Note: Vector reflectometry in a beam waveguide

Abstract

We present a one-port calibration technique for characterization of beam waveguide components with a vector network analyzer. This technique involves using a set of known delays to separate the responses of the instrument and the device under test. We demonstrate this technique by measuring the reflected performance of a millimeter-wave variable-delay polarization modulator.

Aerogel scattering filters for cosmic microwave background observations

“…VNA reflectance measurements were taken multiple (∼ 5) times with sample positions translated by approximately λ/5 each time, following the method outlined in Ref. 26.…”

The cosmology large angular scale surveyor (CLASS) telescope architecture

“…The VPM polarization transfer function for prototype VPMs has been measured and shown to be well-described using a transmission line model [14], [16].…”

A translational polarization rotator

“…This linear stage was used to vary the position of the TPR ("B" in Figure 4) relative to the rest of the optics. By taking measurements of the response at different positions of the TPR, it was possible to use the varied phase to separate the TPR response from that of the rest of the optics using a procedure similar to that outlined by Eimer et al [19]. Thus each S 21 scattering parameter measurement described below is a composite of four measurements taken at 400 µm intervals for the TPR position.…”