Suppressing Open Stopband for Terahertz Periodic Microstrip Leaky-wave Antennas

This paper reports on a periodic microstrip Leaky-wave antenna (LWA). The open stopband issue is suppressed by altering the unit cell using a matching stub. The developed LWA is based on a grounded InP-substrate of 50 µm and has been fabricated and characterized between 0.23 to 0.33 THz. The dispersion diagram of the designed unit cell shows enhancement of the attenuation constant at the broadside frequency of 0.273 THz and about 50% less deflection at the broadside region on the Bloch impedance curves, consequently better impedance matching at the input. The simulated scattering parameters of the proposed LWA show that the return loss S
11
is below 17 dB except for the broadside, which has a value of 13.8 dB. Furthermore, the beam steering capabilities of the antenna are simulated in the WR3.4 band and confirmed experimentally between 0.26 and 0.33 THz proving the beam direction to steer from −12° to +33°, respectively.