Measurement of magnitude and phase of harmonics generated in nonlinear microwave two-ports

Systematic Calibration of Two-Port Network Analyzer for Measurement and Engineering of Waveforms at Radio Frequency

“…The developed calibration strategy discards the use of the golden standard and, thus, significantly improves the existing calibration techniques reported earlier [7,9,13]. It has been systematically proven that the developed calibration procedure and measurements provide accurate results.…”

“…However, most of the time the determination of absolute phase values of the error terms at harmonic frequencies rely on a certain type of nonlinear golden standard in achieving the desired accuracy in phase calibration and measurements. Some of the systems rely on step recovery diode (SRD) [1] while some others rely on active device based standard phase reference generators [11][12][13][14]. There has been report of alternative calibration technique [15] that requires several procedural steps in order to perform the necessary calibration, but this is a tedious process and is not straightforward.…”

Practical applications of nonlinear measurements

“…In this way, the relative phase of each frequency component can be reconstructed as it is measured (see Figure 7(c)). This system retains the high dynamic range of a VNA, as do the earlier VNAbased systems described in [13,14], which used diode-based comb generators as phase references. As with the instruments described above, the excitation must be periodic, so that the signals can be sampled and reconstructed.…”

“…In many respects, the VSA is like a real-time sampling oscilloscope, but higher dynamic range and frequency resolution are obtained by limiting the acquisition bandwidth. As mentioned above, several types of nonlinear measurement systems have been developed to provide impedance information in addition to absolute magnitude and phase, including [6][7][8][9][10][11][12][13][14][15][16][17][18][19]. These instruments use impedance standards and directional couplers to separate the incident and reflected waves and transform the measured impedances to the reference plane of the OUT.…”

Polyharmonic Distortion Modelling Applied to Acoustic Characterisation of Peforates

“…Essentially linear system identification theory was however used assuming that superposition applies and that the functions studied are analytical. Polyharmonic distortion modelling [15][16][17][18][19][20] , used for studying the nonlinear properties of microwave systems, does not assume that the function relating waves incident and reflected or transmitted is analytic nor does it assume application of normal superposition. For many years socalled Virtual Network Analysers have been used to characterise linear properties of microwave systems.…”