Compact Inline E plane Waveguide Resonators and Bandpass Filters with I-shaped Resonant Insets

In this paper, waveguide resonators and bandpass filters with E-plane inserts containing I-shaped resonant insets are presented. These insets introduce to the response finite transmission zeros much less sensitive than those produced by cross-couplings. Also, their use results in structure compactness, unlike bandstop resonant cavities that add volume. Two kinds of extracted pole sections that demonstrate response flexibility of the proposed resonators are designed at 10 GHz and tested. One is based on the dominant mode with a transmission zero in the upper stopband and the other on a pair of higher order modes with a transmission zero in the lower stopband. Also, a 3rd order filter for 11 GHz band combining both dominant and higher order mode resonators is modeled to illustrate the scalability of such a modular design. These filters are very suitable for low-cost mass production

A Fully Planar Substrate Integrated Probe-Based Wideband Orthomode Transducer

This paper introduces a planar orthomode transducer (OMT) using substrate integrated waveguides (SIWs) and substrate integrated coaxial lines (SICLs) that is entirely contained within two substrate layers. SICLs form a quadruplet of probes inside the metal waveguide with fully symmetrical geometry. Such a structure is smaller and lighter than a waveguide OMT, its construction is simpler than of a coaxial OMT, however, isolation and loss properties are less degraded compared to the use of planar unshielded technologies such as microstrip. A new wideband inline SICL to SIW transition has been developed to allow grade separation of SIWs belonging to opposite polarizations through different substrate layers. The designed substrate integrated probe-based OMT on RO4003CTM substrate covers the frequency band from 8.1 to 12.5 GHz with return loss higher than 19 dB, insertion loss less than 1.2 dB, inter-port isolation higher than 62 dB and cross-polarization discrimination higher than 65 dB

Substrate Integrated Coaxial Line Planar Transitions to Single-Layer Transmission Lines and Waveguides

This paper presents inline transitions from substrate integrated coaxial line (SICL) to microstrip line, coplanar waveguide (CPW), as well as substrate integrated waveguide (SIW). A common property is the conversion of transmission medium from double to single substrate layer of PCB. The first two of described transitions can be used from DC up to the presence of higher order modes if the characteristic impedances of two meeting transmission lines are matched. The transition to substrate integrated waveguide is of higher complexity, yet compact. Both sides of the SICL-SIW transition are strongly coupled to resonant cavity, and return loss greater than 20 dB is achieved in fractional bandwidth of 10.91 %. Improvements compared to the existing solutions have been made in designs of all three transitions

Hybrid Manufactured Waveguide Resonators and Filters for mm-Wave Applications

Additive and hybrid manufactured waveguide resonators and bandpass filters for mm-wave applications are presented. A Ka band 3D printed waveguide resonator with inductive windows and 28 GHz 5G band hybrid manufactured waveguide resonator and bandpass filter are designed. Hybrid manufacturing combines 3D polymer printing and conventional metal processing technologies. In order to illustrate the accuracy of the design, a 3D printed waveguide transmission line and resonator with the resonant frequency of 33 GHz are fabricated and tested

Ultra Compact Inline E-Plane Waveguide Bandpass Filters Using Cross Coupling

This paper presents novel ultra-compact waveguide bandpass filters that exhibit pseudo elliptic responses with ability to place transmission zeros on both sides of the passband to form sharp roll offs. The filters contain E plane extracted pole sections cascaded with cross-coupled filtering blocks. Compactness is achieved by the use of evanescent mode sections and closer arranged resonators modified to shrink in size. The filters containing non-resonating nodes are designed by means of the generalized coupling coefficients (GCC) extraction procedure for the cross-coupled filtering blocks and extracted pole sections. We illustrate the performance of the proposed structures through the design examples of a third and a fourth order filters with center frequencies of 9.2 GHz and 10 GHz respectively. The sizes of the proposed structures suitable for fabricating using the low cost E plane waveguide technology are 38% smaller than ones of the E plane extracted pole filter of the same order

Low-Cost Hybrid Manufactured Waveguide Bandpass Filters with 3D Printed Insert Dielectric

In this paper, a new type of simple and inexpensive waveguide filter manufacturing that minimizes material consumption and has capabilities of high performance and rapid prototyping is presented. Filter inserts are fabricated by a combination of additive dielectric manufacturing and subtractive metal manufacturing, whereas standard waveguides are used as housings, utilizing best properties of each technology. Along with it, a suitable filter design using metal rectangular rings has been developed. Since the rings that act as positive reactance discontinuities in the passband are resonant at frequencies below it, it is possible to bring lower stopband transmission zeros near the passband to create sharp skirt. A resonator of such a filter and a third order bandpass filter sample have been designed at 11.13 GHz and 11.36 GHz centre frequencies respectively. In addition, smaller size rectangular rings in waveguide can realize upper stopband transmission zeros while acting as negative reactance discontinuities in the passband. This was utilized in fourth order bandpass filter at 11.36 GHz centre frequency with finite transmission zeros in both stopbands. All the filtering structures have been fabricated with 3D printer to extrude polylactic acid and circuit board plotter to mill copper sheet, and tested. Excellent measurement results that have been obtained validate the proposed design. Practical sides of achieving quality 3D printouts are analysed

Online decentralized decision making with inequality constraints: an ADMM approach

We discuss an online decentralized decision making problem where the agents are coupled with affine inequality constraints. Alternating Direction Method of Multipliers (ADMM) is used as the computation engine and we discuss the convergence of the algorithm in an online setting. To be specific, when decisions have to be made sequentially with a fixed time step, there might not be enough time for the ADMM to converge before the scenario changes and the decision needs to be updated. In this case, a suboptimal solution is employed and we analyze the optimality gap given the convergence condition. Moreover, in many cases, the decision making problem changes gradually over time. We propose a warm-start scheme to accelerate the convergence of ADMM and analyze the benefit of the warm-start. The proposed method is demonstrated in a decentralized multiagent control barrier function problem with simulation

Sources of Variation for Milk Traits in Regions of Vojvodina

The study aimed to investigate different sources of variation for milk traits in dairy cows, in first lactation from three breeding regions of Vojvodina (Srem, Banat and Backa). For research purposes a total of 2767 complete and 305 days records of milk yield (MY), fat yield (FY) and milk fat content (MFC) of Holstein-Friesian (HF, black and red) dairy cows was used. All cows were involved in the official milk recording program in 2013 in Vojvodina. Milk traits were analyzed using the mixed linear model in order to explain total variation with bull-sire as a random effect, region, year of birth and calving season as fixed effects and length of lactation as covariates. The average values of MY, MF and MFC in the first lactation of 305 days were 6053.4 kg of milk, 225.24 kg of milk fat and 3.74% milk fat content. The effects of the bull-sire, calving season, year of birth and breeding region on all investigated milk traits were highly significant (p>0.01) during 305 days, but year of birth for complete records had no significant effect on these parameters (P>0.05)