Browsing by Author "Dai, Yu-Hsiu"

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A 5.15-5.825 GHz high-gain and low-noise CMOS down-conversion mixer with low-power for WLAN 802.11a
(2013-01-01)
Dai, Yu-Hsiu
;
Jou, Christina F.
;
電信工程研究所
;
Institute of Communications Engineering
This paper presents a 5.15GHz-5.825GHz CMOS down-conversion mixer with high-gain, low-noise, and low-power for WLAN 802.11a receiver. The cascade topology is adopted at the transconductance stage to improve power gain and reduce noise factor. And the inductive peaking technique is implemented at the switching stage to flatten the frequency bandwidth of conversion gain. This mixer is implemented in TSMC 0.18 mu m CMOS process, and the chip size including the test pads is 1.2mm(2). The proposed mixer offers a measured conversion gain from 26.2 to 26.7dB, a flat DSB noise figure from 7.3 to 8dB with IF 10MHz, and input third-order intercept point from 8 to -12dBm, over the whole working range, while consuming 11.32mW from a 1.8V supply voltage.
A Triple-Band Circularly-Polarized Antenna with Tuning Fork Shape Strips
(2012-01-01)
Dai, Yu-Hsiu
;
Lin, Yi-Mao
;
Huang, Jie-Huang
;
Jou, Christina F.
;
電信工程研究所
A new design of triple-band circular polarized antenna is presented. The proposed antenna is achieved using microstrip-fed with one L shape strip line, two circular strips and two circular patches. One circular strip radiates lower band, the other one covers higher band. By adding the circular patches and L shape microstrip the axial-ratio of this proposed antenna has been improved. This antenna operates in three bands which are 2.5GHz, 3.5GHz and 5.2GHz. These three operating bands can be applied for the WiMax and WLAN application. Experimental results show the proposed antenna has good return loss and circular polarization characteristics. The 10dB return loss impedance bandwidths for the band 2.5GHz, band 3.5GHz and 5.2GHz are 33%, 25% and 9.79%, respectively. The 3dB axial-ratio bandwidth are 11.4%, 6.2% and 11.8% with respect to 2.5GHz, 3.5GHz and 5.2GHz, respectively.
A Triple-Band Circularly-Polarized Antenna with Tuning Fork Shape Strips
(2012-01-01)
Dai, Yu-Hsiu
;
Lin, Yi-Mao
;
Huang, Jie-Huang
;
Jou, Christina F.
;
電信工程研究所
A new design of triple-band circular polarized antenna is presented. The proposed antenna is achieved using microstrip-fed with one L shape strip line, two circular strips and two circular patches. One circular strip radiates lower band, the other one covers higher band. By adding the circular patches and L shape microstrip the axial-ratio of this proposed antenna has been improved. This antenna operates in three bands which are 2.5GHz, 3.5GHz and 5.2GHz. These three operating bands can be applied for the WiMax and WLAN application. Experimental results show the proposed antenna has good return loss and circular polarization characteristics. The 10dB return loss impedance bandwidths for the band 2.5GHz, band 3.5GHz and 5.2GHz are 33%, 25% and 9.79%, respectively. The 3dB axial-ratio bandwidth are 11.4%, 6.2% and 11.8% with respect to 2.5GHz, 3.5GHz and 5.2GHz, respectively.