Method and arrangement for detecting load mismatch, and a radio device utilizing the same

An arrangement for detecting impedance mismatch between an output of a radio frequency amplifier and an input of a load coupled to the output of the radio frequency amplifier, of which the radio frequency amplifier comprises an amplifying component, the arrangement comprising:

• first monitoring means adapted to monitor a measurable electric effect at other a side of the amplifying component other than the load and to produce a first measurement signal,
• second monitoring means adapted to monitor a measurable electric effect between the amplifying component and the load and to produce a second measurement signal, and
• decision-making means adapted to receive said first and second measurement signals and to decide, whether said first and second measurement signals together indicate impedance mismatch, wherein:
• the radio frequency amplifier comprises amplifying components that constitute a chain of amplifying stages, of which one is an output stage, and which chain of amplifying stages is coupled between an input and an output of the radio frequency amplifier,
• said first monitoring means is adapted to monitor a measurable electric effect between said input of the radio frequency amplifier and said output stage, and
• said second monitoring means is adapted to monitor a measurable electric effect between said output stage and said output of the radio frequency amplifier.

A mobile telecommunication device, comprising:

• a transmitter block,
• within the transmitter block a radio frequency amplifier having an amplifying component and an output port, and
• an antenna coupled to the output port of the radio frequency amplifier;
• wherein for detecting impedance mismatch between the antenna and the output port of the radio frequency amplifier the mobile telecommunication device comprises:
• first monitoring means adapted to monitor a measurable electric effect at a side of the amplifying component other than the antenna and to produce a first measurement signal,
• second monitoring means adapted to monitor a measurable electric effect between the amplifying component and the antenna and to produce a second measurement signal, and
• decision-making means adapted to receive said first and second measurement signals, to compare said first measurement signal to said second measurement signal and to decide on the basis of such comparing, whether said first and second measurement signals together indicate impedance mismatch.

A method for detecting impedance mismatch between an output of a radio frequency amplifier and an input of a load coupled to the output of the radio frequency amplifier, comprising:

• monitoring a measurable electric effect at a side of an amplifying component within the radio frequency amplifier other than the load, and producing a first measurement signal,
• monitoring a measurable electric effect between said amplifying component within the radio frequency amplifier and the load, and producing a second measurement signal,
• comparing said first measurement signal to said second measurement signal and
• deciding on the basis of such comparing, whether said first and second measurement signals together indicate impedance mismatch.