Browsing by Author "Hsieh, MY"

Now showing 1 - 4 of 4

Bandpass filters with resistive attenuators being located at 2(nd) and 4(nd) spurious pass-bands
(2004)
Hsieh, MY
;
Wang, SM
;
Chang, CY
;
電信工程研究所
;
Institute of Communications Engineering
In this paper, a novel resonator consisting of one half-wave transmission line and the resistive attenuator is proposed to build BPF (bandpass filter) with good stop-band suppression. The resonance characteristics of this type of resonator are intuitive through the ABCD matrix analysis. By means of utilizing the conventional design methodology for parallel coupled-line based BPF, the newly proposed filters can be easily realized by inserting attenuator in coupled-line filter. To confirm the validity of the technique, filters of orders-2 BPF centered at 2.25 GHz with a 5% FBW (Fractional Bandwidth) and orders-3 BPF centered at 2.05 GHz with a 12% FBW were used. Successfully, filters in this paper revealed the 2(nd) spurious response of at least 30 dB insertion loss.
Compact and wideband microstrip bandstop filter
(2005-07-01)
Hsieh, MY
;
Wang, SM
;
交大名義發表
;
National Chiao Tung University
A novel one-section bandstop filter (BSF), which possesses the characteristics of compact size, wide bandwidth, and low insertion loss is proposed and fabricated. This bandstop filter was constructed by using single quarter-wavelength resonator with one section of anti-coupled lines with short circuits at one end. The attenuation-poles characteristics of this type of bandstop filters are investigated through TEM transmission-line model. Design procedures are clearly presented. The 3-dB bandwidth of the first stop-band and insertion loss of the first passband of this BSF is from 2.3 GHz to 9.5 GHz and below 0.3 dB, respectively. There is good agreement between the simulated and experimental results.
Microstrip directional coupler with nearly ideal TEM coupler performance
(2005-05-26)
Wang, SM
;
Hsieh, MY
;
Chiang, CH
;
Chang, CY
;
電信工程研究所
A meandered parallel coupled-line structure is proposed to achieve high directivity within a wide bandwidth. By properly increasing the meandered parallel coupled-line sections, the high-directivity band-width becomes much wider. An example coupler is fabricated to verify the theory. More than 50 dB of isolation is achieved over a bandwidth of zero to twice centre frequency.
Miniaturized spurious passband suppression microstrip filter using meandered parallel coupled lines
(2005-02-01)
Wang, SM
;
Chi, CH
;
Hsieh, MY
;
Chang, CY
;
電信工程研究所
A novel meandered parallel coupled-line structure is proposed to suppress the first spurious passband of a microstrip bandpass filter. The meandered parallel coupled line can equalize the modal transmission phases at any interested frequency such as first spurious passband frequency due to its dispersive response. Several filters are designed and fabricated on a substrate with a dielectric constant of 10.2 and a thickness of 50 mil (1.27 mm) to demonstrate the validity of the proposed method. The example filters are chosen to be of large fractional bandwidth and with a relatively high dielectric-constant substrate where, in these cases, the first spurious passband near twice of the passband frequency (2f(o)) seriously degrades the conventional parallel coupled filter's upper stopband performance. The upper stopband performance of the proposed filters drastically improves that the measured first spurious passband are suppressed to better than -50 dB for all example filters. Besides, a meandered coupled line not only suppresses the filter's first passband, but also largely shrinks its length. The characteristics of the proposed structure and the design procedures of the filter are described in detail.