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We have developed a microwave measurement system using optical fiber link transceivers for vector network analyzer (VNA). Our proposed system can extend the port of vector network analyzer using optical devices and optical fibers. Further, it can measure S-parameters in full 2-port calibration up to 4GHz. The dynamic range of S21 is found to be more than 100 dB using direct access port of VNA.
The 8 GeV accumulation ring and the 30 GeV × 30 GeV main ring of TRISTAN, an accelerator-storage ring complex at KEK, are controlled by a single computer system. About twenty minicomputers (Hitachi HIDIC 80-E's) are linked to each other by optical fiber cables to form an N-to-N token-passing ring network of 10 Mbps transmission speed. The software system is based on the NODAL interpreter developed...
We propose an antenna gain pattern estimation method for broad band antennas. We have already reported a method for estimating the far field gain using an amplitude center modified Friis transmission formula. This equation can estimate the far field gain using near field S21(ω) measurement for two difference antenna distance. In this paper, we propose a far field gain pattern estimation method using...
We are developing a far field gain and antenna factor estimation method for broadband antenna standards. We have already proposed a method for estimating the free space antenna factor of broadband antennas using a time-domain analysis and a pulse compression technique. However to estimate the antenna factor and gain, we are using fixed antenna distance. In this paper, we propose a new estimation method...
We are developing a far field gain and an antenna factor estimation method for EMI broadband antennas using the amplitude center distance and time frequency analysis technique. Our method is using an amplitude center modified Friis transmission formula. In this paper, we show the measurement results of far field antenna factor of log-periodic dipole array antenna on an open area test site. In the...
Uncertainty budget is evaluated on a frequency response measurement system of PDs using heterodyne technique. The extended uncertainty is calculated as ±0.342 dB at 10 GHz.
The objective of this paper is to show a methodology to estimate transmission line parameters. The method is applied in a single-phase transmission line using the method of least squares. In this method the longitudinal and transversal parameters of the line are obtained as a function of a set of measurements of currents and voltages (as well as their derivatives with respect to time) at the terminals...
The phases of a transmission line are tightly coupled due to mutual impedances and admittances of the line. One way to accomplish the calculations of currents and voltages in multi-phase lines consists in representing them in modal domain, where its n coupled phases are represented by their n propagation modes. The separation line in their modes of propagation is through the use of a modal transformation...
Modal analysis is widely approached in the classic theory of transmission line modeling. This technique is applied to model the three-phase representation of conventional electric systems taking into account their self and mutual electrical parameters. However the methodology has some particularities and inaccuracies for specific applications which are not clearly described in the basic references...
In this article, it is represented by state variables phase a transmission line which parameters are considered frequency independently and frequency dependent. Based on previous analyses, it is used the reasonable number of π circuits and the number of blocks composed by parallel resistor and inductor for reduction of numerical oscillations. It is analyzed the influence of the increase of the RL...
This paper presents a method for analyzing electromagnetic transients using real transformation matrices in three-phase systems considering the presence of ground wires. So, for the Z and Y matrices that represent the transmission line, the characteristics of ground wires are not implied in the values related to the phases. A first approach uses a real transformation matrix for the entire frequency...
A transmission line digital model is developed direct in the phase and time domains. The successive modal transformations considered in the three-phase representation are simplified and then the proposed model can be easily applied to several operation condition based only on the previous knowing of the line parameters, without a thorough theoretical knowledge of modal analysis. The proposed model...
The results presented in this paper are based on a research about the application of approximated transformation matrices for electromagnetic transient analyses and simulations in transmission lines. Initially, it has developed the application of a single real transformation matrix for a double three-phase transmission lines, because the symmetry of the distribution of the phase conductors and the...
This paper describes a computational model based on lumped elements for the mutual coupling between phases in three-phase transmission lines without the explicit use of modal transformation matrices. The self and mutual parameters and the coupling between phases are modeled using modal transformation techniques. The modal representation is developed from the intrinsic consideration of the modal transformation...
This article shows an analysis of the longitudinal electric parameters of a three-phase transmission line/section using a 280-meter high steel tower. This characteristic, the height of the line conductors and distance between them, are intrinsic related to the longitudinal and transversal parameters of the line. By this means, an accurate study was carried out in order to show the electric variations...
In this article, it is represented by state variables phase a transmission line which parameters are considered frequency independently and frequency dependent. It is analyzed what is the reasonable number of π circuits and the number of blocks composed by parallel resistor and inductor in parallel for reduction of numerical oscillations. It is simulated the numerical routine with and without the...
The objective of this paper is to show a methodology to estimate the longitudinal parameters of transmission lines. The method is based on the modal analysis theory and developed from the currents and voltages measured at the sending and receiving ends of the line. Another proposal is to estimate the line impedance in function of the real-time load apparent power and power factor. The procedure is...
This article shows an analysis of the electrical parameters of a three-phase transmission line section using a relatively new design for steel towers characterized by 280 meters high. These main features, the height of the line conductors and distance between them, are intrinsically related to the longitudinal and transversal parameters of the line. By this means, an analysis was carried out in order...
The phases of a transmission line are tightly coupled due to mutual impedances and admittances of the line. One way to accomplish the calculations of currents and voltages in multi-phase lines consists in representing them in modal domain, where its n coupled phases are represented by their n propagation modes. The separation line in their modes of propagation is through the use of a modal transformation...
The authors developed the optical transceiver operating up to 18 GHz and conducted the site VSWR measurement using the optical measurement system. Compared with the coaxial cable system and the optical transceiver system, the SNR of the coaxial cable system was insufficient and incapable of measuring the site VSWR above 7 GHz. On the other hand, the optical transceiver system has more than 50 dB SNR...
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