Connector for coaxial cables

#This invention relates to a connector for interconnecting small coaxial cables, and more particularly for interconnecting small coaxial cables between integrated circuit modules, or hybrid modules, through a conductive wall.

#Great advances have been made in the field of microelectronics. Electronic components have been drastically reduced in size allowing for smaller and smaller functional circuits, such as integrated circuits (IC's) and circuits of hybrid ceramic substrates. A large number of these circuits are used in units operating at Radio Frequencies (R.F.).

#The interconnections between R.F. units are accomplished with semi-rigid coaxial cables and R.F. connectors. The trend has been to reduce size of the connectors.

#FIG. 1 is an exploded view showing a three-part connector according to the present invention.

#FIG. 2 is a side view in elevation of the connector of FIG. 1 assembled for connection of a first coaxial cable to a second coaxial cable through a conductive wall.

#FIG. 3 is a sectional view of the assembled connector of FIG. 1 taken along the line 3--3 of FIG. 2.

#Referring to FIG. 1, the three parts of a connector made according to the present invention are: a connector housing 10 having a cylindrical body portion 11, a base portion 12, and a tubular extension 13; a sleeve 14 which fits inside the body portion; and a threaded cap 15 which screws into the body portion to secure the sleeve inside the body portion against an annular shoulder 16 in the body portion. A centered aperture 17 in the base portion 12 is of just sufficient diameter to receive the insulation and center conductor of a first coaxial cable. The tubular extension 13 has an internal diameter just large enough to receive the outer conductor of the coaxial cable. All parts are preferably made of brass and gold plated.

#The body portion 11 has a slot 18 on one side. The slot is rounded at one end with a radius just sufficient to receive the outer conductor of a second coaxial cable, with the coaxial cable resting on the shoulder 16 inside the body portion. For example, for a cable having an outer conductor diameter of 0.034 inch (outside diameter), the slot has a width of from 0.032 to 0.034 inch, with a full radius of half that width. The upper end of the slot is open, and the corners of the open end are rounded to facilitate placing a coaxial cable in the slot. The sleeve 14 is also provided with an open slot 19 of a width and depth just sufficient to fit over a cable in the slot 18. For example, for the 0.034-cable, the slot 19 will have a width of 0.034 .+-. 0.001 inch, and a depth of from 0.032 to 0.034 inch. After a cable is inserted in the slot 18, the sleeve is inserted into the body portion with the slot 19 placed over the cable. Then when the cap 15 is screwed into place, the cable is crimped and secured in place by the sleeve.

#Before the connector is assembled as just described with a cable in the slot 18, a first coaxial cable is prepared for insertion into the tubular extension 13 by stripping off the outer conductor for a length equal to the distance from outside the base portion 12 to about the center of the body portion 11. The insulation is then stripped for nearly that length. The coaxial cable thus prepared is then inserted into the tubular section 13 and body portion 11 with the edge of the outer conductor against the base portion, and the insulated inner conductor protruding through the base portion with the bare inner conductor extending into the center of the body portion to a point just above the radial center of the slot 18. The second coaxial cable is then prepared by stripping the outer conductor a length about equal to the inner diameter of the annular shoulder, and stripping the insulation to very near the same length. The bare inner conductor of the second coaxial cable is then bent into a loop. As the second coaxial cable is placed in the slot 18, the loop is placed over the end of the inner conductor of the first coaxial cable inserted through the extension 13. The loop is then soldered to the end of the inner conductor thus looped using regular solder (melting temperature approximately 460.degree. F.) Once that is done, the outer conductor of the first coaxial cable is soldered to the tubular extension 13 using low temperature solder (below 400.degree. melting temperature). After the sleeve 14 is inserted, the cap 15 is screwed in until it is tight.