  We describe in detail gravitational wave bursts from Primordial Black Hole
(PBH) hyperbolic encounters. The bursts are one-time events, with the bulk of
the released energy happening during the closest approach, which can be emitted
in frequencies that could be within the range of both LIGO (10-1000Hz) and LISA
($10^{-6}-1$ Hz). Furthermore, we correct the results for the power spectrum of
hyperbolic encounters found in the literature and present new exact and
approximate expressions for the peak frequency of the emission. Note that these
GW bursts from hyperbolic encounters between PBH are complementary to the GW
emission from the bounded orbits of BHB mergers detected by LIGO, and help
breaking degeneracies in the determination of the PBH mass, spin and spatial
distributions.
