Load Pull Measurements

Since 1988, Focus Microwave Group has been a key supplier of advanced Load Pull and Noise Tuner Systems. Copper Mountain Technologies instruments work with the company’s load pull systems. An impedance tuner is an apparatus, which generates a controllable reflection factor (Impedance) over a certain frequency range. Focus uses two basic technologies:

a) For frequencies from 100MHz to 110GHz (and above) we use the slide screw technique (models Multi Harmonic MPT, wideband (fundamental) CCMT), in which a reflective probe (slug) is inserted into the slot of a low loss slotted transmission line (slabline or waveguide).

b) For frequencies from below 10MHz to 170MHz we use a lumped element technology (models LFT), whereby variable capacitors are connected with optimized lengths of coaxial cable.

For load pull measurements, the VNA plays a critical role. The VNA is a driving force for load pull measurements. Small form factor also reduces the footprint of what is typically a very large test setup. A benefit of using CMT USB VNAs is that both software programs are running simultaneously on the computer reducing latency. Time Domain comes standard in the CMT VNA software. The Direct Receiver Access (DRA) models of the Cobalt VNAs allow for load pull measurements at higher power. And for some applications, Copper Mountain Technologies’ 4-port Cobalt VNAs have two generators inside allowing for use of two sources at the same time.

Copper Mountain Technologies’ VNAs compatible with Focus Microwaves: