Fourth harmonic image rejection mixer monolithic design
|School||University of Electronic Science and Technology|
|Course||Electromagnetic Field and Microwave Technology|
|Keywords||MMIC Harmonic mixer Image rejection PHEMT|
The monolithic microwave integrated circuits referred to MMIC is an active and passive components produced in the microwave circuits on the same semiconductor substrate . It has the advantages of small size , light weight , high reliability, good stability . The mixer is widely used in the fields of communication , radar , a core component of the receiving system . Based on the the UMS company 0.15um GaAs process design a millimeter wave fourth harmonic image rejection mixer . More difficult to design high-performance millimeter wave local oscillator using harmonic mixer technology to the local oscillator frequency can be reduced to the fundamental frequency of 1 / 2 , 1 / 4 , thereby avoiding the millimeter wave local oscillator design challenges ; mirror suppression technology is particularly important in terms of interference , so the harmonic mixer technology with mirrored suppression technology to combine design mixer is of great significance . At first, the diode circuit design and simulation , simulation results , however , are not ideal ; followed by the application of PHEMT ( pseudomorphic high electron mobility field-effect transistor ) design a resistive fourth harmonic image rejection mixer , the core of which parts double balun and Lange bridge , both amplitude imbalance and phase unbalance plays a decisive role in the final overall circuit simulation results are up to the requirements of the design specifications ( 35 ~ 37GHz RF image rejection when the mirror frequency suppression gt ; 20dB conversion loss lt ; 20dB ; RF and the LO isolation gt ; 30dB) . The test results show that the mixer at the RF input 35 ~ 39GHz, IF output 0 ~ 2GHz frequency conversion loss is less than 20dB image rejection greater than 17.5dB . RF and the LO isolation greater than 38dB.