1.9 GHz Downconverter for Cellular Infrastructure Application with Integrated IF Amplifier - App Note

Modern digital communication systems impose the requirement for high linearity on receivers. Superheterrodyne receivers with high Input IP3 often require the use of mixer with high IP3. Although mixers designed using Schottky diodes are proven to be able to achieve high input IP3, most often such designs require high LO power for proper mixer operation and a LO buffer or amplifier is often necessary to provide sufficient LO signal drive level. The drawbacks of such an approach will be higher current consumption due to additional LO buffer and increased circuit complexity. As with the Avago Technologies' IAM-92516 (High Linearity Passive GaAs FET mixer) having an integrated LO buffer, the IAM-93516 is essentially an integration of the IAM-92516 with high linearity IF amplifiers. This higher level of integration makes the IF chain design more compact and requires less board space. The IAM-93516 is fabricated using Agilent's Ephemt process for superior performance. Using a +5V supply, typical LO input power required for IAM-93516 is less than 0 dBm to achieve a typical Input IP3 of +23 dBm and conversion gain of about 9 dB. Typical current consumption of the device is around 100 mA.