# US 12,224,717 B2 · Distributed bias circuit for wideband amplifiers > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,224,717 B2 - Document ID: US12224717B2 - Status: Granted - Kind: B2 - Application number: 17/689,469 - Filed: 2022-03-08 - Published: 2023-09-14 - Granted: 2025-02-11 - Earliest claimed: 2022-03-08 - Assignees: Qorvo US, Inc. - Applicants: Qorvo US, Inc. - Inventors: Charles Forrest Campbell - Web page: https://patentgrep.com/patent/US12224717B2 ## CPC - H03F 1/0211: {with control of the supply voltage or current} - H03F 1/42: Modifications of amplifiers to extend the bandwidth - H03F 1/565: {using inductive elements} - H03F 3/195: in integrated circuits - H03F 3/605: {Distributed amplifiers} - H03F 2200/36: the amplifier comprising means for increasing the bandwidth - H03F 2200/451: the amplifier being a radio frequency amplifier - H03F: AMPLIFIERS ## Abstract Embedded blocking capacitor structures for wideband amplifier circuits are disclosed. A wideband amplifier circuit includes transistors that output radio frequency (RF) signals. An embedded blocking capacitor structure is operably connected between the terminals of the transistors and an RF output. The embedded blocking capacitor structure distributes a bias voltage to the terminals of the transistors and blocks the bias voltage from passing to the RF output. The embedded blocking capacitor structure also propagates an RF signal to an RF output. ## Claims ### Claim 1 An amplifier system, comprising: wideband amplifier circuitry comprising a plurality of transistors in an output stage of an amplifier circuit; and signal lines operably connected to terminals of the transistors, wherein the signal lines are used in an embedded blocking capacitor structure that operably connects the terminals of the transistors to a radio frequency (RF) output, the embedded blocking capacitor structure comprising at least one metal-insulator-metal capacitor. ### Claim 2 (depends on 1) The amplifier system of claim 1, further comprising a choke circuit operably connected between the embedded blocking capacitor structure and a power source. ### Claim 3 (depends on 2) The amplifier system of claim 2, wherein: the wideband amplifier circuitry and the embedded blocking capacitor structure are disposed in an integrated circuit; and the choke circuit is an off-chip choke circuit that is operably connected to the embedded blocking capacitor structure. ### Claim 4 (depends on 3) The amplifier system of claim 3, wherein the choke circuit is a conical inductor. ### Claim 5 (depends on 2) The amplifier system of claim 2, wherein: the wideband amplifier circuitry and the embedded blocking capacitor structure are disposed in an integrated circuit; and the choke circuit is an on-chip choke circuit that is operably connected to the embedded blocking capacitor structure. ### Claim 6 (depends on 5) The amplifier system of claim 5, wherein the choke circuit is a planar inductor. ### Claim 7 (depends on 2) The amplifier system of claim 2, wherein an airbridge is used to connect the choke circuit to the embedded blocking capacitor structure. ### Claim 8 (depends on 1) The amplifier system of claim 1, wherein: each transistor in the plurality of transistors is a field-effect transistor; and the signal lines are microstrip signal lines that operably connect drain terminals of the field-effect transistors to the RF output. ### Claim 9 (depends on 8) The amplifier system of claim 8, wherein a width of a first microstrip line in the microstrip signal lines differs from a width of a second microstrip line in the microstrip signal lines. ### Claim 10 (depends on 1) The amplifier system of claim 1, wherein: a first signal line is a first conductive plate of the embedded blocking capacitor structure and a second signal line is a second conductive plate of the embedded blocking capacitor structure; the first conductive plate is operably connected to the choke circuit; and the second conductive plate is operably connected to an output of the amplifier circuit. ### Claim 11 A wideband amplifier integrated circuit, comprising: amplifier circuitry comprising a transistor; and an embedded blocking capacitor structure operably connecting a terminal of the transistor to a radio frequency (RF) output, the embedded blocking capacitor structure comprising at least one blocking capacitor with a top conductive plate and a bottom conductive plate of the at least one blocking capacitor configured as signal lines. ### Claim 12 (depends on 11) The wideband amplifier integrated circuit of claim 11, further comprising a choke circuit operably connected between the top conductive plate of the embedded blocking capacitor structure and a power source. ### Claim 13 (depends on 12) The wideband amplifier integrated circuit of claim 12, wherein the choke circuit is an off-chip choke circuit that is operably connected to the embedded blocking capacitor structure. ### Claim 14 (depends on 13) The wideband amplifier integrated circuit of claim 13, wherein the off-chip choke circuit is a conical inductor. ### Claim 15 (depends on 11) The wideband amplifier integrated circuit of claim 11, wherein a width of the top conductive plate and a width of the bottom conductive plate are substantially equal along a length of the top conductive plate and a length of the bottom conductive plate. ### Claim 16 (depends on 11) The wideband amplifier integrated circuit of claim 11, wherein an airbridge connects the terminal of the transistor to the embedded blocking capacitor structure. ### Claim 17 (depends on 11) The wideband amplifier integrated circuit of claim 11, wherein: the top conductive plate is part of a first microstrip signal line that is configured to propagate a direct current voltage to the terminal of the transistor; the bottom conductive plate is part of a second microstrip signal line that is configured to propagate an RF signal to the RF output; and a dielectric material is disposed between the top conductive plate and opposing bottom conductive plate. ### Claim 18 (depends on 11) The wideband amplifier integrated circuit of claim 11, wherein a width of the top conductive plate and a width of the bottom conductive plate vary along a length of the top conductive plate and a length of the bottom conductive plate. ### Claim 19 (depends on 11) The wideband amplifier integrated circuit of claim 11, wherein the transistor is a field-effect transistor and the embedded blocking capacitor structure is operably connected to a drain terminal of the field-effect transistor. ### Claim 20 (depends on 11) The wideband amplifier integrated circuit of claim 11, wherein the at least one blocking capacitor comprises multiple blocking capacitors operably connected in parallel and distributed between a starting node of the embedded blocking capacitor structure and the RF output.