This design features a low power wideband RF synthesizer that is used in GSM receiver cards. It has dual differential and open drain outputs with frequency range of 34.375MHz to 4400MHz(in continuous range). The logic compatibility is 1.8V while the system is running on a single 3.3V supply. It has -143dBc/Hz Phase Noise (PN) performance at 1MHz Offset for every 1.1GHz output. It is also capable of mute function at RF_OUT that is accessible via mute pin or SPI command. It is low power with only 380mW average power consumption while RF_OUTB is not in used.
The design is comprised of 3 major parts. The first part consists of IDT8V97051NLGi wideband RF synthesizer/PLL supports the output frequencies with Voltage Controlled Oscillator (VCO). The temperature compensated crystal oscillator close to the RF input helps in the precision of signal while the other parts are filters that are used in various purposes like minimizing undesired noise. The second part consists of the USB 2.0 high speed to UART/FIFO IC that is used for system interface while the I2C-bus to SPI bridge IC controls the sequences, protocol, and timing of the signal. The last part is power supply management of the system in which it is provided with RC filters in every line to ensure minimal noise are included in the supply.
The design is applicable in multi-carrier, multi-mode Frequency Division Duplexing (FDD) and Time Division Duplexing (TDD) base station radio card. It optimizes multi-service base stations during its service as a local oscillator that generates a large variety of frequencies to mixers while maintaining excellent PN.
For more detail: 8V97051 Low Power Wideband Fractional RF Synthesizer
