There are only a few wireless measurement platforms on the market that can be used right out of the box. They all rely on a digitized signal to avoid a compander circuit (rendering most RF systems useless for measurement purposes). Even with a digital RF system useful for wireless measurement purposes, each system I am aware of exhibits various frequency and phase related artifacts. Beyerdynamic recently began to offer a measurement capsule compatible with their existing TG1000 digital wireless rig. Below is a review of the system by Fedele de Marco including measurement results.