  We report on direct measurements of the electronic shot noise of a quantum
point contact at frequencies nu in the range 4-8 GHz. The very small energy
scale used ensures energy independent transmissions of the few transmitted
electronic modes and their accurate knowledge. Both the thermal energy and the
quantum point contact drain-source voltage Vds are comparable to the photon
energy hnu leading to observation of the shot noise suppression when
$V_{ds}<h\nu/e$. Our measurements provide the first complete test of the finite
frequency shot noise scattering theory without adjustable parameters.
