A new type of transmission-line resonator is proposed. It is composed of a finite-long straight nonreciprocal phase-shift composite right/left handed transmission line, and both terminals are open or shorted. On the c...
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A new type of transmission-line resonator is proposed. It is composed of a finite-long straight nonreciprocal phase-shift composite right/left handed transmission line, and both terminals are open or shorted. On the contrary to conventional transmission-line resonators or traveling-wave resonators, the resonant frequency does not depend on the total size of the resonators, but on the configuration of the unit cells. In addition, field profiles on the resonator are analogous to those of traveling-wave resonators, i.e., uniform magnitude distribution and linearly space-varying phase distribution along the resonator. The spatial gradient of the phase distribution is determined by the nonreciprocal phase constants of the transmission lines. The proposed resonator is specifically designed and fabricated by employing a normally magnetized ferrite microstrip line. The fundamental operations of the proposed resonator are demonstrated.
An improvement in the simulation of the power lines is obtained by adding a negative capacitance in parallel with the series inductances in the π-equivalent circuit *** electric lines and cables paraments are not lum...
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ISBN:
(纸本)9781424455690
An improvement in the simulation of the power lines is obtained by adding a negative capacitance in parallel with the series inductances in the π-equivalent circuit *** electric lines and cables paraments are not lumped, but distributed all over the length of the circuit. Resistances, conductances, capacitances, and inductances are all expressed in Ω/m, /m, F/m, and H/m respectively. However, upon expanding 1/Z' and Y' in terms of the dimensionless variable (γL), where L is the length of the line, one more term leads to a more elaborate equivalent circuit, with an additional negative capacitance in parallel with the Z'.In this paper I will compare the Exact model, Nominal π, and the modified π model using 1. Input Impedance Study 2. Input to Output Voltage Ratio including two case studies 3. Output Voltage Transient Response.
A novel coupled line structure based on two inter-wound right-handed metamaterial transmission lines is investigated. The basic approach is to compress, twist, and fragment (CTF) metal strips or discs periodically in ...
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A novel coupled line structure based on two inter-wound right-handed metamaterial transmission lines is investigated. The basic approach is to compress, twist, and fragment (CTF) metal strips or discs periodically in a multi-layer structure to form a four port structure that carries the feature of a large slow-wave factor with a band selection capability. Dispersion characteristics of both odd and even modes are investigated with emphasis on phase equalization and impedance design. A specific metamaterial couple-lines structure is designed, fabricated and tested as an example. The measured results of the slow-wave factor and line impedance are in good agreement with those of simulated results. Potential applications of the proposed coupled line structure are also discussed.
A novel hybrid ring coupler is proposed for circuit miniaturization in this paper. The coupler is constructed on a substrate of high dielectric constant, and multiple open stubs are connected on the inside of the ring...
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A novel hybrid ring coupler is proposed for circuit miniaturization in this paper. The coupler is constructed on a substrate of high dielectric constant, and multiple open stubs are connected on the inside of the ring for the purpose of size reduction. To achieve high characteristic impedance of the main lines in limited fabrication tolerance, fan-shaped apertures are formed on the ground plane underneath the relative wide micro-strip conductors in the center. The size of the ring coupler is one third of the conventional one, solving the problem that ring coupler area shrink factor can not be very small for substrate of high dielectric constant in many papers. The design method is validated by simulation results.
A bandpass filter using symmetrical Left-Handed (LH) transmission line (TL) Zeroth-Order Resonators (ZOR) is proposed. The symmetrical LH TL is first characterized by the dispersion characteristics of the unit cell an...
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A bandpass filter using symmetrical Left-Handed (LH) transmission line (TL) Zeroth-Order Resonators (ZOR) is proposed. The symmetrical LH TL is first characterized by the dispersion characteristics of the unit cell and its left handedness is verified by the transmission characteristics of 15 cells cascaded LH TL. A symmetrical LH TL open circuited on both sides, acting as a ZOR with shunt resonance, is used as a resonating element in the microstrip end coupled resonator bandpass filter. The open circuited ZOR is characterized by susceptance slope parameter, and bandpass filter is designed using microstrip series gaps as the admittance inverters. Size independent resonance property of the ZOR combined with homogeneity condition of the LH TL unit cell is utilized in the size reduction of bandpass filter. The full wave simulated transmission characteristics of the designed bandpass filter are experimentally verified. They show that size of the filter is greatly reduced (approximately 64%) when compared to a conventional half wavelength coupled bandpass filter.
This paper presents a new circuit model of SSSC based on state equations in three-wired systems. SSSC is a series compensator of FACTS family. It injects an almost sinusoidal voltage with variable amplitude and is equ...
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This paper presents a new circuit model of SSSC based on state equations in three-wired systems. SSSC is a series compensator of FACTS family. It injects an almost sinusoidal voltage with variable amplitude and is equivalent to an inductive or a capacitive reactance in series with the transmission line. The analysis of a power electronics system is complex, owing to its switching behavior. Since such a system has its special complexities, the need for simpler model is essential, though a more practical one is sometimes appropriate. With simple changes, this paper's model shows different states of SSSC, both transient and steady states, in the range of ideal to practical as confirmed by MATLAB simulation. This model is suitable for circuit simulation software such as MATLAB or PSPICE and is proper to control process and control methods. This model can be used as a starting point for further investigations on control methods in the future.
Various studies have been carried out to determine the origin, the development and the effects of very fast transients (VFT) in GIS-Busbars. To date little knowledge exists on how VFT propagate through a high voltage ...
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Various studies have been carried out to determine the origin, the development and the effects of very fast transients (VFT) in GIS-Busbars. To date little knowledge exists on how VFT propagate through a high voltage circuit breaker, when the interrupter itself is the source of the VFT. For the development of circuit breakers it is important to know if these VFT are able to affect the dielectric coordination of the interrupter. In order to determine transient voltages at different locations inside an interrupter unit a numerical model has been derived. The model approach represents the circuit breaker as a system of concatenated transmission lines. The simulations were compared to measurements of a real circuit breaker and prooved the accuracy of the model in the frequency range from 9 kHz up to 500 MHz. This model allows future parameter studies which show the dependence of VFT overvoltages on the geometry of the circuit breaker.
Composite Right/Left Handed Transmission Lines have been used to design Dual-Band/Diplexer distributed amplifiers. The isolation between bands can be improved by designing non-uniform versions of such distributed ampl...
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Composite Right/Left Handed Transmission Lines have been used to design Dual-Band/Diplexer distributed amplifiers. The isolation between bands can be improved by designing non-uniform versions of such distributed amplifiers. In this contribution, an experimental large-signal characterization of three these non-uniform distributed amplifiers is described and discussed. The results obtained suggest that the isolation between bands can be significantly improved without compromising their nonlinear performance.
A low cost, fast yet highly accurate method for determining liquid level inside small containers is described. The non-invasive technique can easily resolve sub-1% levels in vials containing a few ml or less of liquid...
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ISBN:
(纸本)9781424447251
A low cost, fast yet highly accurate method for determining liquid level inside small containers is described. The non-invasive technique can easily resolve sub-1% levels in vials containing a few ml or less of liquid and potentially be an order of magnitude more accurate than capacitive level sensors. The vial is placed inside an electrically conducting holder to guide a radio-frequency wave inside the vial. The holder-vial guide acts like an open circuited transmission line whose reflection coefficient is nominally unity but phase angle is a function of the liquid level. By performing a vector measurement of the reflection coefficient, it is possible to achieve sub-wavelength resolution and therefore measure the level highly accurately. An intentional impedance mismatch between the holder-vial guide and the measurement system can be used enhance the sensitivity to level variations, the optimum sensitivity occurring at multiples of quarter wavelength. The implementation details in the form of a reflectometer and results from an actual level measurement are presented.
This paper presents a broadband Stripline-to-Microstrip transition with constant impedance section. In the transition the structural parameters of transmission line have been used to provide smooth electromagnetic fie...
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ISBN:
(纸本)9781424452880;9781424459148
This paper presents a broadband Stripline-to-Microstrip transition with constant impedance section. In the transition the structural parameters of transmission line have been used to provide smooth electromagnetic field matching together with providing unchanged characteristic impedance along transition section. This solution eliminates the necessity of impedance transformer. The transition enables easy access to stripline circuits situated on the internal layers of multilayer structures by use of typical microstrip terminals. The transition has a simple structure for the ease of fabrication with low cost. The measured performance exhibits flat frequency response over broad bandwidth. The insertion loss is less than 0.5 dB and a return loss is better than 25 dB within frequency range 1 GHz to 10 GHz.
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