Browsing by Author "Chou, Po-Jung"

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A Novel Filter Bank Using Serial-Switched Structure
(2016-01-01)
Tsai, Hsiu-Min
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Chou, Po-Jung
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Chang, Chi-Yang
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交大名義發表
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National Chiao Tung University
A novel filter bank using serial-switched structure for the commercial bands of Band40, WIFI, and Band38 application is proposed. The proposed triple-band filter bank adopt the three order Chebyshev short-ended hairpin comb filters which embedded a pair of the PIN diodes as a switch. The simulated and measured results are matched well.
A Switchable Tunable Dual-Band Filter Using Varator Diodes for Tuning and Switching
(2017-01-01)
Chou, Po-Jung
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Hu, Chiao-Yi
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Chang, Chi-Yang
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電機工程學系
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Department of Electrical and Computer Engineering
A switchable tunable dual-band filter using varator diodes for band switching and frequency tuning is proposed. The tuning range of first band is from 2.3 to 2.8 GHz and second one is from 1.8 to 2.1 GHz. The proposed dual-band filter is composed of two second-order Chebyshev short-ended hairpin comb filters which embedded a pair of the varators as a switching and tuning elements. The simulated and measured results are matched well.
Broadband Planar Magic-T with Marchand Type Power Divider and Balun
(2014)
Chou, Po-Jung
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Lin, Pei-Chieh
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Lin, Yun-Wei
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Lu, Jhe-Ching
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Chang, Chi-Yang
A new broadband high-order planar magic-T is proposed in this paper. The magic-T is formed by Marchand type power divider and balun. Exact synthesis method based on S-domain highpass prototype using Richard\'s theorem tits the magic-T with the user-defined specifications. By discussing the characteristic impedance of the common element shared by the balun and divider, the magic-T can be designed to match different output impedance. A high-order magic-T with wide bandwidth about 100% and reflection coefficient of -15dB is designed as an example where a combination of microstrip lines, slotlines, double-sided parallel-strip line (DSPSL) and coplanar striplines is applied. The simulation and measurement results are matched well.
Exact Synthesis of Full- and Half-Symmetric Rat-Race Ring Hybrids With or Without Impedance Transforming Characteristics
(2015-12-01)
Chou, Po-Jung
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Lin, Yun-Wei
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Chang, Chi-Yang
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電信工程研究所
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Institute of Communications Engineering
Novel full- and half-symmetric rat-race ring hybrid structures are proposed, in which the impedance transforming property can be implemented. Impedance transformation implies that the impedances of the input and output ports can be different. The conventional even- and odd-mode partition and analysis method cannot be applied to the proposed half-symmetric circuits; therefore, an analysis method is developed. The rat-race ring is exactly synthesized on the basis of a newly deduced high-pass prototype that is based on Richards theorem, which allows the user-defined specifications to be satisfied. Three hybrids are synthesized as examples-a sixth-order full- symmetric hybrid with a bandwidth of 116% and a return loss of 20 dB, a fifth-order half-symmetric hybrid with a 100% bandwidth and 25-dB return loss, and a fifth-order impedance-transforming half-symmetric hybrid with an output port impedance of 70 Omega, a 100% bandwidth, and 20-dB return loss. The first and second hybrids are implemented to verify the method. A comparison of the measured and simulation results indicates good agreement.
Exact Synthesis of Unequal Power Division Filtering Rat-Race Ring Couplers
(2018-07-01)
Chou, Po-Jung
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Yang, Chih-Chuan
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Chang, Chi-Yang
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電信工程研究所
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Institute of Communications Engineering
Exact synthesis of unequal power division filtering rat-race ring couplers is proposed. The power division property results from the half-symmetric core ring structure of the proposed couplers. The proposed core ring was modified from the equal power division rat-race ring in 2015 where the core ring in that circuit is fully symmetric. Due to the half-symmetry of ring and unequal power division characteristics, the signal excitation and circuit partition methods in 2015 cannot be applied. In this paper, the modified signal-excitation method and the source-division technique are proposed to reduce the original four-port rat-race ring couplers into the corresponding two-port networks. These two-port networks can be exactly synthesized by the S-domain filter synthesis method. Alternatively, the simplified design equations are proposed. Using these equations, the rat-race ring hybrid in 2015 can be transformed into the arbitrary power division rat-race ring couplers. Therefore, the final rat-race ring couplers are provided with some user-defined specifications, such as the unequal power division, the input/output impedance transformation, the center frequency, the fractional bandwidth, and the return loss level. Two fifth-order filtering rat-race ring couplers with 3- and 10-dB power division are implemented as examples; in addition, these couplers are with a center frequency of 2 GHz, a fractional bandwidth of 100%, a return loss level of 20 dB, and the input/output impedance transformation of 50/70 Omega. The measured and simulated results indicate good agreement.
X-band Three-stub Filter Embedded SPDT Switch Using Packaged PIN Diodes and Novel Resonators
(2015-01-01)
Tsai, Guo-Ding
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Chou, Po-Jung
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Chang, Chi-Yang
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電機工程學系
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Department of Electrical and Computer Engineering
A Single pole double throw (SPDT) switch using the packaged PIN diodes for X-band application is proposed. The SPDT switch is embedded in two Chebyshev three-stub filters where one of the three stubs is substituted by the PIN diode and peripheral circuits. The high value of parasitic inductance in the package is absorbed by the filter with a proposed novel resonator structure. The simulated and measured results are matched well.