A 3.0 V 2 GHz transmitter IC for digital radio communication with integrated VCOs

The digital European cordless telecommunication (DECT) standard applies to business as well as to the consumer market. Therefore cost effective solutions are required that are able to operate directly from a 3-cell power supply. A transmitter for digital data transmission is realized on a 7.5 GHz bipolar process. The IC, together with a CMOS PLL, constitutes the complete frequency synthesizer. The IC is suitable for both portable and base stations of FSK digital mobile radio, especially cordless phone systems from 1.6 to 2 GHz including DECT, wireless LAN, wireless local loop or any other system using FSK modulation. The design is optimized with respect to power supply, low current consumption, frequency stability and phase noise. No previously-reported transmitter IC includes VCOs and is capable of operating directly from a 3-cell supply. The IC presented here consists of two 800-1000 MHz VCOs, a 64/65 prescaler, a low drop voltage regulator, a frequency doubler, reference current generation, and power down and switching logic.