Reactively-loaded non-periodic slow-wave artificial transmission lines for stop band bandwidth enhancement: application to power splitters

AbstractThis paper presents slow-wave transmission lines based on non-periodic reactive loading. Specifically, the loading elements are stepped impedance shunt stubs (SISS). By sacrificing periodicity using SISS tuned to different frequencies, multiple transmission zeros above the pass band arise, and the rejection level and bandwidth of the stop band is improved as compared with those of periodic structures. Through a proper design, it is possible to achieve compact lines, simultaneously providing the required electrical length and characteristic impedance at the design frequency (dictated by specifications), and efficiently filtering the response at higher frequencies. These lines are applied to the design of a compact power splitter with filtering capability in this work. The length of the splitter, based on a 35.35 Ω impedance inverter, is reduced by a factor of roughly two. Moreover, harmonic suppression better than 20 dB up to the fourth harmonic is achieved.

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Calculation of the Characteristic Impedance of Transmission Lines with Periodic Structures

Journal of the Korea Academia-Industrial cooperation Society ◽

10.5762/kais.2010.11.7.2541 ◽

2010 ◽

Vol 11 (7) ◽

pp. 2541-2548

Author(s):

Jong-Sik Lim ◽

Jae-Hoon Lee ◽

Jun Lee ◽

Sang-Min Han ◽

Dal Ahn

Keyword(s):

Transmission Lines ◽

Periodic Structures ◽

Characteristic Impedance

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Compact power splitter with harmonic suppression based on inductively loaded slow-wave transmission lines

Microwave and Optical Technology Letters ◽

10.1002/mop.31181 ◽

2018 ◽

Vol 60 (6) ◽

pp. 1464-1468 ◽

Cited By ~ 6

Author(s):

J. Selga ◽

J. Coromina ◽

P. Vélez ◽

A. Fernández-Prieto ◽

A. J. Martinez-Ros ◽

...

Keyword(s):

Slow Wave ◽

Transmission Lines ◽

Wave Transmission ◽

Harmonic Suppression ◽

Power Splitter

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Size reduction and harmonic suppression in branch line couplers implemented by means of capacitively loaded slow-wave transmission lines

Microwave and Optical Technology Letters ◽

10.1002/mop.30837 ◽

2017 ◽

Vol 59 (11) ◽

pp. 2822-2830 ◽

Cited By ~ 7

Author(s):

Jan Coromina ◽

Jordi Selga ◽

Paris Vélez ◽

Jordi Bonache ◽

Ferran Martín

Keyword(s):

Slow Wave ◽

Transmission Lines ◽

Wave Transmission ◽

Size Reduction ◽

Harmonic Suppression ◽

Branch Line

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Slow-wave coplanar waveguides based on inductive and capacitive loading and application to compact and harmonic suppressed power splitters

International Journal of Microwave and Wireless Technologies ◽

10.1017/s1759078717001350 ◽

2017 ◽

Vol 10 (5-6) ◽

pp. 530-537 ◽

Cited By ~ 3

Author(s):

Francisco Aznar-Ballesta ◽

Jordi Selga ◽

Paris Vélez ◽

Armando Fernández-Prieto ◽

Jan Coromina ◽

...

Keyword(s):

Slow Wave ◽

Coplanar Waveguide ◽

Ground Plane ◽

Power Splitting ◽

Harmonic Suppression ◽

Power Splitters ◽

Central Strip ◽

Shunt Capacitors ◽

Capacitive Loading ◽

First Time

In this paper, a slow-wave transmission line implemented in coplanar waveguide technology, based on simultaneous inductive and capacitive loading, is presented for the first time. The shunt capacitors are achieved by periodically etching transverse strips in the back substrate side, connected to the central strip through metallic vias. The series inductors are implemented by etching rectangular slots in the ground plane. The effect of these reactive elements is an enhancement of the effective shunt capacitance and series inductance of the line, leading to a significant reduction of the phase velocity (slow-wave effect). Consequently, the guided wavelength is also reduced, and these lines can be applied to the miniaturization of microwave components. Moreover, due to periodicity, these artificial lines exhibit stop bands (Bragg effect) useful for spurious or harmonic suppression. A compact harmonic suppressed power splitter, based on a slow wave 35.35 Ω impedance inverter, has been designed and fabricated in order to demonstrate the potential of the proposed approach. The length of the inverter is 48% the length of the conventional counterpart, and measured power splitting at the first (3f0) and second (5f0) harmonic frequencies is rejected more than 49 and 23 dB, respectively.

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Attenuation Coefficients Prediction for Reflection Layers of Solidly Mounted Resonators via Phononic Band Structures

Volume 13: Nano-Manufacturing Technology; and Micro and Nano Systems, Parts A and B ◽

10.1115/imece2008-67282 ◽

2008 ◽

Author(s):

Chien-Hou Liu ◽

Yuan-Fang Chou

Keyword(s):

Band Gap ◽

Attenuation Coefficient ◽

Periodic Structures ◽

Characteristic Impedance ◽

Phononic Crystal ◽

Stop Band ◽

Density Ratio ◽

Phononic Crystals ◽

Band Structures ◽

Attenuation Coefficients

The solidly mounted resonator (SMR) is one of the major focuses in filter research because it can be used in the frequency above GHz range. The reflection structure composed of periodic layers is vital to the performance of this type of resonator due to its capability in confining acoustic energy in the piezoelectric layer. Therefore the design of reflection layers is a key issue in the development of SMRs. The performance of reflection layers is revealed by the attenuation coefficient that governs the energy distribution in the periodic structures. The behavior of waves propagate in the finite periodic structures are solved by transfer matrix method while the Hill’s method is employed to find the exact solutions in the corresponding phononic crystal. By comparing their displacement fields, it is observed that the attenuation coefficients of infinite and finite periodic structures are almost identical provided the number of layers is adequate. Therefore referring the design of reflection layers to the band structures of the corresponding phononic crystals is reasonable although the attenuation coefficient of a finite periodic structure can not be calculated directly. For one dimensional phononic crystals, the attenuation coefficient becomes larger as the first band gap gets wider. Moreover, the characteristic impedance ratio and density ratio between two interlaced materials increase simultaneously; the first band gap width also increases. This character can be adopted as a guideline in the design of solidly mounted resonators. Based on this guideline, Al and W are chosen as materials for the reflection structure. By calculating its electric impedance, the resonant frequency is found to be the same as the center frequency of first band gap of the corresponding phononic crystal. It shows that employing this stop band character to design the reflection structure of SMR is adequate and efficient.

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Transmission lines characteristic impedance versus Q-factor in CMOS technology

International Journal of Microwave and Wireless Technologies ◽

10.1017/s175907872100060x ◽

2021 ◽

pp. 1-6

Author(s):

Johannes J.P. Venter ◽

Anne-Laure Franc ◽

Tinus Stander ◽

Philippe Ferrari

Keyword(s):

Transmission Line ◽

Slow Wave ◽

Transmission Lines ◽

Characteristic Impedance ◽

Ground Plane ◽

Cmos Technology ◽

Wave Transmission ◽

60 Ghz ◽

Q Factor ◽

Chip Area

Abstract This paper presents a systematic comparison of the relationship between transmission line characteristic impedance and Q-factor of CPW, slow-wave CPW, microstrip, and slow-wave microstrip in the same CMOS back-end-of-line process. It is found that the characteristic impedance for optimal Q-factor depends on the ground-to-ground spacing of the slow-wave transmission line. Although the media are shown to be similar from a mode of propagation point of view, the 60-GHz optimal Q-factor for slow-wave transmission lines is achieved when the characteristic impedance is ≈23 Ω for slow-wave CPWs and ≈43 Ω for slow-wave microstrip lines, with Q-factor increasing for wider ground plane gaps. Moreover, it is shown that slow-wave CPW is found to have a 12% higher optimal Q-factor than slow-wave microstrip for a similar chip area. The data presented here may be used in selecting Z0 values for S-MS and S-CPW passives in CMOS that maximize transmission line Q-factors.

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Design of K-band modified hairpin filter with harmonic suppression using GaAs MMIC process

Circuit World ◽

10.1108/cw-01-2019-0006 ◽

2019 ◽

Vol 45 (4) ◽

pp. 287-291

Author(s):

Jin Guan ◽

Min Gong ◽

Bo Gao ◽

Yuxi Lu ◽

Yu Lu

Keyword(s):

Transmission Lines ◽

Integrated Circuit ◽

Second Harmonic ◽

Simulation Software ◽

Pass Band ◽

Harmonic Suppression ◽

Content Type ◽

Compact Size ◽

Better Than ◽

K Band

Purpose The purpose of this paper is to present a K-band modified hairpin bandpass filter on a planar circuit with harmonic suppression and compact size. Design/methodology/approach The inter-connect transmission lines of conventional hairpin filter are replayed by T-shaped open stub to achieve transmission zero for second harmonic. This filter is simulated and optimized by using electromagnetic simulation software and tested on-chip. Findings This proposed filter shows the return loss of better than −10dB, the insertion loss of better than 2 dB in pass-band and suppression of more than 40 dB at second harmonic. Originality/value The proposed filter can be designed on monolithic microwave integrated circuit, PCB or LTCC and it is useable for microwave and microwave and millimeter-wave systems.

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