Leaky-wave antennas (LWAs) have gained increasing attraction in communications systems, especially at mmWave band due their high gain, low profiles, and simple feeding networks. However, their application in these systems has been limited due to their inherent dispersive nature that causes gain losses at the fixed angle. Although attempts have been made to overcome this limitation, the existing solutions often suffer from either drop in directivity, prohibitive complexity, or higher losses. To overcome these drawbacks, the proposed solutions include the use of a frequency-dependent Huygens metasurface to reduce the beam squint by nearly half [C.Pfeiffer and A.Grbic, IEEE Trans.Antennas Propag., 63, 7, 3248-3253, 2015], or a complementary-dispersive prism lens to achieve an almost complete cancellation [L.Wang, J.L.Gomez-Tornero and O.Quevedo-Teruel, IEEE Trans.Antennas Propag., 66, 6, 3110-3118, 2018]. Even though these two schemes are similar in concept, the latter is more flexible and can be applied to a larger number of LWAs. The prism solution has been experimentally demonstrated with pin- and hole-type groove-gap waveguide (GGW) technology at X- and V-band.