Abstract: A tubular reinforcement element between two hollow tubular members includes an internal lug located internally of the open end of the one hollow tubular member. The internal lug includes a slotted side wall of the same configuration as, and bonded to the inner face of, the open end of one hollow tubular member, and a concave end wall integrally formed with the side wall and extending across the open end of the one hollow tubular member. The end wall of the internal lug has a concave surface complementary and bonded to the curved external surface of the second tubular member.

Abstract: A waveguide-fed microwave system particularly for cavity-backed spiral antennas for the Ka band comprises a waveguide transmission line; a microwave device having a pair of balanced, parallel feed wires; and a doubled tapered ridge transformer directly connecting the waveguide transmission line to the balanced, parallel feed wires of the microwave device providing a direct symmetrical transition between the waveguide transmission line and the microwave device.