CMOS IF transceiver for narrowband PCS

Integrated IF transceivers can be used to reduce the size and power consumption of portable radios. The IF transceiver described is designed for narrowband PCS applications, such as two-way paging. This design uses novel signal processing techniques in order to minimize power consumption and analog complexity. The receive section converts a 21.4 MHz IF signal (8 kHz BW) to a digital complex baseband signal. The transmit section accepts a digital complex baseband signal and outputs a 60.4 MHz IF signal (8 kHz BW). The IF transceiver also integrates several functions to control external RF circuitry. These functions include DACs for frequency control of the crystal reference and power control of the transmit PA, a temperature sensor, a general purpose ADC, and general purpose programmable digital inputs and outputs.