Comments
combination of filters and switches is used to solve the non-linearity problems in GSM/W-CDMA transceiver front-end wherein one common antenna is used for both the GSM mode and the W-CDMA mode. In particular, separate Rx/Tx paths and switches in the Rx paths are used to provide cross-band isolation between bands. All of the switches in the transceiver are disposed after the filters in that no switches are disposed between the filters and the antenna. Furthermore, bandpass filters are matched to one common node even if they are only disconnected at the output as long as the impedance at the output can be controlled.
Posted by jahangir1983
combination of filters and switches is used to solve the non-linearity problems in GSM/W-CDMA transceiver front-end wherein one common antenna is used for both the GSM mode and the W-CDMA mode. In particular, separate Rx/Tx paths and switches in the Rx paths are used to provide cross-band isolation between bands. All of the switches in the transceiver are disposed after the filters in that no switches are disposed between the filters and the antenna. Furthermore, bandpass filters are matched to one common node even if they are only disconnected at the output as long as the impedance at the output can be controlled.
Posted by jahangir1983
:This paper describes a 10-MHz bandwidth WLL (Wireless Local Loop) intermediate frequency (IF) transceiver integrated circuit. The chip interfaces between the RF (radio frequency) and the digital modem sections, and performs the IF-to-baseband (Rx) and baseband-to-IF (Tx) frequency conversions. It incorporates two 100-dB VGAs (variable gain amplifiers), two fixed-frequency PLLs, four low pass filters, two 4-bit A/D converters and two 10-bit D/A converters. It has been implemented in a 0.6-μm silicon CMOS process. The PLLs include the VCOs, dividers, phase detectors, and charge pump circuits on chip. The only external requirements are the varactor-tuned LC tank circuit and PLL loop filter circuit. Total supply current is about 57 mA at 3.0-5.0 V
Posted by waqasahmad
The combination of filters and switches is used to solve the non-linearity problems in GSM/W-CDMA transceiver front-end wherein one common antenna is used for both the GSM mode and the W-CDMA mode. In particular, separate Rx/Tx paths and switches in the Rx paths are used to provide cross-band isolation between bands. All of the switches in the transceiver are disposed after the filters in that no switches are disposed between the filters and the antenna. Furthermore, bandpass filters are matched to one common node even if they are only disconnected at the output as long as the impedance at the output can be controlled.
(end of abstract)
Posted by sagitraz
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