Design of an Economical Compact Coaxial Cavity Combline Filter for 3G TD Base Station

2014 ◽  
Vol 704 ◽  
pp. 219-224
Author(s):  
Guang Ming Zheng
Keyword(s):  
Return Loss ◽  
Base Station ◽  
Center Frequency ◽  
Coaxial Cavity ◽  
Transmission Zeros ◽  
Rejection Filter ◽  
Relative Bandwidth ◽  
Theory Result ◽  
The Cross ◽  
High Rejection

The cross coupled microwave filter is widely used in the communication sub system .The synthesis of the cross coupled filter is from prescribed transmission zeros and return loss till the attainment of the coupling matrix of each cavity. A compact narrowband combline high rejection filter with cross coupled is presented. A configureiton using identical resonator post with capacitance-loading is introduced. Tested results show that with order-8 filter center frequency at 2017.5MHz, return loss lower than-25dB can be achieved over a relative bandwidth of 1.29%. A sample filter has been fabricated and tested result confirmed the theory result.

Design and Simulation of the Inverted F Antenna for RFID Tags

2013 ◽  
Vol 303-306 ◽  
pp. 1822-1825
Author(s):  
Bin Wang ◽  
Shu Hui Yang ◽  
Di Feng ◽  
Ting Lan Wang ◽  
Zhen Wei Su ◽  
...  
Keyword(s):  
Frequency Band ◽  
Return Loss ◽  
Center Frequency ◽  
Rfid Tags ◽  
Physical Size ◽  
Rfid System ◽  
Relative Bandwidth ◽  
Container Management

In this paper, an inverted F antenna works in the 5.8GHz frequency band is proposed. On the platform of Ansoft HFSS14 , the antenna’s return loss reaches -51.97dB at the center frequency 5.8GHz and the relative bandwidth is about 22.4％ when the return loss is less than -10dB. Also ,the size of the antenna is only 18mm*15mm. Compared with the existing antenna works in the same frequency band , the inverted F antenna proposed has a lower return loss and smaller physical size. The new designed antenna can be applied to the RFID system of road tolls and container management, which have certain values for application.

Wide-stopband bandpass-filtering power divider with high-frequency selectivity

2017 ◽  
Vol 9 (10) ◽  
pp. 1931-1936 ◽  
Author(s):  
Kaijun Song ◽  
Yifang Zhou ◽  
Maoyu Fan ◽  
Yu Zhu ◽  
Yong Fan
Keyword(s):  
Insertion Loss ◽  
High Frequency ◽  
Return Loss ◽  
Signal Transmission ◽  
Frequency Selectivity ◽  
Power Divider ◽  
Center Frequency ◽  
Frequency Range ◽  
Transmission Zeros ◽  
Stopband Attenuation

A wide-stopband bandpass-filtering power divider with high-frequency selectivity has been proposed in this paper. The input and output feeding lines and eight 1/4 wavelength resonators are used to realize the signal transmission. In order to obtain good frequency selectivity, source-load coupling transmission path is used to generate transmission zeros near the passband. A four-way power divider with bandpass-filtering response and high-frequency selectivity is designed, fabricated, and measured. The measured results agree with the simulated ones closely in the desirable frequency range. The measured center frequency of the power divider is 2.38 GHz with input return loss of 31.2 dB, while the measured insertion loss is about 1 dB (not including ideal 6 dB four-way power dividing insertion loss). Moreover, the measured 3-dB bandwidth is 12% and the measured stopband attenuation is >15 dB from 2.59 to 7.7 GHz. In addition, two transmission zeros of 1.9 and 2.8 GHz are located near the passband. The measured output isolations are all >15.7 dB.

A Novel Dual-Mode Microstrip Bandpass Filter with a Pair of Equal Crossed Slots

2012 ◽  
Vol 236-237 ◽  
pp. 1383-1388
Author(s):  
Su Ping Li ◽  
Cheng Guo Chang ◽  
Wei Wu
Keyword(s):  
Insertion Loss ◽  
Bandpass Filter ◽  
Center Frequency ◽  
Low Loss ◽  
Dual Mode ◽  
Transmission Zeros ◽  
Filter Structure ◽  
Relative Bandwidth

A novel dua1-mode microstrip bandpass filter with two triangle corner cuts and a pair of equal crossed slots is proposed. The performance of the designed filter is studied in detail. The proposed filter structure uses a single patch without coupling gaps. The center frequency is about 2.11GHz. The 3dB relative bandwidth is 9.95%, and the minimum insertion loss in the passband is 0.12dB. Two transmission zeros can be implemented on both sides of the passband. The insertion loss is l0dB within 2.04-2.18GHz. The effect on the filter’s performance by changing filter parameters is studied. The results show that this new filter can provide a low loss and make miniaturization easy.

Design of Novel Compact Quad-Band Bandpass Filter with High Selectivity

Frequenz ◽  
2020 ◽  
Vol 74 (1-2) ◽  
pp. 53-59
Author(s):  
Qingchun Cao ◽  
Hui Liu ◽  
Li Gao
Keyword(s):  
Return Loss ◽  
High Selectivity ◽  
Bandpass Filter ◽  
Center Frequency ◽  
Transmission Zeros ◽  
Compact Size ◽  
Left And Right ◽  
Embedded Structure ◽  
Better Than ◽  
Good Agreement

AbstractThis paper presents a compact quad-band bandpass filter. The filter is realized by multi-embedded stub-load resonators. By utilizing multi-embedded structure, the whole filter exhibits a compact size. And due to the multi-section stub-loaded lines, four passbands can be realized and the center frequency of the four passbands can be controlled individually to accommodate different communication protocols. Moreover, by using 0° degree feed structure, there are two transmission zeros locates at left and right side of a passband, which greatly enhance the selectivity. To validate the proposed idea, a quad-band bandpass filter, which operates at 2/2.7/3.45/4.55 GHz is implemented. The insertion loss is smaller than 2 dB and return loss is better than 10 dB. Good agreement between the predicted and measured results demonstrates the proposed idea.

scholarly journals A Bandpass Filter Using Half Mode SIW Structure with Step Impedance Resonator

Electronics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 51
Author(s):  
Min-Hang Weng ◽  
Chin-Yi Tsai ◽  
De-Li Chen ◽  
Yi-Chun Chung ◽  
Ru-Yuan Yang
Keyword(s):  
Insertion Loss ◽  
Return Loss ◽  
Bandpass Filter ◽  
Filter Design ◽  
Design Concept ◽  
Center Frequency ◽  
Substrate Integrated Waveguide ◽  
Design Curve ◽  
Transmission Zeros ◽  
Measured Response

This paper presents a miniaturized bandpass filter, which uses half mode substrate integrated waveguide (HMSIW) structure with embedded step impedance structure (SIS). By embedding the stepped impedance structure into the top metal of the waveguide cavity, the center frequency can be quickly shifted to a lower frequency. The operating center frequency of the proposed bandpass filter (BPF) using HMSIW resonators with embedded SIS is tunable as functions of the parameters of the SIS. The design curve is provided. A filter example of the center frequency of the filter at 3.5 GHz is fabricated and measured, having the insertion loss |S21| less than 3 dB, and the return loss |S11| greater than 10 dB. The transmission zeros are located at 2.95 GHz and 3.95 GHz on both sides of the passband, both of which are lower than 30 dB. The simulation result and the measured response conform to the proposed design concept. The proposed HMSIW filter design is in line with the current 5G communication trend.

scholarly journals High Gain Circularly Polarized Pentagonal Microstrip for Massive MIMO Base Station

2019 ◽  
Vol 8 (3) ◽  
pp. 83-91
Author(s):  
R. S. Bhadade ◽  
S. P. Mahajan
Keyword(s):  
Massive Mimo ◽  
Return Loss ◽  
Multiple Input Multiple Output ◽  
Axial Ratio ◽  
High Gain ◽  
Base Station ◽  
Cellular Systems ◽  
Center Frequency ◽  
Impedance Bandwidth ◽  
Circularly Polarized

In this paper we propose a circularly polarized pentagonal microstrip antenna on a suspended substrate with coaxial probe feed and five loaded slits for Massive MIMO BS Antenna applications. Massive Multiple-Input Multiple-Output (MIMO) is one of the key component to be incorporated in the 5G cellular systems. The proposed antenna is successfully simulated using HFSS 13.0, fabricated on a FR-4 substrate and measured. The proposed antenna exhibits a much higher gain of 6.17dB, improved impedance bandwidth of 171.9 MHz (Return loss, S11= -10dB) , axial ratio bandwidth (< 3dB) of 135 MHz , patch area of 1775 mm2  , and also yields return loss better than -15 dB around the center frequency of 2.45 GHz (ISM Band). Measured characteristics of the antenna are in good agreement with the simulated results.

Compact microstrip bandpass filter using dual closed-loop stepped impedance resonator

2018 ◽  
Vol 10 (4) ◽  
pp. 405-411 ◽  
Author(s):  
Salif N. Dembele ◽  
Ting Zhang ◽  
Jingfu Bao ◽  
Denis Bukuru
Keyword(s):  
Circuit Design ◽  
Return Loss ◽  
Closed Loop ◽  
Bandpass Filter ◽  
Center Frequency ◽  
Fractional Bandwidth ◽  
Transmission Zeros ◽  
Measurement Results ◽  
Frequency Position ◽  
Stepped Impedance Resonator

AbstractA dual closed-loop stepped impedance resonator (DCLSIR) is investigated and used in designing a compact microstrip bandpass filter (BPF). The proposed DCLSIR is symmetrical; as a result, the symmetric characteristics of the resonator have been used. The design equations are derived and used to support the circuit design. The center frequency, position of transmission zeros, and fractional bandwidth (FBW) are easily tuned by changing the physical dimensions of the resonator. Three transmission zeros are generated to improve the performance in the upper stopband. A DCLSIR prototype BPF is fabricated with a center frequency of 9.3 GHz, and evaluated to validate the design concept. The measured FBW is 9.25%, the insertion loss is 1.58 dB, and the return loss is over 17 dB. The measurement results agree well with the simulation results.

Miniaturized dual-band filter with return loss bandwidth and transmission zero control

2017 ◽  
Vol 9 (7) ◽  
pp. 1459-1465
Author(s):  
Di Lu ◽  
N. Scott Barker ◽  
Xiao-Hong Tang
Keyword(s):  
Return Loss ◽  
Filter Design ◽  
Frequency Control ◽  
Magnetic Coupling ◽  
Dual Band ◽  
Center Frequency ◽  
Transmission Zeros ◽  
Simple Strategy ◽  
Compact Size ◽  
High Flexibility

In this paper, a compact dual-band bandpass filter (DB-BPF) using new dual-mode resonator-loaded resonators (DM-RLRs) is presented and investigated to simultaneously achieve controllable return loss (RL), bandwidth (BW) and transmission zeros (TZs), and the simple strategy for this type of filter design is proposed. The DB-BPF consists of two high-flexibility DM-RLRs with separated electric and magnetic coupling (SEMC). Specifically, the proposed DM-RLR provides the DB-BPF with center frequency control as well as RL control, and SEMC is utilized for the BW and TZ control. To facilitate the design, a simple optimization-based design strategy is proposed and employed, resulting in an example layout. Finally, the example filter, with center frequencies of 1.57 GHz (channel 1 for GPS) and 3.5 GHz (channel 2 for WiMAX), is fabricated and measured. The measurement insertion loss and RL are 0.9/0.9 and 17/20 dB. The fabricated DB-BPF also exhibits a compact size of 0.12λg × 0.08λg at 1.57 GHz.

Tunable balanced to balanced filtering power divider with high common-mode suppression

Frequenz ◽  
2020 ◽  
Vol 74 (7-8) ◽  
pp. 263-270
Author(s):  
Cao Zeng ◽  
Xue Han Hu ◽  
Feng Wei ◽  
Xiao Wei Shi
Keyword(s):  
Return Loss ◽  
High Selectivity ◽  
Power Divider ◽  
Center Frequency ◽  
Differential Mode ◽  
Common Mode ◽  
Mode Suppression ◽  
The Common ◽  
Equal Power ◽  
Good Agreement

AbstractIn this paper, a tunable balanced-to-balanced in-phase filtering power divider (FPD) is designed, which can realize a two-way equal power division with high selectivity and isolation. A differential-mode (DM) passband with a steep filtering performance is realized by applying microstrip stub-loaded resonators (SLRs). Meanwhile, six varactors are loaded to the SLRs to achieve the center frequency (CF) and bandwidth adjustment, respectively. U-type microstrip lines integrated with stepped impedance slotline resonators are utilized as the differential feedlines, which suppress the common-mode (CM) intrinsically, making the DM responses independent of the CM ones. A tuning center frequency from 3.2 to 3.75 GHz and a fractional bandwidth (12.1–17.6%) with more than 10 dB return loss and less than 2.3 dB insertion loss can be achieved by changing the voltage across the varactors. A good agreement between the simulated and measured results is observed. To the best of authors' knowledge, the proposed balanced-to-balanced tunable FPD is first ever reported.

scholarly journals Novel Hexagonal Dual-Mode Substrate Integrated Waveguide Filter with Source-Load Coupling

2014 ◽  
Vol 2014 ◽  
pp. 1-5
Author(s):  
Ziqiang Xu ◽  
Gen Zhang ◽  
Hong Xia ◽  
Meijuan Xu
Keyword(s):  
Center Frequency ◽  
Substrate Integrated Waveguide ◽  
Fractional Bandwidth ◽  
Dual Mode ◽  
Transmission Zeros ◽  
Cavity Structure ◽  
Waveguide Filter ◽  
And Performance ◽  
Single Cavity ◽  
Good Agreement

Hexagonal dual-mode cavity and its application to substrate integrated waveguide (SIW) filter are presented. The hexagonal SIW resonator which can combine flexibility of rectangular cavity and performance of circular cavity is convenient for dual-mode bandpass filters design. By introducing coupling between source and load, the filter not only has good selectivity due to two controllable transmission zeros, but also has a small size by the virtue of its single-cavity structure. A demonstration filter with a center frequency of 10 GHz and a 3 dB fractional bandwidth of 4% is designed and fabricated to validate the proposed structure. Measured results are in good agreement with simulated ones.

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