MAX19998: Highest linearity, SiGe downconverting mixer for LTE, WiMAX, and MMDS base stations
Maxim introduced the MAX19998, a fully integrated, 2300MHz to 4000MHz, downconverting mixer with an on-chip LO buffer. Designed using Maxim's proprietary monolithic SiGe BiCMOS process, this device delivers an unparalleled combination of linearity, noise performance, and component integration over an exceptionally wide band of operation. A single IC provides a fully integrated downconversion channel, with 24.3dBm (typ) of IIP3, 8.7dB (typ) of conversion gain, and a 9.7dB (typ) noise figure.Additionally, the MAX19998 offers an industry-best 2RF - 2LO spurious rejection of 67dBc for an RF level of -10dBm, and 62dBc for a level of -5dBm. This device is designed specifically for 4G wireless-infrastructure applications in which high linearity and a low noise figure are critical for enhanced receiver sensitivity and blocker immunity. The device supports both high- and low-side LO injection architectures for 3.1GHz to 3.9GHz LTE and WiMAX(TM) base stations; the MAX19998 can also be configured for 2.3GHz to 2.9GHz LTE, WiMAX, and MMDS high-side LO injection architectures.
As a complete SiGe downconverter, the MAX19998 integrates a state-of-the-art mixer core, two amplifiers, two baluns, and dozens of discrete components. The device's 8.7dB conversion gain enables the elimination of a complete IF amplifier stage within the receiver lineup. The MAX19998's outstanding 2RF - 2LO performance can also ease the filtering requirements of close-in harmonics, thus leading to simpler, more cost-effective filter designs. Through this combination of integration and performance, the device reduces downconverter solution size by a factor of 2x, and the discrete part count by 34%.