Design of a Decoupling Structure for Mutual Coupling Reduction of LSFPA Antenna of 24 GHz mm-Wave Vehicle-Borne Radar
Antenna structure is one of the core components of millimeter wave radar,and the detection ability of millimeter-wave radar is determined by the performance of antenna.A new decoupling structure based on defected ground and inverted T parasitic elements is proposed to solve the problem of mutual coupling between linear series-fed patch array(LSFPA)antennas of 24 GHz vehicle-borne milli-meter wave radar.The decoupled structure etches two ring-defect ground structures of the same size under the two largest patches of the linear series-fed patch array antenna to adjust impedance matching,and inserts inverted T(T1 and T2)shaped parasitic elements with different sizes between the two nearest and next nearest patches to further reduce the coupling between the patches.Simulation and test results show that mutual coupling of the proposed linear series-fed patch array antenna with decoupling structure is reduced by 36 dB at the center frequency of 24.5 GHz.In comparison with the linear series-fed patch array antenna without decoupling structure,the de-signed decoupling structure effectively reduces the coupling between antennas.