Composite right/left-handed leaky wave antenna with half mode substrate integrated waveguide structure

Composite right/left-handed (CRLH) structure used to design leaky wave (LW) antenna on half mode substrate integrated waveguide (HMSIW) is proposed and investigated in this paper. With the CRLH structure, the antenna can realized continuous beam scanning from endfire to backfire through varying the frequency. The proposed antenna is a planar passive circuit and fabricated by the normal low-cost printed circuit board process. The HMSIW structure contributes to reduce the size of antenna by half compared to the SIW structure. Etching interdigital slots on the HMSIW is equivalent to add series capacitors leading to a CRLH structure. Their radiation characteristic and propagation properties are researched extensively. From numerical simulation, the CRLH HMSIW LW antenna demonstrates scanning angles between -51° to 52° with the frequency ranging from 8.2GHz to 10.5GHz. The return coefficient and insert coefficient are found to be low than -10dB in most cases.