A system-on-package integration of X-band FMCW sensor RF frontend module

A novel system on package (SoP) RF frontend module for X-band frequency modulated continuous wave (FMCW) sensor is presented in this paper for short distance moving object detection. A multifunction RFIC chip realized by typical 1P6M 0.18 ¿m deep n-well CMOS technology, a multilayer 180° hybrid and two embedded ring filters, two sets of antenna arrays, and all other necessary components are all integrated into a miniaturized module no larger than 35mm×35mm LTCC substrates. In addition to the 3.5dBm transmitter output and 6dB receiver conversion gain of the RFIC block, a 7.5dB-gain electric bandgap (EBG) structure backed single arm fractional spiral antenna element is developed for maximizing the detection range within the volume limit of the module. Besides the basic functionality of distance detection, angle detection is also accomplished by comparing the sum and difference patterns of an antenna element pair at receiving end. Each building block has been tested individually for verifying the functionality of the whole module. Good agreements between simulations and measurements have been obtained.