Design of compact frequency agile filter-antenna using reconfigurable ring resonator bandpass filter for future cognitive radios

2018 ◽  
Vol 10 (4) ◽  
pp. 487-496 ◽  
Author(s):  
Hany A. Atallah ◽  
Adel B. Abdel-Rahman ◽  
Kuniaki Yoshitomi ◽  
Ramesh K. Pokharel

AbstractIn this paper, a new miniaturized frequency agile filter-antenna with a wide reconfigurable frequency band is proposed for interweave cognitive radios (CRs). A tunable bandpass filter (BPF) composed of a symmetrical ring resonator is cascaded to the feed line of an ultra-wideband planar antenna. The structure of the proposed ring resonator BPF is simple and compact so that the total size of the proposed filter-antenna is smaller than that of a conventional system made of a separate antenna and BPF. The reconfigurability of the proposed filter-antenna is achieved by changing the operating frequency of the BPF by loading the ring resonator with a single varactor diode at its center. The fabricated prototype has successfully achieved a wide operational bandwidth of 1.43 GHz which covers continuous narrow bands from 4.65 to 6.08 GHz. Moreover, the operating tunable narrow bands have stable radiation characteristics. Good agreement between measurement and simulation results is demonstrated.

Frequenz ◽  
2018 ◽  
Vol 72 (5-6) ◽  
pp. 245-252 ◽  
Author(s):  
Maryam Kazemi ◽  
Saeedeh Lotfi ◽  
Hesam Siahkamari ◽  
Mahmood Mohammadpanah

AbstractAn ultra-wideband (UWB) bandpass filter with ultra-wide stopband based on a rectangular ring resonator is presented. The filter is designed for the operational frequency band from 4.10 GHz to 10.80 GHz with an ultra-wide stopband from 11.23 GHz to 40 GHz. The even and odd equivalent circuits are used to achieve a suitable analysis of the proposed filter performance. To verify the design and analysis, the proposed bandpass filter is simulated using full-wave EM simulator Advanced Design System and fabricated on a 20mil thick Rogers_RO4003 substrate with relative permittivity of 3.38 and a loss tangent of 0.0021. The proposed filter behavior is investigated and simulation results are in good agreement with measurement results.


2016 ◽  
Vol 9 (5) ◽  
pp. 1029-1035 ◽  
Author(s):  
Jugul Kishor ◽  
Binod K. Kanaujia ◽  
Santanu Dwari ◽  
Ashwani Kumar

Synthesis of differential-mode bandpass filter (BPF) with good common-mode suppression has been described and demonstrated on the basis of ring dielectric resonator (RDR) for high-performance communication system. A RDR with two pairs of feeding lines has been used to excite TE01δ-mode. This unique combination of feeding lines and the ring resonator creates a differential passband. Meanwhile, TM01δ-mode of the DR can also be excited to achieve common-mode rejection in the stopband. Transmission zeros are created in the lower and upper stopband to further improve the selectivity of the proposed BPF. A second-order differential BPF is designed, fabricated and its performance is measured to validate the concept. There is good agreement between simulated and measured results.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
A. H. Ramadan ◽  
J. Costantine ◽  
Y. Tawk ◽  
C. G. Christodoulou ◽  
K. Y. Kabalan

Frequency-tunable microstrip antennas, for cognitive radio applications, are proposed herein. The approach is based on tuning the operating frequency of a bandpass filter that is incorporated into a wideband antenna. The integration of an open loop resonator- (OLR-) based adjustable bandpass filter into a wideband antenna to transform it into a tunable filter-antenna is presented. The same technique is employed to design a cognitive radio pattern diversity tunable filter-antenna. A good agreement between the simulated and measured results for the fabricated prototypes is obtained. The radiation characteristics of each designed tunable filter-antenna are included herein.


Frequenz ◽  
2016 ◽  
Vol 70 (1-2) ◽  
Author(s):  
Jin Xu

AbstractThis paper presents a novel second-order dual-band bandpass filter (BPF) by using proposed stubs loaded ring resonator. The resonant behavior of proposed stubs loaded ring resonator is analyzed by even-/odd-mode method, which shows its multiple-mode resonant characteristic. Parameters sweep is done so as to give the design guidelines. As an example, a second-order dual-band BPF operating at 1.8/5.2 GHz for GSM and WLAN applications is designed, fabricated and measured. The fabricated filter has a very compact size of 0.05λg×0.15λg. Measured results also show that the proposed dual-band BPF has a better than 20 dB rejection upper stopband from 5.47 GHz to 12.56 GHz. Good agreement is shown between the simulated and measured results.


Frequenz ◽  
2018 ◽  
Vol 72 (7-8) ◽  
pp. 381-384
Author(s):  
Hao Zhang ◽  
Wei Kang ◽  
Wen Wu

Abstract A compact balanced bandpass filter (BPF) based on complementary split ring resonator (CSRR) -loaded substrate integrated waveguide (SIW) structure is reported in this paper. Both TE102 and TE201 modes of the SIW cavity can be excited under differential-mode (DM) operation with the proper positions of the balanced feeds. Meanwhile, the CSRR etched on the top layer of the substrate can also be excited by the axial electric excitation. Then, three transmission poles and two transmission zeros (TZs) have been obtained which improve the selectivity of the DM passband. To verify the above design concept, an X-band prototype operating at 8 GHz has been fabricated and measured. A good agreement is observed between the simulations and the measurements.


2017 ◽  
Vol 7 (5) ◽  
pp. 1918-1921
Author(s):  
H. Alsaif

In this paper, a novel highly compact microstrip monopole antenna with adjusted ground plane for ultra-wideband (UWB) applications is proposed. The patch antenna is composed of a trimmed radiator and rectangular ground plane with four slots providing relatively extreme wide operating frequency from 2.8 till 16.2 GHz based on -10 dB criteria. The high matching impedance in the design results in ultra-wide bandwidth that covers the entire BW allocated by FCC for UWB applications. At the same time, the presented antenna is distinguished by significantly miniaturized structure with total size of 13 mm x 10 mm printed on a substrate material of Rogers Duriod RT 5880 LZ with relative permittivity of εr=1.9 and loss tangent δ of 0.0009. The suggested antenna is appropriate for miniature wireless gadgets. The patch has been investigated, and optimized in terms of operating frequency, impedance matching, radiation characteristics, structure size, and fabrication cost.


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