# US 2019/0356284 A1 · Broadband power transistor devices and amplifiers and methods of manufacture thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0356284 A1 - Document ID: US20190356284A1 - Status: Published application - Kind: A1 - Application number: 15/983,974 - Filed: 2018-05-18 - Published: 2019-11-21 - Earliest claimed: 2018-05-18 - Assignees: NXP USA, Inc. - Applicants: NXP USA, Inc. - Inventors: Ning ZHU; Damon G. HOLMES; Jeffrey Spencer ROBERTS - Web page: https://patentgrep.com/patent/US20190356284A1 ## CPC - H03F 3/193: with field-effect devices (H03F3/195 takes precedence) - 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 1/565: {using inductive elements} - H03F 3/195: in integrated circuits - H03F 3/21: with semiconductor devices only {(H03F3/245 takes precedence)} - H03F 3/245: {with semiconductor devices only} - H10W 44/20: at high-frequency [HF] or radio frequency [RF] - H03F 2200/181: A coil being added in the gate circuit of a FET amplifier stage, e.g. for noise reducing purposes - H03F 2200/222: A circuit being added at the input of an amplifier to adapt the input impedance of the amplifier - H03F 2200/387: A circuit being added at the output of an amplifier to adapt the output impedance of the amplifier - H10W 44/234: {Arrangements for impedance matching} - H03F: AMPLIFIERS - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 ## Abstract Embodiments of RF amplifiers and packaged RF amplifier devices each include a transistor with a drain-source capacitance that is relatively low, an output impedance matching circuit, and a harmonic termination circuit. The impedance matching circuit includes a harmonic termination circuit, which includes a first inductance (a first plurality of bondwires) and a first capacitance coupled in series between the transistor output and a ground reference node. An equivalent capacitance from a combination of the first inductive element and the first capacitance in series effectively increases the drain-source capacitance by at least 10 percent. The impedance matching circuit also includes a second inductance (a second plurality of bondwires) and a second capacitance coupled in series between the transistor output and the ground reference node, where the second inductance and the second capacitance are directly connected. The first and second capacitances may be metal-insulator-metal capacitors in an integrated passive device. ## Claims ### Claim 1 A radio frequency (RF) amplifier with a first amplification path that comprises: a transistor die with a transistor and a transistor output terminal, wherein the transistor has a drain-source capacitance below 0.2 picofarads per watt; and an impedance matching circuit coupled between the transistor output terminal and an output of the first amplification path, wherein the impedance matching circuit includes a harmonic termination circuit comprising a first inductive element and a first capacitance connected in series between the transistor output terminal and a ground reference node, wherein an equivalent capacitance from a combination of the first inductive element and the first capacitance in series effectively increases the drain-source capacitance by at least 10 percent, the first inductive element includes a first plurality of bondwires with first ends connected to the output terminal of the transistor die and second ends connected to a first bond pad that is coupled to the first capacitance, and the harmonic termination circuit resonates at a harmonic frequency of a fundamental frequency of operation of the RF amplifier, and a second inductive element and a second capacitance connected in series between the transistor output terminal and the ground reference node, wherein the second inductive element includes a second plurality of bondwires with first ends connected to the output terminal of the transistor die and second ends connected to a second bond pad that is coupled to the second capacitance, and wherein the second plurality of bondwires and the second capacitance are directly connected. ### Claim 2 (depends on 1) The RF amplifier of claim 1, wherein the transistor is a gallium nitride transistor. ### Claim 3 (depends on 1) The RF amplifier of claim 1, wherein the first and second capacitors are metal-insulator-metal capacitors. ### Claim 4 (depends on 1) The RF amplifier of claim 1, wherein in the harmonic termination circuit, the first inductive element is directly connected to the first capacitance. ### Claim 5 (depends on 1) The RF amplifier of claim 1, wherein the harmonic termination circuit resonates at a second harmonic frequency of the fundamental frequency of operation. ### Claim 6 (depends on 1) The RF amplifier of claim 1, wherein: the first capacitance value is in a range of 1 picofarad to 100 picofarads; the second capacitor has a second capacitance value in a range of 30 picofarads to 500 picofarads; the first inductive element has an inductance value in a range of 20 picohenries to 1 nanohenry; and the second inductive element has an inductance value in a range of 100 picohenries to 3 nanohenries. ### Claim 7 (depends on 1) The RF amplifier of claim 1, further comprising: a video bandwidth circuit coupled to a connection node between the second inductive element and the second capacitance, wherein the video bandwidth circuit includes a plurality of components, wherein the plurality of components includes an envelope resistor, an envelope inductor, and an envelope capacitor coupled in series between the connection node and the ground reference node. ### Claim 8 (depends on 7) The RF amplifier of claim 7, wherein the video bandwidth circuit further includes a bypass capacitor coupled in parallel across one or more of the plurality of components of the video bandwidth circuit. ### Claim 9 (depends on 8) The RF amplifier of claim 8, wherein the bypass capacitor is coupled in parallel across the envelope inductor, and wherein the envelope inductor and the bypass capacitor form a parallel resonant circuit in proximity to a center operating frequency of the RF amplifier. ### Claim 10 (depends on 1) The RF amplifier of claim 1, further comprising: a second amplification path; a power divider with an input configured to receive an RF signal, a first output coupled to an input of the first amplification path, and a second output coupled to an input of the second amplification path, wherein the power divider is configured to divide the RF signal into a first RF signal that is provided to the first amplification path through the first output, and into a second RF signal that is provided to the second amplification path through the second output; and a combining node configured to receive and combine amplified RF signals produced by the first and second amplification paths. ### Claim 11 (depends on 10) The RF amplifier of claim 10, wherein the RF amplifier is a Doherty power amplifier. ### Claim 12 A packaged radio frequency (RF) amplifier device comprising: a device substrate; a first input lead coupled to the device substrate; a first output lead coupled to the device substrate; a first transistor die coupled to the device substrate, wherein the first transistor die includes a first transistor, a transistor input terminal coupled to the first input lead, and a transistor output terminal coupled to the first output lead, and wherein the first transistor has a drain-source capacitance below 0.2 picofarads per watt; a first integrated passive device coupled to the device substrate; and an impedance matching circuit coupled between the transistor output terminal and the first output lead, wherein the impedance matching circuit includes a harmonic termination circuit comprising a first inductive element and a first capacitance connected in series between the transistor output terminal and a ground reference node, wherein an equivalent capacitance from a combination of the first inductive element and the first capacitance in series effectively increases the drain-source capacitance by at least 10 percent, the first inductive element includes a first plurality of bondwires with first ends connected to the first transistor die and second ends connected to the first integrated passive device, and the harmonic termination circuit resonates at a harmonic frequency of a fundamental frequency of operation of the RF amplifier device, and a second inductive element and a second capacitance connected in series between the transistor output terminal and the ground reference node, wherein the second inductive element includes a second plurality of bondwires with first ends connected to the output terminal of the transistor die and second ends connected to the first integrated passive device, and wherein the second plurality of bondwires and the second capacitance are directly connected. ### Claim 13 (depends on 12) The packaged RF amplifier device of claim 12, wherein the second capacitance is integrally formed with the first integrated passive device. ### Claim 14 (depends on 13) The packaged RF amplifier device of claim 13, wherein the first and second capacitors are metal-insulator-metal capacitors. ### Claim 15 (depends on 12) The packaged RF amplifier device of claim 12, wherein the transistor is a gallium nitride transistor. ### Claim 16 (depends on 12) The packaged RF amplifier device of claim 12, wherein the harmonic termination circuit resonates at a second harmonic frequency of the fundamental frequency of operation. ### Claim 17 (depends on 12) The packaged RF amplifier device of claim 12, wherein: the first capacitance value is in a range of 1 picofarad to 100 picofarads; the second capacitor has a second capacitance value in a range of 30 picofarads to 500 picofarads; the first inductive element has an inductance value in a range of 20 picohenries to 1 nanohenry; and the second inductive element has an inductance value in a range of 100 picohenries to 3 nanohenries. ### Claim 18 (depends on 12) The packaged RF amplifier device of claim 12, further comprising: a video bandwidth circuit coupled to a connection node between the second inductive element and the second capacitance, wherein the video bandwidth circuit includes a plurality of components, wherein the plurality of components includes an envelope resistor, an envelope inductor, and an envelope capacitor coupled in series between the connection node and the ground reference node. ### Claim 19 (depends on 18) The packaged RF amplifier device of claim 18, wherein the video bandwidth circuit further includes a bypass capacitor coupled in parallel across one or more of the plurality of components of the video bandwidth circuit. ### Claim 20 (depends on 12) The packaged RF amplifier device of claim 12, further comprising: a second input lead coupled to the device substrate; a second output lead coupled to the device substrate; a second transistor die coupled to the device substrate, wherein the second transistor die includes a second transistor coupled between the second input lead and the second output lead; and a second integrated passive device coupled to the device substrate between the second transistor die and the second output. ### Claim 21 A method of manufacturing a radio frequency (RF) amplifier device, the method comprising the steps of: coupling an input lead to a device substrate; coupling an output lead to the device substrate; coupling a transistor die to the device substrate between the input and output leads, wherein the transistor die includes a transistor and a transistor output terminal, and wherein the transistor has a drain-source capacitance below 0.2 picofarads per watt; coupling an integrated passive device to the device substrate between the transistor die and the output lead, wherein the integrated passive device includes a first capacitance and a second capacitance, wherein the first capacitance includes one or more first capacitors that are integrally formed with the integrated passive device, and the second capacitance also is integrally formed with the integrated passive device; creating a harmonic termination circuit by connecting a first inductive element in the form of a first plurality of bondwires between the transistor output terminal and the first capacitance, wherein first ends of the first plurality of bondwires are connected to the transistor output terminal, and second ends of the first plurality of bondwires are connected to a first bond pad on the integrated passive device that is coupled to the first capacitance, and wherein an equivalent capacitance from a combination of the first inductive element and the first capacitance in series effectively increases the drain-source capacitance by at least 10 percent, and the harmonic termination circuit resonates at a harmonic frequency of a fundamental frequency of operation of the RF amplifier device; and creating a portion of an impedance matching circuit by connecting a second inductive element in the form of a second plurality of bondwires between the transistor output terminal and the second capacitance, wherein first ends of the second plurality of bondwires are connected to the transistor output terminal, and second ends of the second plurality of bondwires are connected to a second bond pad on the integrated passive device that is coupled to the second capacitance, and wherein the second plurality of bondwires and the second capacitance are directly connected.