| The Monolithic Microwave Integrated Circuits (MMICs) are microwave integratedcircuits with both active devices and passive structures fabricated on onesemi-conductor. As the development of microwave circiut techonolgy, the demand ofsmall size, low weight millimeter wave transicever is more and more high. Integratedthe mixer on Monolithic Microwave Integrated Circuits (MMIC) would make it havethe advantages of small size, light weight, high reliability and stability and so on.MMICs are widely used in electronic warfare, missile guidance, phased-array radarsystem and other military field and also widely used in civil field, such as mobilephone,the wireless local area network and global positioning system.In Millimeter-wave band, it’s difficult to design a LO signal with highquality. Harmonic mixer can reduce the LO frequency to be half or quarter,avoiding the design of LO source. Image rejection technology plays a greatimportant part in the anti-jamming. Combining harmonic mix technology andimage rejection technology has great significance.A ka-band quadruple subharmonic image rejection mixer is developed on anadvanced0.15um GaAs process. The passive structure simulated by the full-wavemethod, guarantee the magnitude imbalance and phase imbalance meet the requirementof specification. The simulated S parameter result and the FET model are co-simulatedin schematic simulation.This paper using Wilkinson power splitters provides the LO signal and using Langebridge provides input of RF signal for two mixing units. To reduce area of the chip, theoutput of IF are two quadrature signal, and image rejection IF synthesis output using anexternal bridge. The simulation results show that the conversion loss of mixer A34~36GHz is less than18.5dB, the IRR is better than25dB.The disadvantage of using the inverse parallel diodes designing mixer is poorisolation. We design a bandstop filter in the RF input, so the LO-to-RF isolation is betterthan48dB. All of the results meet the requirement. |
PDF Full Text Request