Browsing by Author "Ho, Tan-Hsiung"

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A 2-D Amplifying Array Using Multi-Ported Aperture-Coupled Patch Antennas
(2009-07-01)
Ho, Tan-Hsiung
;
Chen, Wei-Jen
;
Chung, Shyh-Jong
;
電信工程研究所
;
Institute of Communications Engineering
This paper proposes a new circuit-fed 2-D amplifying array architecture using the multi-ported aperture-coupled patch antennas. The power distribution achieved by this array is formed by stacking three kinds of basic cells repeatedly. Each cell, which serves as a radiator and also a power relay, has a multi-ported patch antenna and one or two amplifiers. The signal transmission coefficient of the cell from the input port to the output port is designed with a power level of 0dB and a phase of 360 degrees. An X-band 4 x 3 element array with uniform amplitude distribution is demonstrated. The measured results, such as the antenna gain and the radiation patterns, agree very well with the predicted ones, due to the precision design of the basic cells. The measured gain of the antenna array is 27.7 dBi(A) at the frequency of 10.4 GHz on the H-plane, with a half-power beamwidth of 14 degrees in the H-plane and 16 degrees in the E-plane.
A compact 24 GHz radar sensor for vehicle sideway-looking applications
(2005)
Ho, Tan-Hsiung
;
Chung, Shyh-Jong
;
電信工程研究所
;
Institute of Communications Engineering
A compact 24 GHz short range radar sensor for sideway-looking applications is designed within a dimension of 60 x 45 x 30 mm(3). This dimension is acceptable to be integrated into the right/left mirror of a small automobile. The measurement result of the radar RF circuits shows a maximal output power of 5 dBm and phase noise better than -80 dBc/Hz within the whole operation frequency from 24 to 24.25 GHz. The integrated sensor together with the DSP gives a detection range of 15 meters with distance and speed resolution of 0.75 meter and 2.5 km/hr respectively.
Design and Measurement of a Doppler Radar With New Quadrature Hybrid Mixer for Vehicle Applications
(2010-01-01)
Ho, Tan-Hsiung
;
Chung, Shyh-Jong
;
電信工程研究所
;
Institute of Communications Engineering
This paper presents a novel Doppler radar sensor architecture with a quadrature hybrid mixer. Consisting of four branch-line couplers, two 45 degrees delay lines, and four Schottky diodes, the quadrature hybrid mixer demonstrates high transmission efficiency to pass the power from a local oscillator (LO) to an antenna without wasting received power at the oscillator port. A quadrature Doppler radar system is also implemented with the proposed quadrature hybrid mixer and defected-ground-structure LO. Compared to a conventional quadrature radar, the received power of the proposed architecture is enhanced by 3.3 dB when the LO power is 10 dBm, and is enhanced by 16.2 dB when the LO power is reduced to 0 dBm. Additionally, the improvement in received power is attributed to the improved transmission and lower receiving loss than that of the conventional ones. Capable of determining speeds lower than 0.05 km/h, which corresponds to a 1-Hz Doppler shift. The proposed Doppler radar architecture can identify the direction of the displacement due to use of the quadrature technique.