Circuits and devices related to fast turn-on of radio-frequency amplifiers

Patent metadata

Field	Value
Publication number	US-2016013760-A1
Application number	US-201514797326-A
Country	US
Kind code	A1
Filing date	Jul 13, 2015
Priority date	Jul 14, 2014
Publication date	Jan 14, 2016
Grant date	—

Abstract

Circuits, methods and devices are disclosed, related to fast turn-on of radio-frequency (RF) amplifiers. In some embodiments, an RF amplifier circuit includes an amplification path implemented to amplify an RF signal, where the amplification path includes a switch and an amplifier. In some embodiments, each of the switch and the amplifier are configured to be ON or OFF to thereby enable or disable the amplification path, respectively. In some embodiments, the RF amplifier circuit includes a compensation circuit coupled to the amplifier, where the compensation circuit is configured to compensate for a slow transition of the amplifier between its ON and OFF states resulting from a signal applied to the switch.

First claim

What is claimed is:

1 . A radio-frequency (RF) amplifier circuit comprising:
an amplification path implemented to amplify an RF signal, the amplification path including a switch and an amplifier, each of the switch and the amplifier configured to be ON or OFF to thereby enable or disable the amplification path, respectively; and a compensation circuit coupled to the amplifier, the compensation circuit configured to compensate for a slow transition of the amplifier between its ON and OFF states resulting from a signal applied to the switch.

2 . The circuit of claim 1 wherein the amplification path further includes a DC blocking capacitance implemented between the switch and the amplifier.

3 . The circuit of claim 2 wherein each of the switch and the amplifier includes a field-effect transistor (FET) having a gate, a source, and a drain.

4 . The circuit of claim 3 wherein the FET switch is configured to be in the ON state to allow passage of the RF signal between the source and the drain upon an application of a positive edge switch signal to the gate.

5 . The circuit of claim 4 wherein the FET amplifier is configured to receive the RF signal from the FET switch and the DC blocking capacitance at its gate and output the amplified RF signal through its drain or source.

6 . The circuit of claim 5 wherein the amplified RF signal is output through the drain of the FET amplifier.

7 . The circuit of claim 5 wherein the FET amplifier is configured to be turned ON to allow amplification of the RF signal upon an application of a positive edge switch signal to the gate.

8 . The circuit of claim 7 wherein the signal applied to the switch includes a negative edge signal applied to the source and the drain of the FET switch to improve insertion loss performance of the FET switch, the negative edge signal coupling with the FET amplifier through the DC blocking capacitance to result in the slow transition of the FET amplifier from the OFF state to the ON state.

9 . The circuit of claim 8 wherein the compensation circuit includes a DC blocking capacitance coupled to the gate of the FET amplifier.

10 . The circuit of claim 9 wherein the DC blocking capacitance of the compensation circuit is configured to provide a capacitive coupling of a positive edge compensation signal to the gate of the FET amplifier to provide compensation for at least a portion of the capacitive coupled effect of the negative edge signal applied to the source and the drain of the FET switch.

11 . The circuit of claim 10 wherein the compensation provided by the capacitive coupling of a positive edge compensation signal results in a faster transition of the FET amplifier from the OFF state to the ON state.

12 . The circuit of claim 10 wherein the capacitive coupling of the positive edge compensation signal to the gate of the FET amplifier is configured to substantially cancel the capacitive coupled effect of the negative edge signal applied to the source and the drain of the FET switch.

13 . The circuit of claim 1 wherein the amplifier includes a low-noise amplifier (LNA).

14 . The circuit of claim 13 wherein the LNA is configured to amplify received WLAN signals.

15 . A radio-frequency (RF) module comprising:
a packaging substrate configured to receive a plurality of components; and an RF amplifier circuit implemented on the packaging substrate, the RF amplifier circuit including an amplification path implemented to amplify an RF signal, the amplification path including a switch and an amplifier, each of the switch and the amplifier configured to be ON or OFF to thereby enable or disable the amplification path, respectively, the RF amplifier circuit further including a compensation circuit coupled to the amplifier, the compensation circuit configured to compensate for a slow transition of the amplifier between its ON and OFF states resulting from a signal applied to the switch.

16 . The RF module of claim 15 wherein the RF module is a WLAN module.

17 . A wireless device comprising:
an antenna configured to facilitate transmission and receive operations; and an RF amplifier circuit in communication with the antenna, the RF amplifier circuit including an amplification path implemented to amplify an RF signal, the amplification path including a switch and an amplifier, each of the switch and the amplifier configured to be ON or OFF to thereby enable or disable the amplification path, respectively, the RF amplifier circuit further including a compensation circuit coupled to the amplifier, the compensation circuit configured to compensate for a slow transition of the amplifier between its ON and OFF states resulting from a signal applied to the switch.

18 . The wireless device of claim 17 wherein the amplifier is a low-noise amplifier (LNA) and the amplification path is configured to amplify the RF signal received through the antenna.

19 . The wireless device of claim 18 wherein the RF amplifier circuit further includes a power amplifier (PA) path configured to amplify an RF signal to be transmitted.

20 . The wireless device of claim 19 wherein each of the amplification path and the PA path is coupled to the antenna.

Assignees

• Skyworks Solutions Inc

Inventors

• Lam Lui
• Govind Vinu

Classifications

• H03F2203/7215

  the gated amplifier being switched on or off by a switch at the input of the amplifier · CPC title

• H03F1/0277

  Selecting one or more amplifiers from a plurality of amplifiers · CPC title

• H03F2200/294

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

• H03F2200/231

  the input of an amplifier can be switched on or off by a switch to amplify or not an input signal · CPC title

• H03F2200/18

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