Browsing by Author "Lin, Chin-Kai"

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A Compact Edge-Fed Filtering Microstrip Antenna with 0.2 dB Equal-Ripple Response
(2009)
Lin, Chin-Kai
;
Chung, Shyh-Jong
;
電信工程研究所
;
Institute of Communications Engineering
A compact microstrip antenna with a second order 0.2 dB equal-ripple response and 4 % fractional bandwidth is proposed. This design follows the synthesis process of the bandpass filter. The radiating patch is fed by a new edge-fed gap-coupling mechanism. The coupling section excites the antenna, and it can be an admittance inverter for the filter design as well. Moreover, it does not occupy any additional circuit area. The proposed antenna has the size of 0.6 lambda(g) x 0.6 lambda(g), where lambda(g) is the guiding wavelength in the substrate. The antenna provides good selectivity, flat in-band antenna gain response, and good out-band rejection. The measurement results agree with the simulated ones.
A Compact Filtering 180 degrees Hybrid
(2011-12-01)
Lin, Chin-Kai
;
Chung, Shyh-Jong
;
傳播研究所
;
Institute of Communication Studies
A novel compact filtering 180 hybrid utilizing coupled resonators is presented. The equivalent-circuit structure is just like a bandpass filter, thus the frequency response is filter-like. The sum and difference port operations respectively correspond to the symmetric and antisymmetric states; therefore, isolation between sum and difference ports is accomplished by geometrical symmetry. The synthesis method of the filtering 180 hybrid is illustrated. The proposed structure is decomposed into one power divider and one balun, which are designed separately. A second-order filtering 180 hybrid prototype centered at 2.4 GHz with 0.2-dB Chebyshev equal-ripple response and 10% fractional bandwidth is demonstrated. The passband insertion loss is about (3.0 + 0.7) dB, and the isolation between the sum and difference port is greater than 20 dB. Magnitude imbalance is less than 1 dB and phase imbalance is within 2 degrees. Good agreement between simulation and experimental results is achieved.
A Compact Filtering Microstrip Antenna With Quasi-Elliptic Broadside Antenna Gain Response
(2011)
Lin, Chin-Kai
;
Chung, Shyh-Jong
;
傳播研究所
;
Institute of Communication Studies
Design, fabrication, and measurement of a compact filtering microstrip antenna with second-order quasi-elliptic broadside antenna gain response are presented. A U-shape radiating patch is excited by a T-shape resonator through an inset coupling structure. The U-shape patch acts as a radiator as well as the last stage of the filter, and the inset coupling structure can be treated as the admittance inverter in filter design. The design procedure follows the circuit approach-synthesis of bandpass filters. The broadside gain of the filtering antenna has two poles in passband and two broadside radiation nulls (zeros) at the band edges for improving selectivity. Compared to the conventional inset-fed microstrip antenna, with a little extra circuit area, the proposed filtering antenna has a flatter passband response, better frequency skirt selectivity, and almost twice wider bandwidth. The measurement result shows a good agreement with the simulations.
A Compact Simple Structured Filtering Antenna Utilizing Filter Synthesis Technique
(2010-01-01)
Lin, Chin-Kai
;
Chung, Shyh-Jong
;
電信工程研究所
;
Institute of Communications Engineering
A compact simple structured filtering antenna and its synthesis method are presented in this paper. The filtering antenna is composed of an inverted-L antenna and a quarter-wavelength transmission line which are modeled by a series RLC resonator and a shunt LC resonator, respectively. Thus, the overall filtering antenna is modeled by the prototype bandpass filter. The detail synthesis procedures are introduced. The filtering antenna is printed on one side of the FR4 substrate that structure is extremely simple. The filtering antenna is designed at 2.45 GHz with 20% bandwidth. The far-field antenna gain is omnidirectional on its H-plane, and it maintains the averaged value around 1 dBi within the passband. The measurement results show good agreement with the simulations.
A Filtering Microstrip Antenna Array
(2011-11-01)
Lin, Chin-Kai
;
Chung, Shyh-Jong
;
傳播研究所
;
Institute of Communication Studies
A new filtering microstrip antenna array is presented. The antenna elements, together with the very compact feeding network, function as a third-order bandpass filter. The feeding network, which consists of one power divider and two baluns, provides the first two stages, and the microstrip antenna elements provide the last stage in the filter design. The equivalent lumped circuit model is analyzed, and the detail synthesis procedure is presented. A third-order filtering 2 x 2 microstrip antenna array is designed at a center frequency of 5 GHz with 3% fractional bandwidth and Chebyshev 0.3-dB equal-ripple broadside antenna gain response. The results from circuit model, full-wave simulation, and measurements agree well. Compared to the conventional patch antenna array, the proposed filtering microstrip antenna array successfully suppresses the unwanted signals in out-of-band, preserves good selectivity at band edges, and retains the flatness of the pass-band broadside antenna gain response.
VALIDITY AND INTERNAL CONSISTENCY RELIABILITY OF A COMPUTERIZED TEST TO ASSESS PRONE EXTENSION IN CHILDREN AGES FOUR TO SIX YEARS
(2010-08-01)
Lin, Chin-Kai
;
Wu, Huey-Min
;
Kuo, Bor-Chen
;
Li, Cheng-Hsaun
;
電控工程研究所
The objective of this study was to develop a computerized test of prone extension to measure performance of prone extension in children 4 to 6 years of age. The participants were selected from kindergartens, comprising 132 boys and 107 girls with a mean age of 5 yr. 2 mo. (SD = 6 mo.). Sensitivity and specificity of the computerized test of prone extension were assessed by comparison with the judgments of an expert, an occupational therapist with more than 20 yr. of pediatric experience, as the criterion standard. The computerized test of prone extension identified children with poor outcomes with a sensitivity of 0.83, a specificity of 0.88, and an accuracy of 0.87. The internal reliability index was 0.81. The computerized test of prone extension could be of value in detecting problems of antigravity posture in prone extension and permitting early intervention to correct it.