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Transistor Modeling and Simulation
Published in Abdullah Eroglu, Introduction to RF Power Amplifier Design and Simulation, 2018
Prior to characterizing a component with a given network analyzer, it is first necessary to calibrate the instrument for a given test setup. This is done in order to remove the effects of test fixture in the measurement. Most of the modern network analyzers have integrated mathematical algorithms that can be utilized to calibrate out these effects seen by each port using standard network analyzer error models and thus allowing the user to more easily obtain accurate measurements. Better accuracy in measurement of the device characteristics can be obtained using full two-port calibration as discussed with the SOLT method. In SOLT calibration, the analyzer is subjected to a series of known configuration setups, as shown in Figure 3.32. During these measurements, the network analyzer obtains the S parameters of the fixture used. Once these are known, the network analyzer can easily remove the effects of fixturing through the utilization of an error matrix generated during calibration.
Wall Attenuation and Dispersion
Published in Moeness G. Amin, Through-the-Wall Radar Imaging, 2017
Ali Hussein Muqaibel, M.A. Alsunaidi, Nuruddeen Mohammed Iya, Ahmad Safaai-Jazi
In the frequency-domain technique, through-the-wall propagation measurements are performed at different frequencies using a sweep harmonic generator. The principal advantage of the frequency-domain technique over the time-domain method is the larger dynamic range. Each measured data point is represented by a complex number expressed by its magnitude and phase terms. Figure 1.6 illustrates the frequency-domain measurement setup. A network analyzer is used for performing sweep frequency measurements. As shown in this figure, port 1 of the S-parameter test set is connected to the transmitter, while port 2 is connected to the receiver. The network analyzer sweeps the frequency within the measurement band of interest. For wideband characterization, where a wide frequency range needs to be swept, one has to make a trade-off between the frequency resolution and the required number of measurements that is directly proportional to the time it takes to perform the experiment as well as data storage requirements.
Experimental investigation on bend-region crack detection using TE11 mode microwaves
Published in Nondestructive Testing and Evaluation, 2022
Guanren Chen, Takuya Katagiri, Noritaka Yusa, Hidetoshi Hashizume
The reflection coefficients were measured in the frequency domain as S-parameters, over the working frequency span of each TE11 mode microwave probe. It should be noted that: prior to the measurement, the network analyser was calibrated (two-port, SOLT method [33]) in conjunction with the flexible coaxial cable, to compensate for the cable characteristic and the channel delay. A total of 3201 frequency points with equal intervals were sampled over the working frequency span of each microwave probe. Every measurement was conducted 30 times automatically by using the ‘average’ function of the network analyser, and the stabilised average result was recorded. The measured frequency domain signals were converted into the time domain using a fast Fourier transform with a Kaiser window (the shape factor was 6). Furthermore, a signal-processing method [34,35] was employed to compensate for the dispersion of microwaves during propagation and to predict the location of the flaw.
Low-power fully monolithic MICS band receiver for 402-405 MHz implantable devices
Published in International Journal of Electronics, 2020
For the measurement setup and for interfacing the fully differential analog I/Os with 50Ω termination single-ended connections of the network analyzer, a printed circuit board was developed. All parameters were measured by the Agilent 4395A network analyzer with the reflection test kit and E4443A spectrum analyzer. The network analyzer covers a frequency range from 10 Hz to 0.5 GHz. The complete circuit design consumes 3.14 mA from a 1.2 V power supply. A two-tone RF signal was applied at 403.1- and 403.11 MHz and LO power was selected to be −5dBm at 403 MHz. The IIP3 is approximately 2dBm for RF receiver including the VGA and the integrated VCO, as depicted in Figure 15. With the integrated LO frequency designed at 403-MHz, the receiver conversion gain (S21) through the frequency range of operation is shown in Figure 16(a) with a peak gain of 43 dB at 403 MHz. The gain at 403MHz frequency for different power levels of LO signal input to the mixer is shown in Figure 16(b).
Effectively Optimized Dual-band Frequency Selective Surface Design for GSM Shielding Applications
Published in IETE Journal of Research, 2022
B. Döken, Ali Berkay Koç, İhsan Güney Koç, Mikail Altan
The measurement setup is shown in Figure 9. The design's prototype containing 10 × 10 elements was fabricated and measured. Two Vivaldi antennas and Rohde & Schwarz R&S®FSH8 network analyzer were used in the measurement. The network analyzer is calibrated in the 0.52–2.5 GHz frequency band by using thru calibration method. Thus, both the effect of diffraction from the edges of the measuring panel and reflection from the floor and walls on the measurement results is minimized.