An SIW Periodic Leaky-Wave Antenna With Dual-Stopband and Grating Lobe Simultaneously Suppressed Using a New Slot-Array Within a Half-Period

This letter proposes a new substrate integrated waveguide (SIW) periodic leaky-wave antenna (PLWA) with dual-stopband and grating lobe simultaneously suppressed, in which a new slot-array structure within a half-period is used per unit cell. A PLWA with low permittivity usually encounters two stopbands (i.e., an open stopband and the next coming stopband) as the main beam scans through broadside and in the forward quadrant. Besides, it also suffers from an unwanted grating lobe caused by the
n
= −2 space harmonic as the main beam scans in the forward direction. In order to simultaneously suppress the two stopbands and the grating lobe, we propose and investigate a new SIW PLWA with a new slot-array structure per unit cell. Such an antenna with a low relative permittivity of 2.2 is demonstrated. It is validated that the antenna can produce a single beam scanning continuously from the backward quadrant to near forward endfire.