Impedance transformation circuit for amplifier

Patent metadata

Field	Value
Publication number	US-2017194918-A1
Application number	US-201615389097-A
Country	US
Kind code	A1
Filing date	Dec 22, 2016
Priority date	Dec 30, 2015
Publication date	Jul 6, 2017
Grant date	—

Abstract

Aspects of this disclosure relate to an impedance transformation circuit for use in an amplifier, such as a low noise amplifier. The impedance transformation circuit includes a matching circuit including a first inductor. The impedance transformation circuit also includes a second inductor. The first and second inductors are magnetically coupled to each other to provide negative feedback to linearize the amplifier.

First claim

What is claimed is:

1 . A low noise amplifier comprising:
a matching circuit including a first inductor; an amplification circuit configured to receive a radio frequency signal by way of the first inductor and to amplify the radio frequency signal; and a second inductor, the first and second inductors magnetically coupled to each other to provide negative feedback to linearize the low noise amplifier.

2 . The low noise amplifier of claim 1 wherein the amplification circuit includes a common source amplifier and the second inductor is a source degeneration inductor.

3 . The low noise amplifier of claim 2 wherein the amplification circuit further includes a cascade transistor in series with the common source amplifier.

4 . The low noise amplifier of claim 1 wherein the amplification circuit includes a common emitter amplifier and the second inductor is an emitter degeneration inductor.

5 . The low noise amplifier of claim 4 wherein the amplification circuit further includes a cascade transistor in series with the common emitter amplifier.

6 . The low noise amplifier of claim 1 wherein the first inductor, the second inductor, and the amplification circuit of amplifier are embodied on a single die.

7 . The low noise amplifier of claim 1 wherein the matching circuit further includes a series inductor having a first end configured to receive the radio frequency signal and a second end electrically coupled to the first inductor.

8 . The low noise amplifier of claim 7 wherein the matching circuit further includes a shunt capacitor electrically coupled to the first end of the series inductor.

9 . The low noise amplifier of claim 7 wherein the matching circuit further includes a direct current blocking capacitor configured to provide the radio frequency signal to the series inductor.

10 . An impedance transformation circuit for use in an amplifier, the impedance transformation circuit comprising:
a matching circuit including a first inductor; and a second inductor, the first and second inductors magnetically coupled to each other to provide negative feedback to linearize the amplifier.

11 . The impedance transformation circuit of claim 10 wherein the second inductor is configured as a source degeneration inductor.

12 . The impedance transformation circuit of claim 10 wherein the second inductor is configured as an emitter degeneration inductor.

13 . The impedance transformation circuit of claim 10 wherein the first inductor is configured to provide a radio frequency signal to an amplification circuit of the amplifier.

14 . The impedance transformation circuit of claim 10 wherein the matching circuit further includes a series inductor having a first end configured to receive a radio frequency signal and a second end electrically coupled to the first inductor.

15 . A front end system comprising:
a low noise amplifier including a matching circuit including a first inductor, an amplification circuit configured to receive a radio frequency signal by way of the first inductor and to amplify the radio frequency signal, and a second inductor magnetically coupled with the first inductor to provide negative feedback to linearize the low noise amplifier; and a bypass path.

16 . The front end system of claim 15 further comprising a multi-throw switch having at least a first throw electrically connected to the low noise amplifier and a second throw electrically connected to the bypass path.

17 . The front end system of claim 16 further comprising a power amplifier, the multi-throw switch haying a third throw electrically coupled to the power amplifier.

18 . The front end system of claim 16 further comprising a second multi-throw switch having at least a first throw electrically connected to the low noise amplifier and a second throw electrically connected to the bypass path, the low noise amplifier being included in a first signal path between the multi-throw switch and the second multi-throw switch, and the bypass path being included in a second signal path between the multi-throw switch and the second multi-throw switch.

19 . The front end system of claim 16 wherein the multi-throw switch is configured to electrically connect an input of the low noise amplifier to an antenna port in a first state, and the multi-throw switch is configured to electrically connect the bypass path to the antenna port in a second state.

20 . The front end system of claim 15 wherein the amplification circuit includes a cascode transistor in series with either a common source amplifier or a common emitter amplifier.

Assignees

• Skyworks Solutions Inc

Inventors

• Wallis Leslie Paul

Classifications

• H03F2200/294

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

• H03F1/342

  in field-effect transistor amplifiers · CPC title

• H03F2200/18

  the bias of the gate of a FET being controlled by a control signal · CPC title

• H03F2200/387

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

• H03F1/223

  with MOSFET's · CPC title