Switchable supply and tunable load impedance power amplifier

Abstract

A transceiver configured to transmit data in a plurality of operating modes including a Wi-Fi mode and two or more different Bluetooth power modes, the transceiver comprising: a first power amplifier configured to amplify Bluetooth signals; a second power amplifier configured to amplify Wi-Fi signals; an antenna coupled to the second power amplifier; and a tunable load circuit, coupled between the first amplifier and the second amplifier, configured to provide a different load impedance for each of the plurality of operating modes, the tunable load circuit consisting of: two impedance paths coupled in parallel between output terminals of the first and second amplifiers; and a number of shunt paths coupled between the tunable load circuit and ground potential.

Description

TECHNICAL FIELD[0001]The present embodiments relate generally to wireless communications systems, and specifically to tunable load impedances for shared-antenna wireless communications systems.BACKGROUND OF RELATED ART[0002]Modern wireless communications devices typically include multiple wireless radios (e.g., Bluetooth®, Wi-Fi, etc.). To achieve a smaller footprint, multiple wireless radios may share the same antenna. For example, a wireless device may include a Bluetooth radio and a Wi-Fi radio coupled to a single antenna. The Bluetooth radio may include a Bluetooth power amplifier to drive (e.g., amplify) outgoing data signals in accordance with one or more Bluetooth standards. The Wi-Fi radio may include a Wi-Fi power amplifier to drive outgoing data signals in accordance with one or more IEEE 802.11 standards. The Bluetooth and Wi-Fi radios typically operate on the 2.4 GHz frequency band, and may share an antenna to transmit signals to other wireless devices and / or to receive ...

AI Technical Summary

Benefits of technology

[0007]Systems and methods are disclosed that may maximize power efficiency of both a Bluetooth power amplifier and a Wi-Fi power amplifier which share an antenna coupled to radio frequency input / output (RFIO) circuit. In accordance with example embodiments, an analog front-end (AFE) circuit for use in a transceiver of a wireless device is disclosed that includes at least a Bluetooth power amplifier, a Wi-Fi power amplifier, and a tunable load circuit. The tunable load circuit may be dynamically configured and / or adjusted to provide different load impedances for the Wi-Fi power amplifier and the Bluetooth power amplifier based on an operating mode of the AFE circuit. In addition, the AFE circuit may include a switchable power supply that may be dynamically configured to provide a number of different supply voltages to the Bluetooth power amplifier based on a Bluetooth power mode (e.g., Bluetooth high power mode, Bluetooth low power mode, and Bluetooth ultra-low power mode). The tunable load circuit may also prevent damage to the Bluetooth power amplifier when the AFE circuit is transmitting Wi-Fi signals from the antenna.

Problems solved by technology

For wireless devices including a Wi-Fi power amplifier and a Bluetooth power amplifier that share the same output load, it may be difficult to configure the output load in a manner that optimizes power transmission efficiency for both the Wi-Fi power amplifier and the Bluetooth power amplifier.

Further, for wireless devices in which an antenna is shared between the Wi-Fi power amplifier and the Bluetooth power amplifier, it may be difficult to ensure reliability of the Bluetooth power amplifier when the Wi-Fi power amplifier is transmitting (e.g., because the Wi-Fi power amplifier typically drives Wi-Fi signals at higher power levels than the power levels to which the Bluetooth power amplifier drives Bluetooth signals).

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