Wideband amplifier

Patent metadata

Field	Value
Publication number	US-12476594-B2
Application number	US-202217824802-A
Country	US
Kind code	B2
Filing date	May 25, 2022
Priority date	May 25, 2022
Publication date	Nov 18, 2025
Grant date	Nov 18, 2025

Abstract

A wideband amplifier includes an input matching network for matching a transconductor stage to an input impedance and includes an output matching network for matching the transconductor stage to an output impedance. Both the input and output matching networks each includes a parallel LC tank circuit arranged in parallel with a series LC tank circuit. The tank circuit arrangements configure the input and output matching networks to be resonant at a first frequency, a midrange frequency that is greater than the first frequency, and a second frequency that is greater than the midrange frequency to provide wideband matching.

First claim

What is claimed is:

1 . An amplifier, comprising:
a transconductor stage including a transconductor stage output node, the transconductor stage being configured to amplify an input signal; and an output matching network including:
a first inductor having a first terminal coupled to the transconductor stage output node;
an output transformer including a first coil electromagnetically coupled to a second coil, the first coil having a first terminal coupled to a reference voltage node and a second terminal coupled to a second terminal of the first inductor, the second coil being coupled to an amplifier output node; and
a first capacitor coupled between the second terminal of the first inductor and the reference voltage node.

2 . The amplifier of claim 1 , wherein the first capacitor is a variable capacitor, and wherein the reference voltage node is a power supply node for a power supply voltage.

3 . The amplifier of claim 1 , wherein the output matching network further includes a resistor coupled between the second terminal of the first inductor and the reference voltage node.

4 . The amplifier of claim 3 , wherein the resistor is a variable resistor.

5 . The amplifier of claim 1 , wherein the output matching network further includes:
a second capacitor coupled between the transconductor stage output node and the reference voltage node.

6 . The amplifier of claim 5 , wherein the output matching network further includes:
a resistor coupled between the transconductor stage output node and the reference voltage node.

7 . The amplifier of claim 6 , wherein the second capacitor is a variable capacitor and the resistor is a variable resistor.

8 . The amplifier of claim 1 , wherein an inductance of the first coil is greater than an inductance of the second coil.

9 . The amplifier of claim 1 , wherein the transconductor stage comprises:
a first transconductor transistor, wherein an input node of the transconductor stage is formed by a gate of the first transconductor transistor; and a first cascode transistor having a source coupled to a drain of the first transconductor transistor and having a drain coupled to the transconductor stage output node.

10 . The amplifier of claim 9 , wherein the transconductor stage further comprises:
a second transconductor transistor, wherein the input node of the transconductor stage is further formed by a gate of the second transconductor transistor, and a second cascode transistor having a source coupled to a drain of the second transconductor transistor and having a drain coupled to the transconductor stage output node.

11 . The amplifier of claim 9 , further comprising:
a degeneration inductor coupled between a source of the first transconductor transistor and ground.

12 . The amplifier of claim 10 , further comprising:
a bias generator configured to generate a first gate bias voltage for a gate of the first cascode transistor and configured to generate a second gate voltage for a gate of the second cascode transistor; and a controller configured to control the bias generator to adjust the first gate bias voltage and the second gate bias voltage to control a gain of the transconductor stage.

13 . The amplifier of claim 1 , wherein the output matching network further comprises a second capacitor coupled between the second coil and the amplifier output node.

14 . The amplifier of claim 1 , further comprising:
an input matching network coupled between an amplifier input node and an input node of the transconductor stage.

15 . The amplifier of claim 14 , wherein the input matching network includes a second inductor coupled between ground and the amplifier input node; a capacitor having a first terminal and a second terminal, wherein the second terminal of the capacitor is coupled to the input node of the transconductor stage; and a third inductor coupled between the amplifier input node and the first terminal of the capacitor.

16 . The amplifier of claim 1 , wherein the amplifier comprises a low-noise amplifier integrated within a receiver comprising:
a mixer coupled to the amplifier output node; an analog-to-digital converter; and a filter coupled between an output node of the mixer and an input node to the analog-to-digital converter.

17 . The amplifier of claim 1 , further comprising:
a plurality of electrostatic discharge diodes coupled to the amplifier output node.

18 . The amplifier of claim 1 , further comprising:
a plurality of electrostatic discharge diodes coupled to an amplifier input node of the amplifier.

19 . An amplification method, comprising:
transconducting a first input voltage signal through a transconductor stage having an output capacitance to form a first output current signal; and driving the first output current signal into a parallel combination of a series inductor-capacitor tank circuit and a first parallel inductor-capacitor tank circuit, wherein the series inductor-capacitor tank circuit includes the output capacitance and an inductor coupled between a first coil of an output transformer and an output node of the transconductor stage and the first parallel inductor-capacitor tank circuit includes a capacitor arranged in parallel with the first coil of the output transformer, to cause both the series inductor-capacitor tank circuit and the first parallel inductor-capacitor tank circuit to be resonant at a midrange frequency to match an impedance of an amplifier output node at the midrange frequency to an output resistance of the transconductor stage, wherein the midrange frequency is greater than a first frequency and less than a second frequency.

20 . The method of claim 19 , wherein driving the first output current signal into the parallel combination of the series inductor-capacitor tank circuit and the first parallel inductor-capacitor tank circuit further comprises:
causing the series inductor-capacitor tank circuit to function as a short circuit.

21 . The method of claim 19 , further comprising:
transconducting a second input voltage signal through the transconductor stage to form a second output current signal; and driving the second output current signal into the parallel combination of the series inductor-capacitor tank circuit and the first parallel inductor-capacitor tank circuit to cause a combination of the first coil and the output capacitance to function as a second parallel inductor-capacitor tank circuit that is resonant at the first frequency to match an impedance of the amplifier output node at the first frequency to a product of the output resistance of the transconductor stage and a quality factor of the series inductor-capacitor tank circuit.

22 . The method of claim 21 , wherein driving the second output current signal into the parallel combination of the series inductor-capacitor tank circuit and the first parallel inductor-capacitor tank circuit further comprises:
causing the second parallel inductor-capacitor tank circuit to function as an open circuit.

23 . The method of claim 21 , further comprising:
transconducting a third input voltage signal through the transconductor stage to form a third output current signal; and driving the third output current signal into the parallel combination of the series inductor-capacitor tank circuit and the first parallel inductor-capacitor tank circuit to cause a combination of the capacitor and the inductor to function as a third parallel inductor-capacit

Assignees

• Qualcomm Inc

Inventors

• Kord Ahmed
• Gatta Francesco
• Uzunkol Mehmet
• Hanafi Bassel

Classifications

• H03H7/38

  Impedance-matching networks · CPC title

• H03F2200/387

  A circuit being added at the output of an amplifier to adapt the output impedance of the amplifier · CPC title

• H03F2200/318

  A matching circuit being used as coupling element between two amplifying stages · CPC title

• H03F2200/294

  the amplifier being a low noise amplifier [LNA] · CPC title

• H03F2200/225

  the input circuit of an amplifying stage comprising an LC-network · CPC title