Electronic device with data-rate-dependent power amplifier bias

Abstract

Wireless circuitry in an electronic device may contain output power amplifier circuitry for amplifying transmitted radio-frequency signals. The power amplifier circuitry may be powered using a bias voltage. The magnitude of the bias voltage can be selectively reduced to conserve power. Control circuitry can maintain a table of bias voltage settings to use under various conditions. These conditions may include required output powers as determined by link quality, transmission mode status, and required data rates. When link quality is low or when high data rates are required, the bias voltage can be maintained at a relatively high level to ensure that the power amplifier operates linearly and does not exhibit excessive noise. When link quality is high or when data rates are low as with voice calls, the bias voltage can be reduced to conserve power.

Description

technical field

[0001] The present invention relates generally to wireless communication circuits, and more particularly to wireless communication circuits for power amplifier bias adjustment. Background technique

[0002] Handheld electronic devices and other portable electronic devices are becoming increasingly popular. Examples of handheld devices include handheld computers, cellular telephones, and media players. Popular portable electronic devices that are slightly larger than traditional handheld electronic devices include laptop computers and tablet computers.

[0003] Due in part to their mobile nature, portable electronic devices are often provided with wireless communication capabilities. For example, handheld electronic devices may use long-range wireless communications to communicate with wireless base stations. Cellular phones and other cellular-enabled devices can communicate using the 850 MHz, 900 MHz, 1800 MHz, and 1900 MHz cellular phone bands. It can al...

Images