Pseudo-elliptic bandstop filter with 1:2:3 harmonic ratio stubs

By employing open circuited stubs with a length ratio of 1:2:3 separated by three unit elements, it is shown that a pseudo-elliptic frequency response can be obtained with a compact structure. It has an electrical performance comparable to that of a Cauer filter, but is realizable in etched form for very wide bandwidths and very high rates of cutoff.http://www.ietdl.org/ELhb201

Hybrid superelliptic horn

The waveguide horn with elliptic flare has been shown to exhibit superior radiation and impedance properties. In this article, a horn is described that flares with a hybrid superelliptical profile. The radiation patterns in the principal planes are identical up to the -10-dB points.http://www3.interscience.wiley.com/journal/37176/hom

Bandpass filter with stepped impedance subharmonic stubs

Structures with shunt stubs in a subharmonic ratio that realize bandpass performance have limited application due to the inherent problem of fixed transmission zero positions in the stopband. By application of the principle of splitting, the subharmonic stubs into cascades of transmission line sections, structures can be realized that have transmission zeros at arbitrary positions. A bandpass filter employing stepped impedance stubs is developed, and it is shown that moderate bandwidth can be achieved.http://onlinelibrary.wiley.comjournal/10.1002/(ISSN)1098-27602015-12-30hj201

Pseudo-elliptic function bandstop filter with shunt foster sections

Filters with transmission zeros in the stopband have been shown to have superior rates of cutoff. Conventional Cauer filters give excellent performance but are relatively large and not always practically realizable. In this article, the design of a pseudo-elliptic bandstop filter which employs only shunt Foster sections and unit elements is presented. The filter is of the same size as a Chebyshev filter of the same order, but has a performance comparable to a Cauer filter.http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1098-2760hb201

Transmission line filters with harmonic parallel foster sections

Conventional wideband bandstop filters use Cauer prototypes, but become nonrealizable with Kuroda–Levy transforms for bandwidths of 150% or more. Transmission line filters with harmonic stubs have been shown to be realizable at these bandwidths, but have limited performance ranges due to the fixed positions of the transmission zeros. In this article, two structures that use shunt Foster resonators that enable the shift of the transmission zeros are described. Simulated and measured properties show that greatly improved performance can be realized while not adding to the complexity of the structurehttp://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1098-2760hb201

Pseudo-elliptic bandpass filter with subharmonic stubs

A simple bandpass filter that approximates equal ripples in both the pass band and the stopband is described. The filter comprises two stubs, resonant at one-half and one-quarter of the centre frequency, respectively, and a series overlay capacitor. The filter has a performance comparable to that of a third-order elliptic function filter and has a practical bandwidth of 16-34%

Wideband bandpass filter with extremely wide upper stopband

The realization of planar wideband bandpass filters with an extremely wide upper stopband is described. The filter design differs from conventional approaches in which it is based on the choice of a wideband bandstop (BS) filter, to which a number of shunt-shorted stubs are connected at specific nodes; the stubs provide transmission zeros at the origin. Two examples of wideband bandpass filters with extremely wide upper stopbands are presented: filters based on a fifth-order Chebyshev wideband BS filter and a pseudoelliptic function ultra-wideband-BS filter. Relative passbands in excess of 100% are achieved, while the equivalent of at least four harmonic passbands is suppressed.http://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=22hj2018Electrical, Electronic and Computer Engineerin

Engineering training : the ideal and the reality

The mission of the University is presented as the functions of transfer and creation of knowledge, i.e. teaching and research. In this context, the training in engineering is defined as an academic pursuit, and its relation to the profession being the fulfillment of a need is discussed. The ideal engineering training environment is examined in terms of training, faculty, research, interaction with the profession and availability of facilities. The reality of the situations is discussed in terms of the same subjects. The opinion is expressed that students are badly motivated, and make use of incorrect study-methods perpetuated by the wrong methods of teaching. Teaching staff do too little research and the fact that their remuneration cannot compete with industry makes it difficult to find and keep staff. The association that the faculty have with the profession and industry, makes it possible to maintain the present quality of teaching in engineering. Undergraduate laboratory facilities are inadequate because of lack of funds. The solutions to the problems posed are seen as challenges that start with finding new methods of teaching and stimulating excellence in teaching and research. Based on the benefits that industry and the profession can derive from a healthy academic atmosphere, the solution is seen in strong support from industry for the engineering teaching profession.Item was scanned at 300 dpi. Scanner used HP Scanjet 5590Pp. 19-25: Publikasies van die Universiteit van Pretoria (Nuwe Reeks)http://explore.up.ac.za/record=b115295

Wideband bandstop filter with sub-harmonic stubs

The performance of a wideband bandstop transmission line filter employing a series overlay inductor over two stubs resonating at respectively one half and one quarter of the centre frequency, is described. The structure contributes seven transmission zeros to the stopband and the performance compares to that of a Cauer filter. The structure has the advantage of having impedance levels that are readily realizable.http://www.ietdl.org/E

An asymmetrical dual band bandpass filter

A dual band bandpass filter consisting of a cascade of unit elements and shunt connected stepped open and stepped short circuited stubs, is described. The dual passbands can have unequal, asymmetrical width; the stop‐bandwidth between the desired bands and the harmonic upper bands is substantially increased. A prototype filter that finds application in communication systems is developed.http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1098-2760hj2018Electrical, Electronic and Computer Engineerin