Conventional field strength sensors use different detection methods, each having advantages and disadvantages. Modern signals in, for instance, wireless communication systems and radars use very complex modulation. Other signals, such as the ones often measured in reverberation chambers with mode stirring, are fast-varying with high dynamic range. Conventional probes struggle to give reliable measurement data in these situations, while the more expensive solutions based on optical-electric conversion and heterodyne receiver, are so costly that often only one component of the field is measured. The impact of conventional field strength probes when measuring (complex) modulated signals is discussed. Furthermore, this paper describes the desig...