scholarly journals Frequency-Tunable and Pattern Diversity Antennas for Cognitive Radio Applications

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
A. H. Ramadan ◽  
J. Costantine ◽  
Y. Tawk ◽  
C. G. Christodoulou ◽  
K. Y. Kabalan
Keyword(s):  
Cognitive Radio ◽  
Bandpass Filter ◽  
Microstrip Antennas ◽  
Open Loop ◽  
Tunable Filter ◽  
Radiation Characteristics ◽  
Wideband Antenna ◽  
Pattern Diversity ◽  
Frequency Tunable ◽  
Good Agreement

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.

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
Keyword(s):  
Bandpass Filter ◽  
Ring Resonator ◽  
Cognitive Radios ◽  
Ultra Wideband ◽  
Planar Antenna ◽  
Radiation Characteristics ◽  
Total Size ◽  
Frequency Agile ◽  
Narrow Bands ◽  
Good Agreement

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.

scholarly journals Substrate integrated waveguide bandpass filter for short range device application using rectangular open loop resonator

2021 ◽  
Vol 11 (5) ◽  
pp. 3747
Author(s):  
Dian Widi Astuti ◽  
Rizki Ramadhan Putra ◽  
Muslim Muslim ◽  
Mudrik Alaydrus
Keyword(s):  
Short Range ◽  
Return Loss ◽  
Bandpass Filter ◽  
Open Loop ◽  
Frequency Region ◽  
Substrate Integrated Waveguide ◽  
Network Analyzer ◽  
Measurement Results ◽  
Simulation Results ◽  
Good Agreement

The substrate integrated waveguide (SIW) structure is the candidate for many application in microwave, terahertz and millimeter wave application. It because of SIW structure can integrate with any component in one substrate than others structure. A kind components using SIW structure is a filter component, especialy bandpass filter. This research recommended SIW bandpass filter using rectangular open loop resonator for giving more selectivity of filter. It can be implemented for short range device (SRD) application in frequency region 2.4 - 2.483 GHz. Two types of SIW bandpass filter are proposed. First, SIW bandpass filter is proposed using six rectangular open loop resonators while the second SIW bandpass filter used eight rectangular open loop resonators. The simulation results for two kinds of the recommended rectangular open loop resonators have insertion loss (S<sub>21</sub> parameter) below 2 dB and return loss (S<sub>11</sub> parameter) more than 10 dB. Fabrication of the recommended two kind filters was validated by Vector Network Analyzer. The measurement results for six rectangular open loop resonators have 1.32 dB for S<sub>21</sub> parameter at 2.29 GHz while the S<sub>11</sub> parameter more than 18 dB at 2.26 GHz – 2.32 GHz. While the measurement results has good agreement for eight rectangular open loop resonators. Its have S<sub>21</sub> below 2.2 dB at 2.41 – 2.47 GHz and S<sub>11</sub> 16.27 dB at 2.38 GHz and 11.5 dB at 2.47 GHz.

Electronically Reconfigurable Varactor-Loaded HMSIW Bandpass Filter

Frequenz ◽  
2018 ◽  
Vol 72 (5-6) ◽  
pp. 227-230
Author(s):  
Jing-Pan Song ◽  
Xin-Yi Wang ◽  
Feng Wei ◽  
Xiao-Wei Shi
Keyword(s):  
Reverse Bias ◽  
Tuning Range ◽  
Bandpass Filter ◽  
Tunable Filter ◽  
Ring Resonators ◽  
Reverse Bias Voltage ◽  
Split Ring ◽  
Split Ring Resonators ◽  
Filter Size ◽  
Good Agreement

AbstractA varactor-loaded half-mode substrate integrated waveguide (HMSIW) reconfigurable bandpass filter (BPF) is proposed in this paper. The proposed BPF is composed of complementary split-ring resonators (CSRRs) and varactors. Meanwhile, a nonmetalized via is employed in the center of the CSRR. It is noted that the varactor is embedded into the nonmetalized via, which can significantly reduce the tunable filter size. By changing the reverse bias voltage of the varactor, the resonant frequency of the proposed filter can be adjusted. Moreover, low insert loss (IL) and wide tuning range can be achieved. In order to validate its practicability, a BPF with the frequency ranging from 1.9 GHz to 2.5 GHz is fabricated and good agreement between the simulated and measured results is observed.

scholarly journals Frequency Tunable Non-Reciprocal Bandpass Filter and Diplexer Using Time-Modulated Microstrip λg/2 Resonators

2020 ◽  
Author(s):  
Xiaohu Wu ◽  
Mahmoud Nafe ◽  
Alejandro Alvarez Melcon ◽  
Juan Sebastian Gomez-Diaz ◽  
Xiaoguang Liu
Keyword(s):  
Insertion Loss ◽  
Bandpass Filter ◽  
Frequency Tuning ◽  
Wide Frequency Range ◽  
Voltage Source ◽  
Resonator Structure ◽  
Frequency Tunable ◽  
Rf Signal ◽  
Modulation Voltage ◽  
Good Agreement

This paper presents novel designs of frequency reconfigurable distributed non-reciprocal bandpass filter and diplexer based on spatio-temporally modulated microstrip λg/2 resonators. The modulation is achieved by loading both ends of the λg/2 transmission line resonators with time-modulated capacitors. To provide an inherent biasing isolation between the RF and the modulation signals, the modulation voltage source is connected at the center of the resonator, where there is a natural voltage null. A single inductor is used to further enhance such biasing isolation. The wideband nature of this isolation scheme enables the tuning of the devices over a wide frequency range. With more than 30-dB RF to modulation isolation, the proposed resonator structure also enables low insertion loss by eliminating RF signal leakage to the modulation ports. Two examples of a 3-pole bandpass filter and a diplexer are demonstrated with good agreement between the measurement and the simulation. The fabricated filter shows a minimal insertion loss of 3.9 dB, a 20-dB isolation bandwidth of 42 MHz at 1.0 GHz, and frequency tuning range of 885-1031 MHz. The measured diplexer has two non-reciprocal bandpass channels at 829 MHz and 997 MHz, respectively. The two channels can be independently reconfigured without affecting each other.

scholarly journals Tuning the Resonance Frequency and Miniaturization of a Novel Microstrip Bandpass Filter

2018 ◽  
Vol 15 (2) ◽  
pp. 24
Author(s):  
Abbas Rezaei ◽  
Leila Noori
Keyword(s):  
Resonance Frequency ◽  
Design Process ◽  
Insertion Loss ◽  
Return Loss ◽  
Bandpass Filter ◽  
Design Method ◽  
Open Loop ◽  
Input Admittance ◽  
Low Insertion Loss ◽  
Good Agreement

In this paper, a compact microstrip bandpass filter is designed using two open loop resonators. In order to obtain a tunable bandpass response with low insertion loss, two stubs are loaded inside them. The design process is based on obtaining the input admittance. Then, using the input admittance, a method is presented to control the resonance frequency and miniaturization simultaneously. The obtained insertion loss and the return loss at the resonance frequency are 0.1 dB and 19.7 dB respectively. To verify the design method, the proposed filter is fabricated and measured. The measured results are in good agreement with the simulated results.

scholarly journals Multitransmission Zero Dual-Band Bandpass Filter Using Nonresonating Node for 5G Millimetre-Wave Application

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Liyun Shi ◽  
Jianjun Gao
Keyword(s):  
Bandpass Filter ◽  
Open Loop ◽  
Dual Band ◽  
Dual Mode ◽  
Millimetre Wave ◽  
Transmission Zeros ◽  
Coupling Path ◽  
Good Agreement

A planer millimetre-wave dual-band bandpass filter with multitransmission zeros is proposed for 5G application. This filter includes two dual-mode open-loop resonators. The U-shape nonresonating node is employed to generate an extra coupling path. Finally, a dual-band bandpass filter with five transmission zeros is obtained. The filter is fabricated and measured. Good agreement between simulation and measurement is obtained.

scholarly journals Frequency Tunable Non-Reciprocal Bandpass Filter and Diplexer Using Time-Modulated Microstrip λg/2 Resonators

2020 ◽  
Author(s):  
Xiaohu Wu ◽  
Mahmoud Nafe ◽  
Alejandro Alvarez Melcon ◽  
Juan Sebastian Gomez-Diaz ◽  
Xiaoguang Liu
Keyword(s):  
Insertion Loss ◽  
Bandpass Filter ◽  
Frequency Tuning ◽  
Wide Frequency Range ◽  
Voltage Source ◽  
Resonator Structure ◽  
Frequency Tunable ◽  
Rf Signal ◽  
Modulation Voltage ◽  
Good Agreement

This paper presents novel designs of frequency reconfigurable distributed non-reciprocal bandpass filter and diplexer based on spatio-temporally modulated microstrip λg/2 resonators. The modulation is achieved by loading both ends of the λg/2 transmission line resonators with time-modulated capacitors. To provide an inherent biasing isolation between the RF and the modulation signals, the modulation voltage source is connected at the center of the resonator, where there is a natural voltage null. A single inductor is used to further enhance such biasing isolation. The wideband nature of this isolation scheme enables the tuning of the devices over a wide frequency range. With more than 30-dB RF to modulation isolation, the proposed resonator structure also enables low insertion loss by eliminating RF signal leakage to the modulation ports. Two examples of a 3-pole bandpass filter and a diplexer are demonstrated with good agreement between the measurement and the simulation. The fabricated filter shows a minimal insertion loss of 3.9 dB, a 20-dB isolation bandwidth of 42 MHz at 1.0 GHz, and frequency tuning range of 885-1031 MHz. The measured diplexer has two non-reciprocal bandpass channels at 829 MHz and 997 MHz, respectively. The two channels can be independently reconfigured without affecting each other.

Design and Fabrication of a Novel Compact Bandpass Filter to Improve Spurious-Free Band

Frequenz ◽  
2017 ◽  
Vol 71 (3-4) ◽  
Author(s):  
Payman Rezaee ◽  
Michael Höft
Keyword(s):  
Quality Factor ◽  
Slow Wave ◽  
Bandpass Filter ◽  
Coupling Factor ◽  
Open Loop ◽  
External Quality ◽  
Full Wave ◽  
Measurement Results ◽  
Free Band ◽  
Good Agreement

AbstractIn this paper, a new microstrip slow wave open loop resonator is proposed. This resonator overcomes the substantial limitation of the conventional slow wave open loop resonators, which limits the spurious-free band of those resonators. The new proposed resonator improves the spurious-free band up to 8 times of the fundamental frequency, which is 3.16 times of the conventional slow wave open loop resonators. For the proposed resonator the coupling factor and the external quality factor curves, which are the design curves of a narrowband filter, are extracted using a full wave simulator, i. e. HFSS. These curves are utilized for the design of two three-pole Chebyshev bandpass filters. One of these filters is fabricated. Simulation and measurement results are reported which are in good agreement. Designed filters provide 75 % and 83 % of footprint reduction in comparison with the conventional open loop resonator filters. Different parameters which can improve the spurious-free band are explained in the paper.

A tunable open ring coupling structure and its application in fully tunable bandpass filter

2019 ◽  
Vol 11 (08) ◽  
pp. 782-786
Author(s):  
Zhonghai Zhang ◽  
Fei Zhao ◽  
Aiting Wu
Keyword(s):  
Bandpass Filter ◽  
Design Procedure ◽  
Tunable Filter ◽  
Operating Frequency ◽  
Coupling Structure ◽  
Open Ring ◽  
Tunable Coupling ◽  
Tunable Resonator ◽  
Good Agreement ◽  
Tunable Bandpass Filter

AbstractThis letter presents a novel tunable coupling structure to simplify the design complexity of the miniaturized fully tunable filter by using open ring and varactors. Based on the proposed novel tunable coupling structure, a fully tunable bandpass filter is implemented with independently tunable operating frequency and bandwidth. The tunable resonator and tunable coupling structure can be easily combined to improve Out-of-band suppression performance. The design procedure of a fully tunable bandpass filter consists of five tunable cavities and tunable coupling rings is also proposed. A prototype of the proposed fully tunable filter is built to verify the design experimentally. Good agreement between simulated and measured results is obtained.

Sign in / Sign up

Export Citation Format

Share Document