Leakage power measurement apparatus and method

A power measurement apparatus for measuring a ratio of power leaked from an adjacent channel to carrier power of a particular transmission channel of a communication device having a plurality of transmission channels wherein carrier power of the adjacent channel leaks to the particular transmission channel, said power measurement apparatus comprising:

• a frequency mixer which mixes an output of a local oscillator with a signal from the particular transmission channel of the communication device under test, said signal including the carrier power of the particular transmission channel and the carrier power of the adjacent channel leaked to the particular transmission channel ("leakage power") wherein frequencies of the carrier power of the particular transmission channel and the leakage power are different from one another;
• an A/D converter which converts an output signal of said frequency mixer to a digital signal using a predetermined sampling frequency;
• a Hilbert converter which converts said digital data into a complex signal;
• a low pass filter which removes unnecessary frequency components from said complex signal from said Hilbert converter;
• a frequency separation means for separating signals from said low pass filter into a signal corresponding to the leakage power from the adjacent channel and a signal corresponding to the carrier power of said particular transmission channel of said communication device under test;
• and
• a power processing unit which receives the signal corresponding to the carrier power of the particular transmission channel and the signal corresponding to the leakage power from the adjacent channel and calculates a ratio of said leakage power from said adjacent channel to said carrier power of said particular transmission channel of said communication device under test.