Broadband Modulator And Demodulator Enable Direct Conversion Cellular Basestations
ADI is extending its RF portfolio with the industry’s highest performance broadband direct conversion radio solution: the ADL5375 I-Q modulator and companion ADL5382 I-Q demodulator. With the industry’s broadest operating frequency ranges, the ADL5375 and ADL5382 devices enable equipment designers to implement and standardise on solutions that address the wide range of operating frequency bands and standards, including GSM/EDGE, CDMA 2000, and W-CDMA, eliminating the need to select a modulator or demodulator for each cellular standard and operating band.
Furthermore, designers can now implement one common radio platform for cellular standards as well as broadband wireless 802.16 WiMAX standards, which are increasingly being designed using direct conversion radio architectures.
The ADL5375 offers the industry's highest dynamic range across the broadest frequency range—400 MHz to 6 GHz—a key attribute for direct up conversion transmitter architectures. The ADL5375 combines the industry’s highest linearity with 24-dBm output IP3, the highest linear output power with +10-dBm P1dB, and a low –161-dBm/Hz noise floor. The ADL5375 provides unadjusted sideband suppression of –55 dBc and unadjusted carrier feed-through of –41 dBm, helping to eliminate the need for calibration circuitry among the most demanding of applications within cellular 2G and 3G radios. In addition, the ADL5375 allows the user to shut down the transmitter, simplifying receiving of small signals in time division applications, such as WiMAX and TDS-CDMA.
The ADL5382 covers the RF frequency range of 700 MHz to 2.7 GHz, offering the industry’s highest dynamic range with the highest linearity specifications, exemplified by second and third order intercept point specifications of 60-dBm IP2 and 30-dBm IP3, and highest input compression of 13-dBm P1dB. Combining these key specifications with the ability to handle the highest of interference signals with minimal noise contributions ensures that the receiver dynamic range is maintained, a critical requirement for direct conversion receivers and now practical across the ADL5382’s broad operating frequency range. With integrated baseband output amplifiers, the ADL5382 reduces external parts count and simplifies subsequent filter design. Furthermore, the ADL5382 provides approximately 5 dB of conversion gain, helping to minimize the gain requirements of the receiver front end.