A Wide Stopband Balun Bandpass Filter with Its Application to Balanced Quasi-Yagi Antenna

A new microstrip balun bandpass filter (BPF) with wide stopband is presented. It is realized by utilizing the out-of-phase feature of standing-wave distribution on a half-wavelength (λ/2) open-ended microstrip line and the resonant characteristics of the triple-mode resonators. For demonstration, a prototype balun BPF operating at central frequency (f0) of 2.34 GHz with fractional bandwidth (FBW) of about 16.7% is designed. The presented balun BPF not only exhibits nice balanced response with 0.47 dB magnitude imbalance and 4.3° phase difference but also achieves 30-dB harmonic suppression up to 6.40 GHz (2.7f0). Afterward, this presented design is embedded into a balanced quasi-Yagi antenna to obtain high-selective radiation and wide stopband rejection. Experimental results of the implemented antenna indicate less than −10 dB reflection coefficient, 4.49–5.38 dBi gain, and 12.71–19.62 dB front-to-back ratio within the operating bandwidth.

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A Wideband Bandpass Filter Integrated Single-Pole Double-Throw Switch with Wide Stopband

Frequenz ◽

10.1515/freq-2018-0045 ◽

2018 ◽

Vol 72 (11-12) ◽

pp. 533-537 ◽

Cited By ~ 1

Author(s):

Jin Xu ◽

Qi-Hang Cai ◽

Zhi-Yu Chen

Keyword(s):

Insertion Loss ◽

Bandpass Filter ◽

Fractional Bandwidth ◽

Central Frequency ◽

Resonant Frequencies ◽

Capacitively Coupled ◽

Filter Theory ◽

Compact Size ◽

Better Than ◽

Coupled Resonator

Abstract This paper proposes a wideband bandpass filter (BPF) integrated single-pole double-throw (SPDT) switch by using the capacitively coupled LC resonators with loaded p-i-n diodes. The BPF-integrated on-state channel can be synthesized by using the coupled resonator filter theory, and the off-state channel with high suppression is built due to the misaligned resonant frequencies of LC resonators. As an example, a BPF-integrated SPDT switch is designed and fabricated with the central frequency of 1 GHz and the 3 dB fractional bandwidth of 29.7 %. The on-state channel has a measured insertion loss of 1.23 dB, and a 20 dB rejection wide stopband from 1.47 GHz to 8.6 GHz. The off state channel has a 43 dB suppression around 1 GHz. The isolation between two ports is better than 52.4 dB. The fabricated BPF-integrated SPDT switch size including bias circuits but excluding feeding lines has a compact size of 0.086 λg×0.096 λg.

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Coplanar Stripline-Fed Wideband Yagi Dipole Antenna with Filtering-Radiating Performance

Electronics ◽

10.3390/electronics9081258 ◽

2020 ◽

Vol 9 (8) ◽

pp. 1258

Author(s):

Yong Chen ◽

Gege Lu ◽

Shiyan Wang ◽

Jianpeng Wang

Keyword(s):

High Frequency ◽

Dipole Antenna ◽

Frequency Selectivity ◽

Antenna Design ◽

Initial Structure ◽

Coplanar Stripline ◽

Half Wavelength ◽

Yagi Antenna ◽

Operating Bandwidth ◽

Good Agreement

In this article, a wideband filtering-radiating Yagi dipole antenna with the coplanar stripline (CPS) excitation form is investigated, designed, and fabricated. By introducing an open-circuited half-wavelength resonator between the CPS structure and dipole, the gain selectivity has been improved and the operating bandwidth is simultaneously enhanced. Then, the intrinsic filtering-radiating performance of Yagi antenna is studied. By implementing a reflector on initial structure, it is observed that two radiation nulls appear at both lower and upper gain passband edges, respectively. Moreover, in order to improve the selectivity in the upper stopband, a pair of U-shaped resonators are employed and coupled to CPS directly. As such, the antenna design is finally completed with expected characteristics. To verify the feasibility of the proposed scheme, a filtering Yagi antenna prototype with a wide bandwidth covering from 3.64 GHz to 4.38 GHz is designed, fabricated, and measured. Both simulated and measured results are found to be in good agreement, thus demonstrating that the presented antenna has the performances of high frequency selectivity and stable in-band gain.

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Miniaturized bandpass filter based on double spiral stripline resonators

Ural Radio Engineering Journal ◽

10.15826/urej.2021.5.1.002 ◽

2021 ◽

Vol 5 (1) ◽

pp. 21-31

Author(s):

B. A. Belyaev ◽

◽

A. M. Serzhantov ◽

An. A. Leksikov ◽

Ya. F. Bal’va ◽

...

Keyword(s):

Multilayer Structure ◽

Bandpass Filter ◽

Center Frequency ◽

Fractional Bandwidth ◽

Central Frequency ◽

Dielectric Substrates ◽

Dielectric Layers ◽

Spiral Inductors ◽

Double Spiral ◽

Left And Right

A new miniature monolithic bandpass filter, which can be manufactured using multilayer standard all-PCB technology, is presented. Each resonator in the filter is formed by metal spirals of the left and right wist inserted into each other, in which one pair of adjacent ends is grounded, and the other is free. Spiral inductors have the form of identical rectangular frames and are designed on dielectric substrates, located on a multilayer structure strictly under each other with alternating turns of the left and right spirals. The design of the filter based on such multilayer double-spiral resonators is both small in size, and highly selective, which is proved by the measured characteristics of the fourth order filter fabricated at seven dielectric layers of RO4350B material. The filter has the central frequency of the passband f0 = 60 MHz, and the fractional bandwidth Δf / f0 = 18%, while the size of the device is of the device are only 34 × 16.5 × 4.3 mm3 (0.007λ0 × 0.003λ0 × 0.001λ0, where λ0 is the wavelength at the center frequency f0). The filter has a wide stopband, which extends up to the frequency of 16f0 at a level of –38 dB.

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Coupled microstrip line bandpass filter with harmonic suppression using right-angle triangle grooves

Microwave and Optical Technology Letters ◽

10.1002/mop.24644 ◽

2009 ◽

Vol 51 (10) ◽

pp. 2313-2318 ◽

Cited By ~ 6

Author(s):

Ashraf S. Mohra

Keyword(s):

Microstrip Line ◽

Bandpass Filter ◽

Harmonic Suppression

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A Quasi-Elliptic Bandpass Filter-Integrated Single-Pole Double-Throw Switch

Frequenz ◽

10.1515/freq-2016-0114 ◽

2017 ◽

Vol 71 (5-6) ◽

Cited By ~ 2

Author(s):

Yu-Xue Ji ◽

Jin Xu ◽

Zhao-Zhao Li ◽

Huan Wang ◽

Jin-Jie Huang

Keyword(s):

Insertion Loss ◽

Bandpass Filter ◽

Impedance Matching ◽

Bandpass Filters ◽

Design Approach ◽

Fractional Bandwidth ◽

Central Frequency ◽

Low Insertion Loss ◽

Parallel Configuration

AbstractThis paper proposes a quasi-elliptic bandpass filter-integrated single-pole double-throw (SPDT) switch. The series-parallel configuration of p-i-n diodes embedded into the impedance matching circuit is proposed to combine two quasi-elliptic response bandpass filters to constitute the proposed SPDT switch. To validate our design approach, a proposed quasi-elliptic bandpass filter-integrated SPDT switch is designed and fabricated with a central frequency of 1.25 GHz and a 3 dB fractional bandwidth of 16 %. Low insertion loss in the on state and good isolation in the off state are achieved. The switch size including bias circuits but excluding feeding lines is 0.447λ

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