2018 IEEE MTT-S International Microwave and RF Conference (IMaRC)
Linear tapers are the most common taper which are used for impedance matching networks and also i... more Linear tapers are the most common taper which are used for impedance matching networks and also in the design of filters, power dividers, antennas, etc. Surprisingly, they have not been theoretically characterized in the literature. By using theory of small reflections, the characteristics of linear impedance taper (generalized case) and linear width taper (approximate case) have been analyzed in terms of reflection coefficient and results are compared with characteristics of other tapers which validated the same. It has been found that reflection coefficient response for the linear tapers is very close to exponential taper. Moreover, using linear width taper, a novel linearly tapered coupled-line ultra-broadband bandpass filter is designed which possesses a very compact size of $0.34{\lambda _{{g_0}}} \times 0.26{\lambda _{{g_0}}}$ and wide 10 dB passband of 4.5 to 12 GHz.
2017 Twenty-third National Conference on Communications (NCC), 2017
This paper presents the approximate design equation for iris width calculation of Iris Substrate ... more This paper presents the approximate design equation for iris width calculation of Iris Substrate Integrated Waveguide (SIW) bandpass filter. The design equation has been derived by using curve fitting techniques followed by de-embedding method and it is valid for narrowband band pass filter design; the fractional bandwidth (FBW) should not be more than 10%. A generalized procedure has been presented to calculate the inverter parameters of the iris window. At 60 GHz frequency, the design equation has been developed for its validation. The theoretical and calculated normalized reactance values are in good agreement. An iris SIW bandpass filter at 60 GHz has also been designed using the developed procedure.
IEEE Transactions on Circuits and Systems II: Express Briefs, 2020
This brief presents a novel highly compact ultra-broadband bandpass filter (BPF) using linearly t... more This brief presents a novel highly compact ultra-broadband bandpass filter (BPF) using linearly tapered coupled-microstrip line (LTC-ML) and open loop defected ground structure (OL-DGS). The filter structure consists of a LTC-ML with open-circuited stubs (OCSs) and an OL-DGS etched on the ground. The linearly tapered and tightly coupled microstrip OCS can function as two resonators, and with an associated enhanced coupling structure to OL-DGS, it leads to a very compact three-pole filter. The proposed filter also exhibits a quasi-elliptic function response, where two transmission zeros (TZ) closer to each side of the passband to improve selectivity and one TZ at higher side of the upper stopband, can be observed. An approximate in-line synthesis of the proposed third-order filter with three TZs has also been performed, which shows similar characteristics like the desired response. The simulated and measured results of the filter are in good agreement with each other, showing a wide 10 dB return loss (RL) bandwidth from 4.5 to 12 GHz, insertion loss better than 1.5 dB and group delay variation of lesser than 0.2 ns in the whole passband. Furthermore, it has a very compact size of $0.31\lambda _{g}\times 0.55\lambda _{g}$ at the central frequency of 8.25 GHz.
IEEE Microwave and Wireless Components Letters, 2020
The dispersion diagrams for the proposed spoof surface plasmon polariton (SSPP) unit [1, Fig. 1(b... more The dispersion diagrams for the proposed spoof surface plasmon polariton (SSPP) unit [1, Fig. 1(b)] and the substrate-integrated waveguide (SIW) unit [1, Fig. 1(c)] are plotted in [1, Fig. 2] , which are incorrect and the correct dispersion curves for the same are presented here, as shown in Fig. 1 . The dispersion curves are analyzed and plotted for mode-1 simulation in the eigenmode solver of CST microwave studio. Furthermore, the dispersion curve with optimized dimensions, $L_{i}$ and $W_{i}$ , where $i\in (5,\ldots ,8)$ for the SSPP part [1, Fig. 1(a)] , is shown in Fig. 2 . The lower and upper cutoff frequencies for the passband of the filter are defined from the structural parameters of SIW and SSPP units, respectively. It can be seen from the dispersion curves of SIW and SSPP units [1, Fig. 2] that the lower cutoff frequency obtained from the SIW unit is around 7 GHz, while the upper cutoff frequency obtained from the SSPP unit is around 6 GHz ( $W=15$ mm of the SIW unit and $W=8$ mm of the SSPP unit). However, only the cutoff frequency in the dispersion curve of the SIW unit is correct, from where the lower cutoff frequency of the proposed BPF is set around 7 GHz. The dispersion curve of the SIW unit [1, Fig. 1(c)] with correct distribution trend is shown here in Fig. 1(b) . The passband of the proposed hybrid SSPP-SIW filter is about 7–11 GHz, and hence, the correct upper cutoff frequency for passband of the filter, as it can be seen from our corrected dispersion curve of the SSPP unit [see Fig. 1(a) ], is about 11 GHz. It can also be noted that $p$ is the period of SSPP in our corrected dispersion curves.
International Journal of Microwave Science and Technology, 2015
This paper presents a novel ultrawideband (UWB) bandpass filter using stepped impedance stub load... more This paper presents a novel ultrawideband (UWB) bandpass filter using stepped impedance stub loaded microstrip resonator (SISLMR). The proposed resonator is so formed to allow its four resonant frequencies in the UWB passband, which extends from 3.1 GHz to 10.6 GHz. Moreover, two spurline sections are employed to create a sharp notched-band filter for suppressing the signals of 5 GHz WLAN devices. Experimental results of the fabricated filters are in good agreement with the HFSS simulations and validate the design.
2018 IEEE MTT-S International Microwave and RF Conference (IMaRC)
Linear tapers are the most common taper which are used for impedance matching networks and also i... more Linear tapers are the most common taper which are used for impedance matching networks and also in the design of filters, power dividers, antennas, etc. Surprisingly, they have not been theoretically characterized in the literature. By using theory of small reflections, the characteristics of linear impedance taper (generalized case) and linear width taper (approximate case) have been analyzed in terms of reflection coefficient and results are compared with characteristics of other tapers which validated the same. It has been found that reflection coefficient response for the linear tapers is very close to exponential taper. Moreover, using linear width taper, a novel linearly tapered coupled-line ultra-broadband bandpass filter is designed which possesses a very compact size of $0.34{\lambda _{{g_0}}} \times 0.26{\lambda _{{g_0}}}$ and wide 10 dB passband of 4.5 to 12 GHz.
2017 Twenty-third National Conference on Communications (NCC), 2017
This paper presents the approximate design equation for iris width calculation of Iris Substrate ... more This paper presents the approximate design equation for iris width calculation of Iris Substrate Integrated Waveguide (SIW) bandpass filter. The design equation has been derived by using curve fitting techniques followed by de-embedding method and it is valid for narrowband band pass filter design; the fractional bandwidth (FBW) should not be more than 10%. A generalized procedure has been presented to calculate the inverter parameters of the iris window. At 60 GHz frequency, the design equation has been developed for its validation. The theoretical and calculated normalized reactance values are in good agreement. An iris SIW bandpass filter at 60 GHz has also been designed using the developed procedure.
IEEE Transactions on Circuits and Systems II: Express Briefs, 2020
This brief presents a novel highly compact ultra-broadband bandpass filter (BPF) using linearly t... more This brief presents a novel highly compact ultra-broadband bandpass filter (BPF) using linearly tapered coupled-microstrip line (LTC-ML) and open loop defected ground structure (OL-DGS). The filter structure consists of a LTC-ML with open-circuited stubs (OCSs) and an OL-DGS etched on the ground. The linearly tapered and tightly coupled microstrip OCS can function as two resonators, and with an associated enhanced coupling structure to OL-DGS, it leads to a very compact three-pole filter. The proposed filter also exhibits a quasi-elliptic function response, where two transmission zeros (TZ) closer to each side of the passband to improve selectivity and one TZ at higher side of the upper stopband, can be observed. An approximate in-line synthesis of the proposed third-order filter with three TZs has also been performed, which shows similar characteristics like the desired response. The simulated and measured results of the filter are in good agreement with each other, showing a wide 10 dB return loss (RL) bandwidth from 4.5 to 12 GHz, insertion loss better than 1.5 dB and group delay variation of lesser than 0.2 ns in the whole passband. Furthermore, it has a very compact size of $0.31\lambda _{g}\times 0.55\lambda _{g}$ at the central frequency of 8.25 GHz.
IEEE Microwave and Wireless Components Letters, 2020
The dispersion diagrams for the proposed spoof surface plasmon polariton (SSPP) unit [1, Fig. 1(b... more The dispersion diagrams for the proposed spoof surface plasmon polariton (SSPP) unit [1, Fig. 1(b)] and the substrate-integrated waveguide (SIW) unit [1, Fig. 1(c)] are plotted in [1, Fig. 2] , which are incorrect and the correct dispersion curves for the same are presented here, as shown in Fig. 1 . The dispersion curves are analyzed and plotted for mode-1 simulation in the eigenmode solver of CST microwave studio. Furthermore, the dispersion curve with optimized dimensions, $L_{i}$ and $W_{i}$ , where $i\in (5,\ldots ,8)$ for the SSPP part [1, Fig. 1(a)] , is shown in Fig. 2 . The lower and upper cutoff frequencies for the passband of the filter are defined from the structural parameters of SIW and SSPP units, respectively. It can be seen from the dispersion curves of SIW and SSPP units [1, Fig. 2] that the lower cutoff frequency obtained from the SIW unit is around 7 GHz, while the upper cutoff frequency obtained from the SSPP unit is around 6 GHz ( $W=15$ mm of the SIW unit and $W=8$ mm of the SSPP unit). However, only the cutoff frequency in the dispersion curve of the SIW unit is correct, from where the lower cutoff frequency of the proposed BPF is set around 7 GHz. The dispersion curve of the SIW unit [1, Fig. 1(c)] with correct distribution trend is shown here in Fig. 1(b) . The passband of the proposed hybrid SSPP-SIW filter is about 7–11 GHz, and hence, the correct upper cutoff frequency for passband of the filter, as it can be seen from our corrected dispersion curve of the SSPP unit [see Fig. 1(a) ], is about 11 GHz. It can also be noted that $p$ is the period of SSPP in our corrected dispersion curves.
International Journal of Microwave Science and Technology, 2015
This paper presents a novel ultrawideband (UWB) bandpass filter using stepped impedance stub load... more This paper presents a novel ultrawideband (UWB) bandpass filter using stepped impedance stub loaded microstrip resonator (SISLMR). The proposed resonator is so formed to allow its four resonant frequencies in the UWB passband, which extends from 3.1 GHz to 10.6 GHz. Moreover, two spurline sections are employed to create a sharp notched-band filter for suppressing the signals of 5 GHz WLAN devices. Experimental results of the fabricated filters are in good agreement with the HFSS simulations and validate the design.
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