Comlent delivers CMOS TD-SCDMA transceiver

October 31, 2006

Comlent Technology announced that it starts sampling RFIC transceiver and analog baseband (ABB) chipset in advanced CMOS technology for TD-SCDMA, the world's first of its kind.

The chipset includes a single chip transceiver CL4020 that uses a direct-conversion architecture that integrates the voltage-controlled oscillator (VCO), fractional-N phase-locked loop (PLL), a receiving channel select filter and a transmit driver amplifier and an analog baseband (ABB) chip CL4520 that uses digital signal processing (DSP) to compensate for the imperfections in the analog channel-select filter and to perform dc-offset cancellation. The transmit channel achieves the root mean square (RMS) of the error vectors, EVM, of less than 4%. The phase locked loop integrated phase noise from 1KHz through 640KHz achieves 0.85 degree and noise figure of whole receiving channel is below 4dB, to name a few performance indicators. The testing was conducted in Agilent-Comlent TD-SCDMA RF Labs, the only such RF testing lab for TD-SCDMA in Asia. Nearly a dozen inventions have been disclosed during the development of this chip set. Most of them are being filed for patents in both China and the US.

Before this, TD-SCDMA transceivers provided by two foreign companies were both BiCMOS technology based and cover only one of the two allocated frequencies (1880MHz-1920MHz and 2010MHz-2025MHz) to TD-SCDMA in China. CL4020 is world's first dual-band CMOS TD-SCDMA transceiver that also lifts China's final bottleneck of domestic TD-SCDMA equipment and chip supplying chain. RF transceiver has been identified as the bottleneck of domestic industrial base by China for both TD-SCDMA and other modern wireless communications. The technical report of CL4020 has been accepted by IEEE International Solid State Circuit Conference (ISSCC), the show case chip design conference.