Vector Network Analyzer Calibration Standards with Precision SMPS connectors for Electro-Optical Modulators

The paper demonstrates establishing calibration standard for vector network analyzers (VNA) evaluating electro-optical modulators (EO modulators). The latest EM modulators can operate over 60 GHz frequency. Connectors attached to EM modulators are small push on type connector, SMPS. For the specification of EM modules, return loss and insertion loss shall be evaluated by VNA, however, there is no calibration standards with SMPS connectors in VNA measurement. Therefore, users use conversion adapter/cable to attach to the modules, then the modules are measured at the connector end of 1.85 mm or 1.0 mm coaxial connectors. In the case, conversion adapter/cable makes large phase difference and transmission loss. Calibration standard shall be demonstrated In this study, we have developed and demonstrated SMPS calibration standard devices to adopt VNA calibration. In the calibration standard evaluation, calibration values are traced back to calibration standard s in 1.0 mm coaxial line. After calibration of SMPS standard devices, VNA calibration has been demonstrated under the overdetermined calibration scheme. As the results, VNA calibration uncertainties were less than 0.064, 0.112, 0.106, 0.062 and 0.061 at 15 GHz, 30 GHz, 50 GHz, 67 GHz and 80 GHz, respectively.

I. Introduction

5G telecommunication technologies lunched in the world, recently. 5G technologies makes innovation in the industry, business and also social society. High speed data communication requires high speed wireless telecommunication system at the last one mile. High speed optical core network (back bone) is also important in the 5G network. The trend of speed in the optical core network is 400 Gbps, and 1 Tbps is planned. In the EO modules, optical signal modulated by high frequency electric signal. The latest EO module has small push on coaxial connector, SPMS, as input port injecting high frequency signal, i.e over 60 GHz. We have established the calibration standards and calibrated them traceable to S-parameter standard in 1.0 mm coaxial line, then VNA calibration scheme is also demonstrated by using SPMS calibration standards.