scholarly journals Enhancement of corona discharge thresholds in microstrip bandpass filters by using cover-ended resonators

Author(s):  
Aitor Morales-Hernández ◽  
Miguel Á. Sánchez-Soriano ◽  
Stephan Marini ◽  
Marta S. Reglero ◽  
Laura Esteve ◽  
...  

Abstract This paper studies the corona discharge power thresholds in microstrip bandpass filters (BPFs) and, in particular, is focused on a solution based on λ/2 cover-ended resonators to enhance their peak power handling capability (PPHC). First, a parametric analysis is carried out to evaluate the variation of the maximum electric field and the unloaded quality factor (Q u ) as a function of the cover's geometrical dimensions (i.e. height, length, and width). Next, several microstrip BPFs centered at 1.6 GHz are designed, and their behaviors under moderate-to-high applied RF power signals are simulated to corroborate the previous study. A suitable number and size of covers are selected to enhance PPHC without barely degrading the filters’ electrical performance and, consequently, without hardly increasing the insertion losses. Finally, two third-order filters with covers and without covers (benchmark prototype) are manufactured, by way of illustration, and they are tested in the European High-Power RF Space Laboratory to validate the good performance of the proposed solution, where a PPHC enhancement of 3.1 dB at high pressures is achieved as compared to the benchmark prototype.

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Sarika Singh ◽  
Sandeep K. Arya ◽  
Shelly Singla

AbstractA scheme to suppress nonlinear intermodulation distortion in microwave photonic (MWP) link is proposed by using polarizers to compensate inherent non-linear behavior of dual-electrode Mach-Zehnder modulator (DE-MZM). Insertion losses and extinction ratio have also been considered. Simulation results depict that spurious free dynamic range (SFDR) of proposed link reaches to 130.743 dB.Hz2/3. A suppression of 41 dB in third order intermodulation distortions and an improvement of 15.3 dB is reported when compared with the conventional link. In addition, an electrical spectrum at different polarization angles is extracted and 79^\circ is found to be optimum value of polarization angle.


2019 ◽  
Vol 97 (1) ◽  
pp. 114-116 ◽  
Author(s):  
A. Dwivedi

Expressions have been obtained for the volume derivatives of the Grüneisen parameter, which is directly related to the thermal and elastic properties of materials at high temperatures and high pressures. The higher order Grüneisen parameters are expressed in terms of the volume derivatives, and evaluated in the limit of infinite pressure. The results, that at extreme compression the third-order Grüneisen parameter remains finite and the fourth-order Grüneisen parameter tends to zero, have been used to derive a fundamental theorem according to which the volume derivatives of the Grüneisen parameter of different orders, all become zero in the limit of infinite pressure. However, the ratios of these derivatives remain finite at extreme compression. The formula due to Al’tshuler and used by Dorogokupets and Oganov for interpolating the Grüneisen parameter at intermediate compressions has been found to satisfy the boundary condition at infinite pressure obtained in the present study.


1994 ◽  
Vol 47 (6) ◽  
pp. 795 ◽  
Author(s):  
HB Senin ◽  
HAA Sidek ◽  
GA Saunders

The elastic and nonlinear acoustic vibrational properties of terbium metaphosphate glasses (Tb2O3)x(P2O5)1?x with x = 0�226,0�247,0�263 and 0�271 (x is the mole fraction) have been determined from measurements of the effects of temperature, hydrostatic pressure, and uniaxial stress on' ultrasonic wave velocity. At temperatures below about 140 K, the elastic stiffness of' (Tb2O3)x(P2O5)1?x glasses becomes anomalously dependent upon temperature, a behaviour usually associated with interactions between acoustic phonons and two-level systems. Except for the (Tb2O3)0�271(P205)0�729 glass, the hydrostatic pressure derivatives of the elastic stiffness and also of the bulk modulus BS of terbium metaphosphate glasses are small and negative. The third-order elastic stiffness tensor components CIJK of the (Tb2O3)0�247(P2O5)0�753 glass between 77 K and 400 K have also been determined. At room temperature, C112, C123 and C144 are positive while C111, C155 and C456 are negative. Both longitudinal and shear acoustic mode Gr�neisen parameters are small and negative: the application of pressure softens the long-wavelength acoustic phonon mode frequencies. The mode softening is enhanced as the temperature is reduced.


2012 ◽  
Vol 2012 (1) ◽  
pp. 000192-000199
Author(s):  
S T Riches ◽  
C Johnston ◽  
A Lui

The requirement to install electronic power and control systems in high temperature environments in aero-engines and in down-well exploration has posed a challenge to the traditional limit of 125°C of electronics systems. The leap in operating temperature to above 200°C in combination with high pressures, vibrations and potentially corrosive environments means that different semiconductors, passives, circuit boards and assembly processes will be needed to fulfil target performance specifications. Silicon on Insulator (SOI) device technology has been shown to be capable of functioning satisfactorily at operating temperatures of >200°C. Most of the applications to date have required performance for short times (<2,000 hours) at the highest operating temperatures of up to 225°C in down-well drilling applications. There is interest in extending the endurance of high temperature electronics into aero-engine and other applications where a minimum 20 year operating life is stipulated. Most of the reliability data on the high temperature endurance of the integrated circuit is generated with little consideration of the packaging technologies, whilst most of the reliability data pertinent to high temperature packaging technologies uses test pieces, which limits any conclusions relating to long term electrical performance. This paper will present results of studies on high temperature packaging technologies relevant to signal conditioning and processing functions for sensors in down-well and aero-engine applications. Different die attach and wire bond options have been included in the study and the performance of several functional blocks on a high temperature SOI device has been tracked over the endurance tests which have lasted for >11,000 hours at 250°C. Degradation phenomena such as thermal migration and material deterioration due to high temperature exposure in air and inert atmospheres will be described. An assessment of the availability of high temperature materials and components to meet long term requirements for operation at 250°C will be presented.


2011 ◽  
Vol 65-66 ◽  
pp. 219-225 ◽  
Author(s):  
Francesco Solazzi ◽  
Cristiano Palego ◽  
Subrata Halder ◽  
James C.M. Hwang ◽  
Alessandro Faes ◽  
...  

2018 ◽  
Vol 10 (8) ◽  
pp. 891-895 ◽  
Author(s):  
Lin-Ping Feng ◽  
Lei Zhu

AbstractIn this paper, a novel class of balun bandpass filters is presented on slot-line resonator (SLR) toward intrinsic balanced performance in amplitude and phase. The proposed balun filter consists of three inductive-coupled SLRs in the middle, one single-ended unbalanced port, and one balanced port with two terminals. According to the distinct field conversion from the slotline to the microstrip feeding line, good balanced performance in amplitude, and phase performance can be intrinsically realized over a wide frequency range. To validate the proposed technique, a prototype third-order balun filter is designed, fabricated, and measured. Both the simulated and measured results have demonstrated that the proposed balun filter can not only achieve good frequency selectivity but also exhibit intrinsic balanced performance in amplitude and phase.


Sign in / Sign up

Export Citation Format

Share Document