thereof cap member 72 additionally includes a plurality of rearwardly projecting curved latch arms 76 each provided with free end portion 78 equipped with cooperating locking latches 80 intended to releasably engage the groove recess 30 provided in lip 28 on dielectric housing 18 to secure the exterior module 14 in a fully assembled condition cap member 72 includes a plurality of curving slots 82 defined radially inwardly from an edge portion thereof which are adapted to receive the raised edge portions defined between adjacent notches 48 in first shroud member 42 in the fully assembled condition as shown in fig2 and 4 the second major surface 84 of resonator 66 is positioned for flush mounting in face to face contact against the outside surface of vehicle window 12 in accordance with the preferred embodiment depicted in fig1 4 a means for mounting the exterior module 14 to the vehicle window 12 preferably comprises an adhesive pad material 86 having adhesive bonding capabilities disposed on opposed surfaces thereof a preferred adhesive pad 86 comprises an acrylic foam adhesive available from 3m company in accordance with this invention the new and improved antenna apparatus 10 additionally comprises an interior module 16 composed of component elements very similar to those comprising the exterior module 14 more particularly and as best shown in fig1 4 the interior module 16 includes a second dielectrical housing 90 adapted to receive a second electrically conductive shroud member 92 to define a shielded cavity 94 within the interior module 16 a planar printed circuit substrate 96 provided with an electrically conductive region 98 thereon is provided which also includes a positioning pin 99 extending therefrom a second dielectrical resonator 100 is provided within the shielded.