System and method for quickly power amplifier control

1. A system for power amplifier control, the system comprising:

an automatic gain controller;

a variable gain amplifier having an input coupled to an output of the automatic gain controller;

a fixed gain amplifier having an input coupled to an output of the variable gain amplifier and having an output coupled to an input of the automatic gain controller;

a radio frequency antenna having an input coupled to the output of the fixed gain amplifier;

a storage module; and

a processor, configured to:

before the fixed gain amplifier is disabled and after the automatic gain controller adjusts gain for a last time, read a reference transmit power value from the automatic gain controller, read a gain level from the fixed gain amplifier, and save the reference transmit power value and the gain level in the storage module; and

before the fixed gain amplifier is enabled and after the automatic gain controller adjusts gain for the last time, write the reference transmit power value saved in the storage module into the automatic gain controller and write the gain level saved in the storage module into the fixed gain amplifier.

2. The system according to claim 1 , wherein the processor is further configured to control the automatic gain controller to temporarily stop working during a period of time from the time when the fixed gain amplifier is disabled to the time when the fixed gain amplifier is enabled.

3. A method for controlling a power amplifier, the method comprising:

before a fixed gain amplifier is disabled and after an automatic gain controller adjusts gain for a last time, reading a reference transmit power value from the automatic gain controller and reading a gain level from the fixed gain amplifier and saving the reference transmit power value and the gain level in a storage module; and

before the fixed gain amplifier is enabled and after the automatic gain controller adjusts gain for the last time, writing the reference transmit power value saved in the storage module into the automatic gain controller and writing the gain level saved in the storage module into the fixed gain amplifier.

4. The method according to claim 3 , further comprising controlling the automatic gain controller to temporarily stop working during a period of time from the time when the fixed gain amplifier is disabled to the time when the fixed gain amplifier is enabled.

5. The method according to claim 3 , wherein before the reading a reference transmit power value from the automatic gain controller and reading a gain level from the fixed gain amplifier, the method further comprises:

determining whether the fixed gain amplifier is disabled according to a state flag bit in the fixed gain amplifier; and

if the fixed gain amplifier is not disabled, reading the reference transmit power value from the automatic gain controller and reading the gain level from the fixed gain amplifier.

6. The method according to claim 3 , wherein before writing the reference transmit power value saved in the storage module into the automatic gain controller and writing the gain level saved in the storage module into the fixed gain amplifier, the method further comprises:

determining whether the fixed gain amplifier is enabled according to a state flag bit in the fixed gain amplifier; and

if the fixed gain amplifier is not enabled, writing the reference transmit power value saved in the storage module into the automatic gain controller and writing the gain level saved in the storage module into the fixed gain amplifier.

7. A method for controlling a power amplifier, the method comprising:

reading a reference transmit power value from an automatic gain controller;

reading a gain level from a fixed gain amplifier;

saving the reference transmit power value and the gain level in a storage module;

disabling the fixed gain amplifier after saving the reference transmit power value and the gain level in the storage module;

adjusting gain by the automatic gain controller after saving the reference transmit power value and the gain level in the storage module;

after the automatic gain controller adjusts gain for a last time, writing the reference transmit power value saved in the storage module into the automatic gain controller;

after the automatic gain controller adjusts gain for the last time, writing the gain level saved in the storage module into the fixed gain amplifier; and

after writing the reference transmit power value and the gain level into the fixed gain amplifier, enabling the fixed gain amplifier.

8. The method according to claim 7 , further comprising controlling the automatic gain controller to temporarily stop working during a period of time from the time when the fixed gain amplifier is disabled to the time when the fixed gain amplifier is enabled.

9. The method according to claim 7 , wherein before reading the reference transmit power value from the automatic gain controller and reading the gain level from the fixed gain amplifier, the method further comprises:

determining whether or not the fixed gain amplifier is disabled according to a state flag bit in the fixed gain amplifier;

if the fixed gain amplifier is not disabled, reading the reference transmit power value from the automatic gain controller and reading the gain level from the fixed gain amplifier; and

if the fixed gain amplifier is disabled, writing the reference transmit power value saved in the storage module into the automatic gain controller and writing the gain level saved in the storage module into the fixed gain amplifier.