Krista Dahlberg

Mixer-Based Characterization of Millimeter-Wave and Terahertz Single-Anode and Antiparallel Schottky Diodes

This paper presents an alternative characterization method to the traditional characterization methods of the millimeter-wave and terahertz Schottky diodes. The diodes can be characterized based on the mixer operation (conversion loss and noise temperature) under comparable conditions. The tuning of the embedding impedances and the easy changing of the diode under test allow the comparison of different diodes in their actual operating environment. A fundamental mixer test jig and a subharmonic mixer test jig are designed for the characterization and comparison of different single-anode and antiparallel Schottky diodes, respectively, at 183 GHz. For the antiparallel diodes, the traditional capacitance extraction is not possible, thus alternative and additional characterization data is valuable. The diode manufacturers can exploit the mixer-based characterization to test the mixer operation of their diode and to reveal possible problems with the diode during the diode development process.

16-Term Error Model in Reciprocal Systems

By taking reciprocity of the error network into account, full and accurate calibration of a 16-term error model can be performed using only four two-port calibration standards or termination pairs. Moreover, there is no need for a nonsymmetrical calibration standard that is strictly required in a more conventional five-standard calibration. Commercially available standard substrates can thus be used. Detailed theory of the reciprocal 16-term error model and a new calibration method are presented. Reciprocity assumption is valid in on-wafer and other measurements when two-tier calibration is applied. However, the calibration scheme allows measurement of nonreciprocal devices too. The usefulness of the new method is confirmed by practical wideband on-wafer measurements.

A Method to Determine LRRM Calibration Standards in Measurement Configurations Affected by Leakage

This paper presents a novel method to define the calibration standards for the line-reflect-reflect-match method in a reciprocal 16-term error network. The procedure is based on four two-port calibration measurements: a thru line, a pair of matches, and two pure reactance pairs. The line standard and the resistance of the match standard need to be exactly known. The reactances of the match and lossless open and short standards are found using their raw S-parameter measurement data. The algorithm is limited to second-tier calibration of a reciprocal error network with a pre-calibrated network analyzer. Detailed theory of the method is presented and its functionality is demonstrated by practical on-wafer measurements and simulation.

Noncontacting Multiwaveguide-Band Backshort for Millimeter Wave Applications

In this letter a tunable, noncontacting and low loss waveguide backshort is presented. One backshort device is compatible with several standard waveguide sizes. The backshort is based on a quartz slab inserted in the E-plane of a rectangular waveguide. Simulation and measurement results for three standard millimeter waveguide bands are presented.