Combined differential-mode and common-mode (mixedmode) scattering parameters (s-parameters) are well adapted to accurate measurements of linear networks at RF and microwave frequencies. The relationships between standard s-parameters with two-port vector network analyzer (VNA) and mixed-mode s-parameters with four-port VNA are derived in this paper. An example differential structure was measure...

In this era of the Internet of Things, we designed a rectenna working at 5.8 GHz in order to solve the finite things about battery-powered wireless sensor. First, an E-shape embedded microstrip feed antenna by HFSS software has been designed, then a technique called “offset correction” to balance the deviation between theory and simulation was proposed. It effectively spanned the gap between si...

This paper presents modeling of the complex permeability spectra, fabrication and a wide frequency range characterization of a toroidal LTCC ferrite sample. A commercial ferrite tape ESL 40012 is used, and standard LTCC (Low Temperature Co-fired Ceramic) processing has been applied to the sample fabrication. The characterization was performed using a short coaxial sample holder and a vector net...

For the design of an antenna that will be directly attached to a car tire, the proximity effects due to the tire have to be considered. Measurements are performed on a dipole antenna that is mounted at the inside of the tire tread to determine the change in input impedance and resonant frequency caused by the dielectric rubber material and the metal reinforcement of the tire. A differential mea...

This paper presents a fast and easy to use method to determine permittivity and loss tangent in the frequency range of 75 to 325 GHz. To obtain the permittivity and the loss tangent of the test material, the reflection and transmission S-parameters of a waveguide section filled with the test material are measured using a vector network analyzer and then compared with the simulated plots from a ...

A broadband MEMS steerable antenna is fabricated on a silicon substrate using bulk micromachining techniques. The MEMS platform utilizes torsion hinges and is capable of rotation around two axes for full beam steering capabilities. The antenna was designed using the Ansoft High Frequency Structure Simulator (HFSS) package and operates between 10-16 GHz with a coplanar feedline routed across the...

We describe a spectrometer consisting of a vector network analyzer, a gas absorption cell, and a quasi-optical bench that acquires terahertz spectra of gaseous substances and mixtures. We tested volatile organic compounds that are medical biomarkers or chemicals which can be found on the US Environment Protection Agency list of harmful substances. Absorption spectra at gas pressures between 10 ...

This paper describes a procedure for frequency dependent modeling of power transformers from measured terminal characteristics. The admittance matrix is measured in the frequency domain using a network analyzer and a dedicated measurement setup. Subsequent approximation of the admittance matrix with rational functions using Vector Fitting gives an EMTP-type compatible model suitable for transie...

Mechanical details as well as electrical models of FDR (frequency domain reflectometry) sensors for the measurement of the complex dielectric permittivity of porous materials are presented. The sensors are formed from two stainless steel parallel waveguides of various lengths. Using the data from VNA (vector network analyzer) with the connected FDR sensor and selected models of the applied sens...

Substrate integrated waveguide (SIW) is a new form of transmission line. It facilitates the realization of nonplanar (waveguide based) circuits into planar form for easy integration with other planar (microstrip) circuits and systems. This paper describes the design of an SIW to microstrip transition. The transition is broadband covering the frequency range of 8 – 12GHz. The measured in-band in...