W-band Broadband Mixer

In modern millimeter-wave communication system, mixer is a very crucial part of the super-heterodyne receiver. Therefore, researches on the W-band broadband mixer never stopped.In the theory part of this thesis,the developments of the W-band mixer at home and abroad were introduced, as well as several important technical indicators of the mixer. Also the principle of single-ended and single balanced structure were analyzed and compared, Came up with the features of planar transmission lines such as microstrip, fin-line, coplanar waveguide and a few transitions between transmission lines.Broad-band integrated circuit mixers using a fin-line-Suspended microstrip hybrid configuration were designed with MA-COM's GaAs Flip Chip Schottky Barrier Diodes MA4E1317 in this thesis. The diode equivalent circuit was built with Agilent ADS, then several transitions and low-pass filter, were simulated and optimized respectively using HFSS, as well as the overall circuit model.Those two different kinds of structures have been fabricated and tested. Test results were as follows: for the first mixer, less than 10dB conversion loss was achieved over 27GHz RF instantaneous bandwidth with the LO at 92.15GHz and the RF swept from 75 to 102GHz. With the RF at 91 GHz, a conversion loss of 7.43dB has been achieved; for the second mixer,a conversion loss of 7 to 10.5 dB was achieved over 26GHz RF instantaneous bandwidth as the RF swept from 75 to 101 GHz. With the RF at 94 GHz, a conversion loss of 8.13dB has been achieved.