitor is coupled between the second secondary winding and the load circuit. ### Claim 17 (depends on 16) The method of claim 16, further comprising dynamically biasing the second PA based at least in part on the first differential RF signal. ### Claim 18 (depends on 16) The method of claim 16, further comprising amplifying, in the first PA and the second PA, a plurality of differential RF signals over a bandwidth of at least 2.0 gigahertz.