scholarly journals High Selectivity Slot-Coupled Bandpass Filter Using Discriminating Coupling and Source-Load Coupling

2020 ◽  
Vol 10 (19) ◽  
pp. 6807
Author(s):  
Jie Cui ◽  
Haojie Chang ◽  
Renli Zhang
Keyword(s):  
High Selectivity ◽  
Bandpass Filter ◽  
Second Harmonic ◽  
Center Frequency ◽  
Coupled Line ◽  
Half Wavelength ◽  
Quarter Wavelength ◽  
Coupling Path ◽  
Signal Cancellation ◽  
Line Path

A multilayer bandpass filter with high selectivity is proposed in this letter. Discriminating coupling formed by slot-coupled quarter-wavelength and half-wavelength resonators introduces a zero at 3f0 (f0 is the center frequency) and the second harmonic is also suppressed due to the quarter-wavelength resonators. Owing to multilayer structure, source-load coupling is introduced to improve selectivity. Then an extra coupled line path is added with the same amplitude as the discriminating coupling path while they are out of phase. Thus signal cancellation produces three extra transmission zeros, with the selectivity and suppression performance further improved. To validate the design, a prototype bandpass filter centered at 2.49 GHz with 3 dB fractional bandwidth of 8.1% is fabricated. Both simulated and measured results are in good agreement and show good performance of the proposed bandpass filter.

scholarly journals A Dual-Mode Bandpass Filter with Multiple Controllable Transmission-Zeros Using T-Shaped Stub-Loaded Resonators

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Zh. Yao ◽  
C. Wang ◽  
N. Y. Kim
Keyword(s):  
High Selectivity ◽  
Bandpass Filter ◽  
Second Harmonic ◽  
Center Frequency ◽  
Harmonic Frequency ◽  
Dual Mode ◽  
Mode Theory ◽  
Transmission Zeros ◽  
Coupling Capacitance ◽  
Compact Size

A dual-mode broadband bandpass filter (BPF) with multiple controllable transmission-zeros using T-shaped stub-loaded resonators (TSSLRs) is presented. Due to the symmetrical plane, the odd-even-mode theory can be adopted to characterize the BPF. The proposed filter consists of a dual-mode TSSLR and two modified feed-lines, which introduce two capacitive and inductive source-load (S-L) couplings. Five controllable transmission zeros (TZs) can be achieved for the high selectivity and the wide stopband because of the tunable amount of coupling capacitance and inductance. The center frequency of the proposed BPF is 5.8 GHz, with a 3 dB fraction bandwidth of 8.9%. The measured insertion and return losses are 1.75 and 28.18 dB, respectively. A compact size and second harmonic frequency suppression can be obtained by the proposed BPF with S-L couplings.

scholarly journals Inter-connected coupled lines Resonator topology for bandpass filter application

2020 ◽  
Vol 10 (3) ◽  
pp. 2523
Author(s):  
Mohd Nasiruddin Hushim ◽  
Norfishah Ab Wahab ◽  
Tn. Syarifah Atifah Tn. Mat Zin ◽  
Norlia Ghazali
Keyword(s):  
Bandpass Filter ◽  
Higher Order ◽  
Coupled Line ◽  
Microstrip Technology ◽  
Half Wavelength ◽  
Quarter Wavelength ◽  
Coupled Lines ◽  
In Series ◽  
Tan Δ ◽  
Filter Response

This paper presents an inter-connected side-shorted coupled-line resonator topology as a base cell. The base cell is built from two single-shorted quarter-wavelength coupled-line sections, connected in series to give a half-wavelength coupled-line that creates a single resonance of bandpass filter response. Higher-order bandpass filter is produced by adding new single-shorted coupled-line sections, cascaded in an inter-connected manner to the base cell. This new topology creates a unique arrangement that caused cross coupling effects between the resonators, resulting to the occurrence of transmission zeros that lead to the improvement of selectivity of the higher order bandpass filter response. For validation of concept, 2<sup>nd</sup> and 3<sup>rd</sup> order bandpass filters were fabricated using microstrip technology on Roger 3210 substrate with parameter of <em>Ɛr</em> = 10.2, <em>h</em> = 1.27 mm and <em>tan δ</em> = 3x10-3. The filters were measured and the results show good agreement with simulation results.

Parallel-coupled stub-loaded resonator bandpass filter with ultra-wideband passband on multilayer liquid crystal polymer substrates

2015 ◽  
Vol 8 (8) ◽  
pp. 1183-1186 ◽  
Author(s):  
S. Almorqi ◽  
H. Shaman ◽  
A. Alamoudi
Keyword(s):  
Liquid Crystal ◽  
Bandpass Filter ◽  
Liquid Crystal Polymer ◽  
Ultra Wideband ◽  
Center Frequency ◽  
Coupled Line ◽  
Crystal Polymer ◽  
Quarter Wavelength ◽  
Coupled Lines ◽  
Chebyshev Filter

A multilayer bandpass filter with ultra-wideband passband is presented in this paper. The filter is designed to have a very wide passband with a fractional bandwidth of about 180% at a center frequency of 10.5 GHz. The filter consists of two sections of parallel-coupled lines loaded at the center with short-circuited stub. Each of the coupled line sections and short-circuited stubs is designed to be a quarter-wavelength long at the desired center frequency. As a result, the filter exhibited a selective filtering characteristic equivalent to a five-pole Chebyshev filter with a very low insertion loss. The proposed filter is realized and fabricated using multilayer liquid crystal polymer substrate. The design is successfully realized in theory and verified by full-wave electromagnetic simulation of the full layout and the experiment where excellent agreement is obtained.

scholarly journals Effect of the defected microstrip structure shapes on the performance of dual-band bandpass filter for wireless communications

2021 ◽  
Vol 10 (1) ◽  
pp. 232-240
Author(s):  
Mussa Mabrok ◽  
Zahriladha Zakaria ◽  
Yully Erwanti Masrukin ◽  
Tole Sutikno ◽  
Hussein Alsariera
Keyword(s):  
Wireless Communication ◽  
Communication Systems ◽  
Bandpass Filter ◽  
Dual Band ◽  
Center Frequency ◽  
Wireless Communication Systems ◽  
Notch Band ◽  
Quarter Wavelength ◽  
Crucial Component ◽  
Microstrip Structure

Due to the progression growth of multiservice wireless communication systems in a single device, multiband bandpass filter has attract a great attention to the end user. Therefore, multiband bandpass filter is a crucial component in the multiband transceivers systems which can support multiple services in one device. This paper presents a design of dual-band bandpass filter at 2.4 GHz and 3.5 GHz for WLAN and WiMAX applications. Firstly, the wideband bandpass filter is designed at a center frequency of 3 GHz based on quarter-wavelength short circuited stub. Three types of defected microstrip structure (DMS) are implemented to produce a wide notch band, which are T-inversed shape, C-shape, and U- Shape. Based on the performance comparisons, U-shaped DMS is selected to be integrated with the bandpass filter. The designed filter achieved two passbands centered at 2.51 GHz and 3.59 GHz with 3 dB bandwidth of 15.94 % and 15.86 %. The proposed design is very useful for wireless communication systems and its applications such as WLAN and WiMAX 

Miniaturized Wideband Bandpass Filter based on Capacitor-loaded One-eighth Wavelength Coupled Line

2021 ◽  
Vol 36 (7) ◽  
pp. 865-871
Author(s):  
Jin Shi ◽  
Jiancheng Dong ◽  
Kai Xu ◽  
Lingyan Zhang
Keyword(s):  
Insertion Loss ◽  
Simple Structure ◽  
Bandpass Filter ◽  
State Of The Art ◽  
Center Frequency ◽  
Fractional Bandwidth ◽  
Coupled Line ◽  
Transmission Zeros ◽  
Compact Size ◽  
Multiple Transmission

A novel miniaturized wideband bandpass filter (BPF) using capacitor-loaded microstrip coupled line is proposed. The capacitors are loaded in parallel and series to the coupled line, which makes the filter just require one one-eighth wavelength coupled line and achieve filtering response with multiple transmission poles (TPs) and transmission zeros (TZs). Compared with the state-of-the-art microstrip wideband BPFs, the proposed filter has the advantages of compact size and simple structure. A prototype centered at 1.47 GHz with the 3-dB fractional bandwidth of 86.5% is demonstrated, which exhibits the compact size of 0.003λ2 g (λg is the guided wavelength at the center frequency) and the minimum insertion loss of 0.37 dB.

scholarly journals A New Ultracompact Narrow Bandpass Microstrip Filter Using Double-Negative Quasiplanar Cells

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Mohammad Reza Khawary ◽  
Vahid Nayyeri ◽  
Seyed Mohammad Hashemi ◽  
Mohammad Soleimani
Keyword(s):  
Printed Circuit Board ◽  
High Selectivity ◽  
Bandpass Filter ◽  
Circuit Board ◽  
Center Frequency ◽  
Double Negative ◽  
Fractional Bandwidth ◽  
Printed Circuit ◽  
Full Wave ◽  
Good Agreement

This paper presents a novel ultracompact narrow bandpass filter with high selectivity. The proposed filter is composed of cascading two basic cells. Each cell is basically a microstrip line loaded with a quasiplanar resonator and series gaps which can be fabricated using a standard multilayer printed circuit board technology. The structure is analyzed through an equivalent circuit and full-wave simulations. The simulation results are compared with experimental measurements demonstrating a good agreement between them. The measurement indicates that the realized bandpass filter at the center frequency of 1 GHz has a fractional bandwidth of 2.2%. Most importantly, in comparison with other similar recent works, it is shown that the proposed filter has the smallest size.

High selectivity quarter‐wavelength resonator bandpass filter utilizing source‐load coupling

2019 ◽  
Vol 62 (3) ◽  
pp. 1176-1182 ◽  
Author(s):  
Muhammad Sufian Anwar ◽  
Qunsheng Cao ◽  
Syed Ashhad Burney
Keyword(s):  
High Selectivity ◽  
Bandpass Filter ◽  
Quarter Wavelength
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