Fortunately, with the development of a novel electronic line stretcher from Mini-Circuits, these once tedious tests can now be executed quickly and automatically.
To understand the significance of the new electronic line stretcher, it may help to review the traditional method of performing load pull tests on a VCO.
At this point, the mechanical line stretcher is manually tuned to cover the full 360-deg.
For measurements on a VCO with a carrier frequency of 250MHz and a 1000MHz line stretcher, testing must be performed in four steps.
Each electronic line stretcher is housed in a metal case with female SMA coaxial connectors on all ports.
Electronic line stretchers offer controlled phase shifts over wide frequency ranges to simplify once tedious VCO measurements.
Due to shortcomings of conventional electronic phase shifters and mechanical line stretchers, the engineers at Mini-Circuits sought a better method for performing VCO load-pull measurements.
The new electronic line stretchers are ideal for use in automated VCO load-pull test setups (Fig.