Investigating connection repeatability of waveguide devices at frequencies from 750 GHz to 1.1 THz

Abstract

This paper describes some investigations into the repeatability of connection of some waveguide devices in the WM-250 (WR-01) waveguide size over the recommended operational bandwidth 750 GHz to 1100 GHz. Three devices are investigated -a flush short-circuit, an offset short-circuit, and a near-matched load. These devices can be used as calibration standards for network analyzers, and so can be found in network analyzer calibration kits. The repeatability of the measured reflection coefficient is assessed using statistical techniques. The repeatability is expressed in terms of the experimental standard deviation in both the real and imaginary components of the complex-valued linear reflection coefficient. Finally, recommendations are given on propagating uncertainty when these devices are considered as calibration standards during a network analyzer calibration and measurement process.

Metrology State-of-the-Art and Challenges in Broadband Phase-Sensitive Terahertz Measurements

“…Poor repeatability introduces a significant component of random error in the measurement. Recent studies have shown that this can be a dominant source of error in the measurement [31][32][33].…”

Establishing Traceability to the International System of Units for Scattering Parameter Measurements From 750 GHz to 1.1 THz

“…It is for this reason that it is not generally feasible to provide a complete uncertainty budget for a particular DUT before it has been measured by the system. Some work on assessing DUT repeatability in this waveguide size has been undertaken recently [39][40][41] for some selected one-port devices. These were high-reflecting devices (a flush short-circuit and an offset short-circuit) and a lowreflecting device (a near-matched load).…”

“…These were high-reflecting devices (a flush short-circuit and an offset short-circuit) and a lowreflecting device (a near-matched load). It was found in [39] that experimental standard deviations, calculated from a series of 12 repeat measurements made under essentially the same condition of measurement, varied from approximately 0.01 to 0.1 (in terms of linear reflection coefficient). This is equivalent to a standard uncertainty of the order of 0.029 [24].…”

Evaluating the effect of using precision alignment dowels on connection repeatability of waveguide devices at frequencies from 750 GHz to 1.1 THz

“…Two recent papers [1,2] have presented investigations into the connection repeatability of some waveguide devices operating from 750 GHz to 1.1 THz (i.e. in the WM-250 waveguide size [3]).…”

“…This work used the same VNA test port and devices under test (DUTs) that were used for the previous investigations [1,2]. This enabled comparisons of connection repeatability performance to be made directly with these earlier investigations.…”