RF to IF Dual Downconverting Mixer

This design utilizes Integrated Device Technology's F1100 RF to IF dual downconverting mixer. This F1100 dual channel RF mixer operates with a single 5V supply. The local oscillator input ports are pins 19 and 27 (LO_in and LO_in_alt respectively). It is important to take note that only one LO port can be driven at a time. The RF input ports are pins 1 and 9 (RF_A and RF_B respectively). They are internally matched to a 50Ω impedance. On the other hand, the main mixer differential IF outputs are pins 32 and 33 (IFA- and IFA+), while the diversity differential outputs are pins 13 and 14 (IFA- and IFA+). Pull-up inductors are connected from each of these pins to VCC. This design features dual path for diversity systems which are ideal for multi-carrier systems.

This design is very useful in a wide variety of applications especially in a multicarrier base station receiver for frequency range of 698-915 MHz with high side injection. It offers +41dBm output IP3 with 350mA of ICC and supports IF frequencies from 150 to 450MHz. In typical base station receivers, the mixer limits the linearity performance for the entire receive system. The F1100 with zero-distortion technology dramatically improves the maximum IM3 interference that the BTS can withstand at a desired Signal to Noise Ratio (SNR).