Design Parameters of Inhomogeneous Asymmetric Coupled Transmission Lines

El-Deeb, N.A.; Abdallah, Esmat A.; Saleh, M.B.

doi:10.1109/tmtt.1983.1131550

Cited by 15 publications

(2 citation statements)

References 14 publications

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“…The following equations are given in (1)- (6) in [19], and they show the relationship between the normal-mode parameters of an asymmetric coupled line and its distributed-line parameters…”

Section: Appendixmentioning

confidence: 99%

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Generalised capacitive‐loading method for miniaturisation of forward‐wave directional coupled‐line couplers with arbitrary strip impedances and coupling levels

Lee

2016

IET Microwaves, Antennas & Propagation

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This study demonstrates a capacitive reactive loading method for forward‐wave couplers based on coupled lines. With the method, a miniaturised forward‐wave coupler can be designed by loading either a symmetric or an asymmetric coupled line with shunt capacitors symmetrically or asymmetrically. The method is a generalised version of all previous shunt capacitive loading methods for miniaturisation of forward‐wave coupled‐line couplers since it provides complete control of not only the maximum coupling level, but also the impedances of the two strips. For the first time, a forward‐wave coupled‐line coupler is demonstrated that provides an arbitrary maximum coupling level based on 50‐Ω lines. Therefore, lengthy and/or complicated impedance matching networks can be eliminated, a more effective miniaturisation is enabled, and performance degradation associated with the additional circuitry is minimised. Experimental results of various forward‐wave couplers based on quasi‐symmetric and asymmetric coupled lines with various coupling levels and strip impedances are provided to demonstrate the versatility of the proposed method.

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“…The following equations are given in (1)- (6) in [19], and they show the relationship between the normal-mode parameters of an asymmetric coupled line and its distributed-line parameters…”

Section: Appendixmentioning

confidence: 99%

“…The relationship between the two sets of parameters is given by (8)- (13) in Appendix [19]. Based on the relationship, the normal-mode parameters can be calculated from the distributed-line parameters and vice versa.…”

Section: Introductionmentioning

confidence: 99%

Generalised capacitive‐loading method for miniaturisation of forward‐wave directional coupled‐line couplers with arbitrary strip impedances and coupling levels

Lee

2016

IET Microwaves, Antennas & Propagation

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Planar Coupled Transmission Lines

2021

Introduction to Modern Planar Transmission Lines

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Design of triple‐band filters by using asymmetric parallel‐coupled lines

Zhao

Cui

2008

Micro & Optical Tech Letters

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In [7], the proposed E-shaped microstrip patch antenna works on basis mode with a broadside radiation pattern, which is current on the surface of the patch has been shown in Figure 2. In this article, a novel high-order mode E-shape broadband microstrip patch antenna, in which current distribution is shown in Figure 3, is introduced to work on high-order mode with divided pattern. MEASUREMENT RESULTThe size of the E-shape broadband microstrip antenna is as follows: WS ϭ 7.0 mm, LS ϭ 10.5 mm, WA ϭ 0.5 mm, WL ϭ 15 mm, LL ϭ 20 mm, WI ϭ 0.5 mm, WN ϭ 7.2 mm, and WO ϭ 0.5 mm.The blank rectangles are the microelectro mechanical system switches (MEMS). The height of the substrate is 1.5 mm. The dielectric constant is 2.5. Figure 3 shows the measured return loss of the proposed reconfigurable E-shape broadband microstrip antenna. When all of the MEMS open, the antenna operates at mode 1. The antenna operates at mode 2 with all of the MEMS closed. The measured return loss of the mode 1 E-shape broadband microstrip antenna has a 2:1 VSWR 10.5-15.00 GHz corresponding to 35.3% at the central frequency 12.75 GHz. The mode 2 E-shape broadband microstrip antenna has a 2:1 VSWR 10.8 -14.00 GHz. Two modes share common frequencies from 10.8 to 14.00 GHz corresponding to 28.5% at the central frequency 12.25 GHz. As one would expect, the frequency responses of the two modes are nearly identical. But the simulation and measured results shows that the reconfigurable radiation pattern band is just from 10.8 to 13.2 GHz, which is smaller than the impedance band, because the high-order E-shape microstrip antenna has the lower efficiency at upper frequencies. Figure 4 displays the radiation patterns at 10.8, 12.25, 13.2 GHz in E-plane. The patterns are complementary with each other in each picture. The highest gain is 4.9 dBi at 10.8 GHz.From Figure 4(a), we can see that the 3-dB beam-width is over 140°, and the gain more than 4.0 dBi appears from Ϫ54°to 53°. Similarly, the highest gain is 5.75 dBi at 12.25 GHz. From Figure 4(b), we can see that the 3-dB beam-width is over 128°, and the gain more than 4 dBi appears from Ϫ56 to 3 and 23-56°, from Ϫ3°to 23°the antenna gain is more than 3.2 dBi. The highest gain is 5.2 dBi at 13.20 GHz. From the Figure 4(c), we can see that the 3-dB beam-width is over 100°, and the gain more than 2 dBi appears from Ϫ53 to 22 and 33°-46°, from 22°to 33°the antenna gain is more than 1.7 dBi. So the types of reconfigurable antennas could be used in the places where wide-beam and high gain together is needed such as GPS system, mobile terminal, or wideangle scanning phased array. CONCLUSIONThis article presents a novel E-shape pattern reconfigurable structure for microstrip antenna. The antennas' operate-modes can be changed with MEMS switches. The antenna pattern can be transformed between two situations. The two patterns compensating each other cover more wide rage. It is important to make widebeam radiation patterns and high gain of microstrip antennas, which can be used in GPS, mobile terminal, or wide-angle...

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Design Parameters of Inhomogeneous Asymmetric Coupled Transmission Lines

Cited by 15 publications

References 14 publications

Generalised capacitive‐loading method for miniaturisation of forward‐wave directional coupled‐line couplers with arbitrary strip impedances and coupling levels

Generalised capacitive‐loading method for miniaturisation of forward‐wave directional coupled‐line couplers with arbitrary strip impedances and coupling levels

Planar Coupled Transmission Lines

Design of triple‐band filters by using asymmetric parallel‐coupled lines

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