A disadv the pench is lower because the mesh itsefersthe carers The incident power density law distribution of the carriers on the sample can be easily evaluated on the basis of the TE10 funda sample wr.t the refector mesh. amers power correlation of the pim level of the 益中 vith that sources distance w.r.tthe PIM detector. MESH DESCRIPTION na (LdA)reflector is made nab as a ement of the mesh ires,the variety Fig.2-Mesh sample expanded view A disadvantage of the radiated test set-up is the limited sensitivity of the bench. Typically the sample must be illuminated at very high power densities not representative of the real carrier power densities as seen by the reflector antenna. In the conducted measurements case, based on a contactless waveguide set-up, this problem can be highly reduced because the attenuation factor due to the relative feed-sample distance does not apply. Additionally, the noise floor of the bench is lower because the mesh itself filters the carriers. The incident power density law distribution of the carriers on the sample can be easily evaluated on the basis of the TE10 fundamental propagating mode. Assuming a symmetrical scattering of the PIM (valid if the mesh thickness can be neglected), the received PIM power, scattered by the sample, is only a function of the carriers power density on the sample w.r.t. the reflector mesh. Therefore, the correlation of the PIM level of the sample with that on the feed placed in the reflector focal plane is proportional to the two areas ratio, properly weighted by a scalar factor which accounts for the impinging field intensity distribution over the two surfaces, the PIM roll-off Vs power and the set-up test type/geometry that correlate the PIM sources distance w.r.t the PIM detector. MESH DESCRIPTION The mesh of the Large Deployable Antenna (LDA) reflector is made of three wires of tungsten (twisted together) with the individual core diameter of 15-microns. Overcoat covering each micro-wire is made of gold (thickness 0.25- microns) lay over an intermediate layer of nickel (thickness 0.1/0.2-microns). The mesh installed on the reflector will have a nominal tension of 5/6 grams per cm along the piece and 7/8 grams per cm across the piece. A specially constructed mesh tension frame enabled measurements to be taken, as a function of tension, ranging from 1.0 to 60 grams per cm. The complex mesh structure suggested a number of potential mechanisms for PIM product generation: relative movement of the mesh wires, the variety and uncertainty of electrical contact points and their oxidation were potential PIM sources. So measurements were made under simulated environmental conditions including low-frequency vibrations, temperature variation and various tensions. Fig. 2 gives an expanded view of the mesh sample. Fig. 2-Mesh sample expanded view