Browsing by Author "Gong, J"

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New CMOS 2V low-power IF fully differential Rm-C bandpass amplifier for RF wireless receivers
(2001-12-01)
Cheng, Y
;
Gong, J
;
Wu, CY
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
A new CMOS fully differential bandpass amplifier (BPA) based on the structure of a transresistance (Rm) amplifier and capacitor is proposed and analysed. In this design, the Rill amplifier is realised by a simple inverter with tunable shunt-shunt feedback MOS resistor and tunable negative resistance realised by crosscoupled MOS transistors in parallel with a current source. The capacitor is in series with the input of the Rm amplifier, which realises the filter function and blocks the DC voltage. Under a 2V supply voltage, the post-tuning capability of the gain can be as high as 55 dB whereas the tunable frequency range is 41-178 MHz. The power consumption is 14mW and the dynamic range (DR) is 50 dB. The differential-mode gain is 20 dB and the common-mode gain is -25 dB so that the CMRR is 45 dB. Simple structure, good frequency response and low power dissipation make the proposed bandpass amplifier quite feasible for application in the IF stage of RF receivers.
The design of a 2-V 900-MHz CMOS bandpass amplifier
(2001)
Cheng, Y
;
Wu, CY
;
Gong, J
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
A 900 MHz low-power CMOS bandpass amplifier suitable for the applications of RF front-end in wireless communication receivers is proposed and analyzed. In this design, the temperature compensation circuit is used to stabilize the amplifier gain so that the overall amplifier has a good temperature stability. Moreover, the compact tunable positive-feedback circuit is connected to the integrated spiral inductor to generate the negative resistance and enhance its Q value. The simple diode varactor circuit is adopted for center-frequency tuning. These two improved circuits can reduce the power dissipation of the amplifier. An experimental chip fabricated by 0.5 mum double-poly-double-metal CMOS technology occupies a chip area of 500 x 500 mum(2); chip area. The measured results have verified the performance of the fabricated CMOS bandpass amplifier. Under a 2-V supply voltage, the measured quality factor is tunable between 4.5 and 50 and the tunable frequency range is between 845 MHz and 915 MHz. At Q = 30, the measured S-21 is 20 dB whereas the noise figure is 5.2 dB in the passband. The gain variation is less than 4 dB in the range of 0-80 degreesC. The dc power dissipation is 35 mW. Suitable amplifier gain, low power dissipation, and good temperature stability make the proposed bandpass amplifier quite feasible in RF front-end applications.
The new CMOS 2V low-power if fully differential Rm-C bandpass amplifier for RF wireless receivers
(2000)
Wu, CY
;
Cheng, Y
;
Gong, J
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
A new CMOS fully differential bandpass amplifier (BPA) based on the structure of transresistance (Rm) amplifier and capacitor is proposed and analyzed. In this design, the Fm amplifier is realized by a simple inverter with tunable shunt-shunt feedback MOS resistor and tunable negative resistance realized by the cross-coupled MOS transistors in parallel with a current source. The capacitor is in series with the input of Rm amplifier, which realize the biter function and block the de voltage. Under a 2-V supply voltage: the post-tuning capability of the gain can be as high as 90 dB whereas the tunable frequency range is between 41MHz and 178MHz. The power consumption is It mw and the dynamic range (DR) is 50 dB. The differential-mode gain is 20 dB and the common-mode gain is -25 dB so that the CMRR is 45 dB. Simple structure: good frequency response, and low power dissipation make the proposed bandpass amplifier quite feasible in the applications of IF stage for RF receivers.