S-band double balanced mixer design

Mixers have a critical importance on designing receiver and transmitter structures. Mixers are one of the most important elements that determine system performance in radar and electronic warfare. For this reason, the performance requirements of mixers are also increasing with the developing technology. Mixers with a lower conversion loss and a higher compression point allow the system to directly increase the dynamic range. For this reason, low-cost mixer designs have become important in addition to high conversion efficiency that can operate in a wider frequency band. Because of the low cost and high performance requirement, Schottky barrier diodes are now highly preferred in mixer design. In this study, it was aimed to design a double balanced mixer which is planned to work in S-Band. Since the mixer was designed in a star topology, the Marchand Balun design was also realized. The conversion loss in the 2-4 GHz frequency band is in the range of 7-9 dB. LO/IF isolation is 25 dB, RF/IF isolation is 30 dB, LO/RF isolation is over 40 dB. The IF bandwidth is measured 1 GHz and for +5 dBm LO drive level P1dB is measured 0 dBm and IP3 is measured 9 dBm.