Transceiver Integrates RF And IF Performance

A highly integrated RF/IF transceiver that provides the optimum compromise among performance, power, size and cost for use in direct sequence spread spectrum systems, the RF2938 is designed for use in 2.4-GHz ISM band applications, such as wireless LAN and wireless modems. The receive side includes AGC, quadrature mixers and user-programmable I and Q filters. The filter bandwidth (5th order Bessel LPF) can be set from 1 to 35 MHz by connecting the appropriate external resistor to ground. The device can be used with the firm's RF2444 LNA/Mixer to implement a spread spectrum transceiver system. The transmit path also includes programmable filters, IF quadrature mixers and a transmit VGA. The RF2938 includes an on-chip 2.4-GHz up-converter. The mixer output is available to the user and can be connected to the internal RF amplifier. This arrangement is capable of providing 6 dBm (linear) at 2.4 GHz, potentially eliminating the need for an external power amplifier in short-range applications.