Abstract: An apparatus and methods for receiving polarization diverse radio signals. The apparatus includes a coherent light source configured to output an optical carrier signal, a dual polarization antenna, and a nested Mach-Zehnder Modulator. The nested Mach-Zehnder Modulator is configured to receive the optical carrier signal, a first RF electrical signal from a first output of a dual polarization antenna corresponding to a first linear polarization mode and a second RF electrical signal from a second output of the dual polarization antenna corresponding to a second linear polarization mode, modulate the optical carrier signal based on the first RF electrical signal and the second RF electrical signal to generate an upper optical sideband signal, a lower optical sideband signal, and output the upper and lower optical sideband signal separately.

Abstract: The present invention relates to a trocar assembly comprising a cannula (40) and an obturator (1) arranged, in use, to be received within and extend through the cannula (4). The obturator (1) comprises a shaft (2) and a head (4). The shaft (2) is arranged to extend through the cannula (40) and having an external diameter which is less than the internal diameter of the cannula (40). The head (2) is arranged to protrude beyond the cannula (40). At least a portion of the head (4) has an external diameter which is greater than the internal diameter of the cannula (40). Said portion of the head (4) comprises a radially extending cut-out (18) such that the portion of the head (4) is radially collapsible for withdrawal through the cannula (40). The obturator (1) further comprises a locking member (30) which is received within the cut-out (18) to prevent withdrawal of the obturator (1).