Microstrip travelling wave combline array antenna with reflection compensation

Abstract

A microstrip travelling wave combline array with reflection compensation is proposed and demonstrated. A compensation stub is used to minimise the cumulative reflection and the sidelobe degradation at broadside. To simplify the compensation design, two same radiating stubs are grouped together to form a pair. Two linear arrays with and without compensation are designed and compared. A fabricated 24 GHz array exhibits a return loss of −22.1 dB and the highest H-plane sidelobe level of −20.2 dB at broadside.