Coplanar load pull test fixture for wave measurements

[0030]Regular transistor test fixtures come in two basic forms: Micro-strip (MS) fixtures, FIG. 2 (see ref. 2) or Coplanar Waveguide (CPW) fixtures, FIG. 8 (see ref. 4). MS fixtures (see ref. 9) come in form of simple micro-strip, wherein there are one or more metallized strips 20 on the top surface and a continuous metallized ground plane 21 on the bottom side of the dielectric substrate 22. In the case of coplanar waveguide (CPW), FIG. 8, the ground plane 80 is on the same top surface as the signal conductor 81 (see ref. 4). Both those types of test fixtures can be enhanced by adding signal couplers 30, 82 inside the enclosure of the test fixture and close to the DUT (FIGS. 3 and 8); the directional signal sampling (FIG. 9) is created through capacitive (electric) or inductive (magnetic) coupling of a set of conductive wire bridges 86 or conductor sections 100 to the main signal transmission line 82, 101.

[0031]A typical micro-strip (MS) transistor test fixture (FIG. 2) comprises at l