leakage cancelling application_number US 201213359655 A description reference will now be made in detail to the subject matter disclosed which is illustrated in the accompanying drawings the scope of the invention is limited only by the claims numerous alternatives modifications and equivalents are encompassed for the purpose of clarity technical material that is known in the technical fields related to the embodiments has not been described in detail to avoid unnecessarily obscuring the description referring to fig1 a radio altimeter 110 according to the present invention is shown the radio altimeter 110 may include at least one transmitting antenna 104 and at least one receiving antenna 106 surrounded by an antennae housing 108 the transmitting antenna 104 and receiving antenna 106 may be connected to altimeter electronics 102 the transmitting antenna 104 may be configured as a planar array and may be further configured to transmit a modulated signal at a known frequency and phase the receiving antenna 106 may also be configured as a planar array and may be further configured to receive a modulated signal originating from the transmitting antenna 104 reflected off a surface such as the ground the radio altimeter 110 may be installed in an aircraft fuselage 100 the antennae housing 108 may include an antennae divider 112 separating the transmitting antenna 104 from the receiving antenna 106 the antennae.