Study On Microwave Image Frequency Rejection Mixer

With the repaid development of microwave technology, the requirement of performance on microwave mixer by microwave systems such as modern radar and communications become higher and higher . Especially , with the wide use of the low noise microwave receiver model of "low noise amplifier - mixer - intermediate frequency amplifier" , the rejection to image frequency interference has become the last problem how to make the whole receiver's noise low and resist interference. Microwave image frequency rejection mixer can achieve wonderful image frequency rejection even in the condition of wide band and low intermediate frequency.and it makes receiver very small. It will be very useful tomorrow.This paper describe mixer diode , microwave mixer's operational principle , some main parameters ; analyse various types of circuit framework of microwave mixer and how to measure its parameters . Then the problem of how to design a image frequency rejection mixer is analysed in-depth . At last, by the aid of Ansoft corporation Serenade 8.5 software , we design and fabricate a X band image frequency rejection mixer . When tested , it give good performance . We find practical test results are in accord with the results optimized by software , which prove that the circuit framework choosed is right , and the software of Serenade 8.5 is useful in designs of microwave circuits .