Method and apparatus for regulating the power of a transmit amplifier
A method and apparatus for controlling the power of a transmit amplifier wherein a portion of the power transmitted from the antenna is received by a coupling element and is converted via a radio-frequency detector to a DC voltage value which is used for power control, such that there is no longer any need for complex use of a directional coupler between the transmit amplifier and the antenna.
1. A method for controlling the power of a transmit amplifier of a mobile radio terminal, the method comprising the steps of:
receiving a portion of the power transmitted from an antenna of the mobile radio terminal at the transmission end of said antenna by a coupling element of the mobile radio terminal; and
using the portion of the power transmitted to control the power of the transmit amplifier.
2. An apparatus for controlling the power of a transmit amplifier of a mobile radio terminal, comprising:
a part for receiving a portion of the power transmitted from an antenna of the mobile radio terminal; and
a part for controlling the power of the transmit amplifier as a function of the received portion of the power transmitted.
3. An apparatus for controlling the power of a transmit amplifier of a mobile radio terminal as claimed in claim 2 , wherein the antenna of the mobile radio terminal is a planar antenna having a first resonator mounted on a substrate, the part for receiving a portion of the power transmitted has a second resonator, and the first and second resonators are mounted on the same substrate.
4. An apparatus for controlling the power of a transmit amplifier of a mobile radio terminal as claimed in claim 2 , wherein the part for receiving a portion of the power transmitted is provided, during transmission operation of the mobile radio terminal, at least partially by a receiving antenna of the mobile radio terminal.