An integrated LTCC AIP for millimeter wave wireless receiving system

This paper demonstrates a novel highly integrated LTCC MMW passive receiving front-end which consists of antenna array, feed network and embedded band pass filter. The above passive components were co-designed as an antenna-in-package (AIP) solution for millimeter wave wireless system. Firstly, 2×2 linear patch antenna array with air cavity had been designed. Its maximum gain was increased 2.9 dB by adopting a novel embedded air cavity. Secondly, a 3-pole miniaturized hairpin filter which was composed of three double layer resonators had been co-designed with the feed network. The filter exhibits an insertion loss of 1.9 dB and a 3 dB bandwidth about 8.1% at the center frequency of 34 GHz. Finally, the above antenna and filtering network were co-designed as a 3-D wireless receiving front-end. In the integrated structure, via fences were introduced to suppress parasitic modes. The measured maximum gain of the array antenna is 14.3 dB and its impedance bandwidth (VSWR<2) is 2.8 GHz(32.9~35.7 GHz) with the filtering feed network. The excellent overall performance of the novel array antenna shows great potential as a fully integrated passive front-end solution for a Ka-band wireless system.