Patent ID: 7123889

Claim:
A radio transmitter testing method, for testing a radio transmitter comprising a feedback loop which feedback loop comprises a variable attenuator and a signal analyser, the method comprising: transmitting a signal on a predetermined radio channel, and conveying the transmitted signal to the feedback loop to generate a feed-back signal; attenuating the feed-back signal by the attenuator, defining power levels on the radio channel and on predetermined adjacent channels, and analyzing the power levels by the signal analyzer for generating a first result of analysis; changing attenuation level, attenuating the feed-back signal by the attenuator, defining power levels on the predetermined radio channel and on the predetermined adjacent channels, and analyzing the power levels by the signal analyzer for generating a second result of analysis; if the first and the second results of analysis are not the same, generating a test alarm; and if the first and second results of analysis are the same, delaying a transmitted signal to derive a reference signal; comparing the feed-back signal and the reference signal to generate an error vector, and if the error vector is not fulfilling predetermined criteria, generating a test alarm.