Nonreciprocal device having heat transmission arrangement
An isolator with resistive termination and carbon steel housing wherein required magnetic performance is combined with improved efficiency of transmission of heat from termination to the heat sink. The improvement is achieved due to the copper/aluminum plug that mechanically and electrically connects the soldering base of termination to the base of isolator, which in operation is installed on the heat sink. The plug is pressed into the housing from the base side to provide tight coplanarity tolerance to exposed end of the plug and the base without any secondary machining. The termination is soldered to the opposite end of the plug, which is flush to or slightly above the top surface of the housing. Thus, magnetic flux required for operation of isolator is looped through a material having good magnetic susceptibility, and heat from the termination is transmitted to the heat sink through a material having high coefficient of heat transmission. Another embodiment of the structure is also described in this disclosure. In second embodiment, the entire housing is made of copper/aluminum, but a magnetic chamber of carbon steel supporting the magnetic loop is pressed into the housing. The termination is soldered directly to the housing and, therefore, the same efficiency for the heat dissipation as for the preferred embodiment is achieved.
1. A nonreciprocal device having heat dissipating arrangement, comprising:
a housing having a mounting base, a top surface, a chamber with a cover;
a termination having a soldering base, a resistive element;
a central stack composed of magnet, ferrite and center conductor situated inside said chamber and having leads extending outside said chamber, one of said leads making electrical contact with said resistive element of said termination to set up an isolator, wherein said housing made of material with good magnetic susceptibility, having a through hole perpendicular to said mounting base and located right under said termination, said hole is completed with a plug made of material having a high coefficient of heat transmission and said soldering base of said termination is mechanically and electrically connected to said plug to provide heat transmission and grounding.
2. A structure as recited in claim 1 , wherein said plug is pressed into said hole in said housing from said mounting base to be flush with said mounting base and from being flush to slightly above position relationship with said top surface of said housing.
3. A structure as recited in claim 1 , wherein said soldering base of said termination is secured to said top surface of said housing and said plug by solder.
4. A structure as recited in claim 1 , wherein said housing material is mild carbon steel.
5. A structure as recited in claim 1 , wherein said plug material is copper.
6. A structure as recited in claim 1 , wherein said plug material is aluminum.
7. A structure as recited in claim 1 , wherein said chamber is closed by said cover which is screwed on said housing.
8. A structure as recited in claim 1 , wherein said chamber is closed by said cover which is soldered to said housing.