|
Nicolson–Ross–Weir Method
Nicolson–Ross–Weir method is a measurement technique for determination of complex permittivities and permeabilities of material samples for microwave frequencies. The method is based on insertion of a material sample with a known thickness inside a waveguide, such as a coaxial cable or a rectangular waveguide, after which the dispersion data is extracted from the resulting scattering parameters. The method is named after A. M. Nicolson and G. F. Ross, and W. B. Weir, who developed the approach in 1970 and 1974, respectively. The technique is one of the most common procedures for material characterization in microwave engineering. Method The method uses scattering parameters of a material sample embedded in a waveguide, namely S_ and S_, to calculate permittivity and permeability data. S_ and S_ correspond to the cumulative reflection and transmission coefficient of the sample that are referenced to the each sample end, respectively: these parameters account for the multiple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Group Delay And Phase Delay
In signal processing, group delay and phase delay are functions that describe in different ways the delay times experienced by a signal’s various sinusoidal frequency components as they pass through a linear time-invariant (LTI) system (such as a microphone, coaxial cable, amplifier, loudspeaker, communications system, ethernet cable, digital filter, or analog filter). Unfortunately, these delays are sometimes frequency dependent, which means that different sinusoid frequency components experience different time delays. As a result, the signal's waveform experiences distortion as it passes through the system. This distortion can cause problems such as poor fidelity in analog video and analog audio, or a high bit-error rate in a digital bit stream. Background Frequency components of a signal Fourier analysis reveals how signals in time can alternatively be expressed as the sum of sinusoidal frequency components, each based on the trigonometric function \sin(x) with a fixed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IEEE Transactions On Microwave Theory And Techniques
''IEEE Transactions on Microwave Theory and Techniques'' (T-MTT) is a monthly peer-reviewed scientific journal with a focus on that part of engineering and theory associated with microwave/millimeter-wave technology and components, electronic devices, guided wave structures and theory, electromagnetic theory, and Radio Frequency Hybrid and Monolithic Integrated Circuits, including mixed-signal circuits, from a few MHz to THz. T-MTT is published by the IEEE Microwave Theory and Techniques Society. T-MTT was established in 1953 as the ''Transactions of the IRE Professional Group on Microwave Theory and Techniques.'' From 1955 T-MTT was published as the ''IRE Transactions on Microwave Theory and Techniques'' and was finally the current denomination since 1963. The editors-in-chief is Almudena Suarez (University of Cantabria). According to the ''Journal Citation Reports'', the journal has a 2023 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vector Network Analyzer
A network analyzer is an instrument that measures the network parameters of electrical networks. Today, network analyzers commonly measure s–parameters because reflection and transmission of electrical networks are easy to measure at high frequencies, but there are other network parameter sets such as y-parameters, z-parameters, and h-parameters. Network analyzers are often used to characterize two-port networks such as amplifiers and filters, but they can be used on networks with an arbitrary number of ports. Overview Network analyzers are used mostly at high frequencies; operating frequencies can range from 1 Hz to 1.5 THz. Special types of network analyzers can also cover lower frequency ranges down to 1 Hz. These network analyzers can be used, for example, for the stability analysis of open loops or for the measurement of audio and ultrasonic components. The two basic types of network analyzers are * scalar network analyzer (SNA)—measures amplitude p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
