Design of a New Miniaturized Microwave Vector Network Analyzer

Abstract

Vector Network Analyzer (VNA) is a microwave measurement device that is used to characterize different Radio Frequency (RF) components. It measures the scattering parameters of RF devices in order to determine their electrical behavior for an accurate characterization and analysis of RF circuits.

The VNA consists of many RF components that are connected together in order to enable suitable S-parameters measurement of a device under test (DUT). In addition, a software controls the interaction between the different components and the DUT in order to determine its parameters and characteristics.

The focus of this thesis is on the novel design of one component in the RF chain of the VNA. This component, which is the power divider, is responsible for dividing the input RF power into two output branches. This thesis presents a new continuous phase tunable Wilkinson power divider. The tuning of the power divider enables the extraction of a variable phase difference between the two output ports of the power divider. The presented power divider is compact, reconfigurable and relies on two varactor diodes to achieve output phase tuning between 0o and 55o.

The proposed design maintains very good impedance matching and isolation across the entire operating bandwidth from 2 GHz to 3.8 GHz and across all the various phase states. Such tuning potential of the power divider enables its wide integration into advanced VNA RF chains, feeding networks of phased arrays, and new communication platforms.