Test Chamber Characteristics - Important Factor Determining Required RF Power of Amplifier in Radiated Immunity Tests

Field uniformity on a hypothetical vertical plane (uniform field area) is the only criterion regarding the field distribution in a test site which must be fulfilled according to applicable immunity standards. In the paper it has been shown that the required field uniformity can be obtained even in case of the sites which characteristics restrict the practical usefulness of them in a very serious way. This is due to very high power demands for the RF amplifiers providing antenna drive to the necessary field strength level. Computing the required value of the RF amplifier output power disregarding the influence of test chamber characteristics on it can cause serious underestimate of this power with all technical and (first of all) economical consequences of the purchase of improperly sized amplifier.