Abstract A termination for terminating or absorbing a signal transmitted through a transmission line is disclosed as comprising a transmission line having a short circuit thereacross and a thin film of a resistive material disposed within the transmission line approximately one-fourth of a wavelength of the transmitted signal from the short circuit to thereby absorb the signal energy. More specifically, the ratio of the bulk resistivity of the thin film to the thickness of the thin film is selected to be substantially equal to the characteristic impedance of the transmission line thereby ensuring substantially complete energy absorption of the transmitted signal. The thin film is disposed upon a thermally conductive member made of an illustrative material such as beryllium oxide and which not only exhibits a high conductivity but also presents low losses to signals transmitted therethrough. In order to more efficiently dissipate the generated thermal energy, a suitable fluid coolant such as air or water may be directed past the short circuit.
Apparatus for absorbing energy frOm a signal transmitted along a transmission line having a characteristic impedance, said apparatus comprising: a short circuit means disposed across said transmission line; b a film disposed across substantially the entire cross-section of said transmission line; c thermal conduction means disposed in intimate thermal relation with said film for efficiently conducting the thermal energy absorbed by said film from said film to said short circuit means; d said film being disposed a distance N 1/2 /4 from said short circuit means where N is an odd integer and lambda is the wavelength of the signal transmitted in said thermal conduction means; and e matching transformer means disposed within said transmission line in front of said film, said film having an impedance substantially equal to the reduced impedance of said transmission line as transformed by said matching transformer means.
Claim 2
Dependent Claim
143 words
Apparatus for absorbing energy frOm a signal transmitted along a transmission line having a characteristic impedance, said apparatus comprising: a short circuit means disposed across said transmission line; b a film disposed across substantially the entire cross-section of said transmission line; c thermal conduction means disposed in intimate thermal relation with said film for efficiently conducting the thermal energy absorbed by said film from said film to said short circuit means; d said film being disposed a distance N 1/2 /4 from said short circuit means where N is an odd integer and lambda is the wavelength of the signal transmitted in said thermal conduction means; and e matching transformer means disposed within said transmission line in front of said film, said film having an impedance substantially equal to the reduced impedance of said transmission line as transformed by said matching transformer means.
Claim 3
Dependent Claim
24 words
Apparatus as claimed in claim 1, wherein said film is vacuum deposited upon said thermal conduction means to provide an intimate thermal relation therebetween.
Claim 4
Dependent Claim
20 words
Apparatus as claimed in claim 1, wherein said film comprises a resistive ink intimately bonded to said thermal conduction means.