диафрагмированные волноводные фильтры / 12a9eaba-3c38-49b4-8249-8a47c20065f6

[5]Nakano Y, Takahei KI, Noguchi Y, et al. 1.5 μm InGaAsP/InP BH lasers on p-type InP substrates. Jpn J Appl Phys. 1980; 19 (10): L612-L614.

[6]Kakimoto S, Takemoto A, Sakakibara Y, Nakajima Y, Fujiwara M. Threshold currents of 1.2-1.55 μm P-substrate buried crescent laser

diodes, IEEE J Quant Electron. 1992; 28 (7): 1631-1635.

[7]Tauber D, Bowers JE. Dynamics of wide bandwidth semiconductor lasers. Int J High Speed Elect Syst. 1997;08(03):377-416.

[8]Winston DW. Physical Simulation of Optoelectronic Semiconductor Devices, PhD thesis, University of Colorado, 1996

[9]Kelly NP, Dernaika M, Caro L, et al. Regrowth-free single mode laser based on dual port multimode interference reflector. IEEE Photonics Technol Lett. 2017; 29: 279-282.

[10]Dernaika M, Caro L, Kelly NP, et al. Deeply etched inner-cavity pit reflector. IEEE Photonics J. 2017; 9: 1-8.

[11]Morrissey PE, Kelly N, Dernaika M, Caro L, Yang H, Peters FH. Coupled cavity single-mode laser based on regrowth-free integrated MMI reflectors. IEEE Photon Technol Lett. 2016;28:1313-1316.

[12]Liu JM. Photonic Devices. Cambridge University Press, Cambridge, UK; 2005:800.

Abstract

Multiband bandpass filter (BPF) design is proposed by utilizing E-plane septa to introduce transmission zeros in-band for waveguide application. Due to the unique employment of E-plane septa, multiband BPF responses are flexible to realize. Since number of transmission zeros is strongly dependent on the structure of employed septa, by adjusting the parameters of septa, dual-band, tri-band, and quad-band, multiband BPF responses are presented. While various multiband responses can be achieved without changing the structure, it is more competitive and compatible. Somehow, tri-band and quadband W-band filters are fabricated for validation of the design technique for multiband BPF applications.

K E Y W O R D S

E-plane septa, multiband, waveguide

How to cite this article: Duggan SP, Yang H, Kelly NP, et al. P-substrate InP-based 1.5 μm lasers using an internal carbon-doped layer to block p- dopant diffusion. Microw Opt Technol Lett. 2018;60: 2363–2367. https://doi.org/10.1002/mop.31364

Received: 15 February 2018

DOI: 10.1002/mop.31394

Multiband bandpass filter design using E-plane septa for waveguide application

1School of Electronic Engineering, University of Electronic Science and Technology of China, Chengdu, China

2Department of Electronic Science, Xiamen University, Xiamen, China

Correspondence

Yonghong Zhang, School of Electronic Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China. Email: zhangyhh@uestc.edu.cn

Funding information

Ministry of Science and Technology of the People’s Republic of China, Grant/Award Number: 2013YQ200503.

1 | INTRODUTION

There is an increasing demand for multiband bandpass filter (BPF) with high performance, easy manufacturing, and excellent compatibility in wireless communication, radar, and satellite applications. Numerous multiband filters have been designed on microstrip,1–5 however, so far there are scarcely any approaches on tri-band or more passbands design with waveguide structure. Using evanescent mode or resonant cavity, dual-band BPFs with large size and expensive fabrication are reported in ref. 6,7 In addition, based on E-plane resonators with a metal wall or double-layer configuration adopted, dual-band BPFs are presented.8,9 While E- plane septa is a crucial item in filter design, it has only been applied to wide bandwidth BPF.10 Moreover, considering the complexity of forming passbands directly, it is more convenient to allocate transmission zeros suitably to the whole band for more passbands.

In this letter, multiband BPF design for waveguide application is proposed, which utilizes E-plane septa to introduce transmission zeros in-band for flexible realization of multiband. By varying dimensions of septa, number and location of transmission zeros can be adjusted. In this way, to the best of our knowledge, it is the first time that dual-band, tri-band, and quad-band multiband BPFs have been designed utilizing the same structure.

2 | DESIGN PROCEDURES

2.1 | E-plane septa structure

The configuration of E-plane septa in waveguide is shown in Figure 1, where gap is etched to divide traditional E-plane

FIGURE 1 Configuration of E-plane septa in waveguide

septa into two independent parts. For one of these two structures, the double resonant cavities can be coupled to each other through septa. Thus not only signal paths, but design freedoms are increased for improving filter passbands and performance.

Figure 2A plots the coupling scheme of proposed multiband BPFs design, where S and L are source/load terminals. While I-IV are four resonator nodes, the solid/dashed line represents main/weak coupling. For simplicity, the highly symmetrical coupling scheme can be investigated by resource/load terminals and one single resonator node whose corresponding response is shown in solid line in Figure 2B. It means that one passband with two transmission zeros located at two sides can be produced by one single node. Two notches in-band are created by the resonator node, apparently, while coupling from source to load has allpass property. Therefore, it is obvious that number of passbands is correlated with number of resonator nodes as shown in Figure 2B. Consequently, there are at least four resonant cavities needed for quad-band design. Since nodes I and III (or nodes II and IV) are symmetrical, transmission zeros caused by nodes I and II can be made to coincide. While node I and node II (or node III and node IV) are also symmetrical, with the coupling of two nodes, resonant frequency will split into two called even and odd modes. Hence, by adjusting these four resonant nodes and their coupling strength, dual-band, tri-band, and quad-band multiband BPFs can be designed with resonant nodes: I-IV.

2.2 | MULTIBAND BPFs DESIGN

Moreover, coupling of these two nodes is directly related with the width of septa, which means transmission zeros can

FIGURE 3 Variation of transmission zeros against W2 for dualband BPF (G1 = G2 = G3 = G4 = 1.4 mm) [Color figure can be viewed at wileyonlinelibrary.com]

be allocated suitably in-band by changing the width of septa. As Figure 3 depicts, double passbands are formed with triple groups of transmission zeros. It is demonstrated that transmission zeros in Figure 4 can be separated into quadruple groups and triple passbands are presented. Meanwhile, Figure 5 shows quintuple groups of transmission zeros that are corresponding to quadruple passbands for multiband application. In this letter, tri-band and quad-band multiband filters are fabricated on Rogers 5880 with dielectric constant of 2.2 and thickness of 0.127 mm as examples to validate the technique.

3 | EXPREMENTAL RESULTS

The photography of proposed tri-band and quad-band BPFs is depicted in Figure 6. The dimensions of tri-band filter are as follows: W1 = W3 = 0.75, W2 = 1.2, W4 = W6 = 1, W5 = 0.95, G1 = G2 = 0.9, G3 = G4 = 1.25, S1 = S2 = 0.1, D1 = D3 = 0.235, D2 = 0.6, all in mm. The measured minimum insertion loss of triple passbands is 1.37 dB,

W2 (mm)

FIGURE 4 Variation of transmission zeros against W2 for triband BPF (G1 = G2 = 0.9 mm, G3 = G4 = 1.25 mm) [Color figure can be viewed at wileyonlinelibrary.com]

0.85 dB, and 0.93 dB with a 3-dB fraction bandwidth of 10.56%, 6.35%, and 5.09%, respectively. Seven transmission zeros are allocated at 79.55, 80.51, 91.80, 100.72, 101.68, 108.68, and 109.80 GHz.

In addition, the dimensions of quad-band filter are shown: W1 = W3 = 0.75, W2 = 1.2, W4 = W6 = 1, W5 = 0.95, G1 = G2 = 1.15, G3 = G4 = 1.25, S1 = S2 = 0.1, D1 = D3 = 0.235, D2 = 0.6, all in mm. The measured minimum insertion loss and 3-dB fraction bandwidth of quadruple passbands multiband BPF are 1.83/1.26/2.38/2.65 dB, and 7.67%/4.25%/3.16%/2.12%, respectively. Eight transmission zeros located at 79.81, 80.95, 89.61, 95.38, 99.23, 103.70, 105.53, and 109.90 GHz are observed.

Simulated and measured results of the proposed two multiband BPFs are shown in Figures 7 and 8, which demonstrates good agreement. Frequency shift and insertion loss deterioration can be seen between the simulation and measurement results. This is because of the fabrication tolerance, assembling and the material errors.

W2 (mm)

FIGURE 6 Photograph of the proposed filters [Color figure can be viewed at wileyonlinelibrary.com]

4 | CONCLUSION

Multiband BPF design utilizing E-plane septa for waveguide application is proposed. Owing to the unique application of septa for introduction of transmission zeros, multiband filter

Frequency (GHz)

FIGURE 7 Simulated and measured results of tri-band multiband BPF [Color figure can be viewed at

Frequency (GHz)

FIGURE 5 Variation of transmission zeros against W2 for quadband BPF (G1 = G2 = 1.15 mm, G3 = G4 = 1.25 mm) [Color figure can be viewed at wileyonlinelibrary.com]

FIGURE 8 Simulated and measured results of quad-band multiband BPF [Color figure can be viewed at wileyonlinelibrary.com]

with more than double passbands can be designed flexibly. Since tri-band and quad-band multiband filters with easy manufacturing and high compatibility are fabricated as examples, this work is more competitive. Due to these merits, it is a good candidate for multiband BPF design.

Received: 15 February 2018

DOI: 10.1002/mop.31393

Design of dual wideband

ACKNOWLEDGMENT

This work was supported in part by the Ministry of Science and Technology of the People’s Republic of China under grant 2013YQ200503.

ORCID

Yonghong Zhang http://orcid.org/0000-0002-5210-873X

Kai Da Xu http://orcid.org/0000-0001-9408-1347

REFERENCES

[1]Pal M, Ghatak R. A distinctive resonance: multiband bandpass filter design techniques using multimode resonators. IEEE Microw Mag. 2015;16(11):36-55.

[2]Li Q, Zhang Y, Feng X, Fan Y. Tri-band filter with multiple transmission zeros and controllable bandwidths. Int J Microw Wireless Techn. 2016;8(1):9-13.

[3]Sarkar P, Ghatak R, Pal M, Poddar DR. A planar compact dual-band bandpass filter using stepped impedance resonator and interdigital capacitor. Int J Microw Wireless Techn. 2013;3(6): 671-674.

[4]Firmansyah T, Praptodiyono S, Pramudyo AS. Hepta-band bandpass filter based on folded cross-loaded stepped impedance resonator. Electron Lett. 2017;53(16):1119-1121.

[5]Zhou K, Zhou C, Wu W. Substrate integrated waveguide dual-band filter with wide-stopband performance. Electron Lett.

2017;53(16):1121-1123.

[6]Macchiarella G, Tamiazzo S. Design techniques for dual-passband filters. IEEE Trans Microw Theory Techn. 2005; 53(11):3265-3271.

[7]Amari S, Bekheit M. A new class of dual-mode dual-band waveguide filters. IEEE Trans Microw Theory Techn. 2008;56(8): 1938-1944.

[8]Jin JY, Lin XQ, Jiang Y, Xue Q. A novel compact E-plane waveguide filter with multiple transmission zeros. IEEE Trans Microw Theory Techn. 2015;63(10):3374-3380.

[9]Jin JY, Lin XQ, Xue Q. A novel dual-band bandpass E-plane filter using compact resonators. IEEE Microw Wireless Compon Lett.

2016;26(7):484-486.

[10]Shih YC, Itoh T. E-plane filters with finite-thickness septa. IEEE Trans Microw Theory Techn. 1983;31(12):1009-1013.

How to cite this article: Li X, Zhang Y, Da Xu K, Wang J, Li S, Fan Y. Multiband bandpass filter design using E-plane septa for waveguide application.

Microw Opt Technol Lett. 2018;60:2367–2370. https://doi.org/10.1002/mop.31394

bandpass filter using stub loaded multi-mode resonators

Elif Gunturkun Sahin2 | Adnan Gorur2

1Department of Electrical and Electronics Engineering, Nevsehir Haci Bektas Veli University, Nevsehir, Turkey

2Department of Electrical and Electronics Engineering, Nigde Omer

Halisdemir University, Nigde, Turkey

Correspondence

Alper Turkeli, Department of Electrical and Electronics Engineering, Nevsehir Haci Bektas Veli University, 50300 Nevsehir, Turkey. Email: alperturkeli@nevsehir.edu.tr

Abstract

In this paper, a novel dual wideband microstrip bandpass filter is proposed. The designed filter is constructed by two different stub loaded resonators located at the upper and bottom sides of the coupling line. The coupling transmission line is also connected to input and output (IO) ports. The upper resonator creates a wide passband, whereas the bottom resonator is used to create two transmission zeros in the passband. Thus, a wide passband can be divided into dual wide passbands. The bottom resonator is also utilized to improve the insertion and return losses in the passband. The designed filter is fabricated and tested in a very good agreement with the simulated results. The measured fractional bandwidths (FBWs) of the passbands are 44.6% and 24.2% at the center frequencies of 3.4 GHz and 5.51 GHz, respectively. The measured insertion losses in the passbands are 0.51 dB and 1.13 dB.

K E Y W O R D S

bandpass filter, dual-band, microstrip, wideband

1 | INTRODUCTION

Microwave filters have an important place in space and satellite applications since they can select and limit RF/microwave signals.1 Among microwave filters, microstrip structures play a significant role due to their advantages such as easy fabrication, design variety, compactness, etc. In addition, according to the communication requirement of short range and high bandwidth, wideband microstrip bandpass