Please select the most similar patent number from A, B, C and D. Which number is?
A welding system (2) for a metal piece (11) and a coaxial cable (12), comprising: a heating device (21) provided at a processing station and enabling the metal piece (11) or the coaxial cable (12) to enter a contact for heating; a solder feeding device (22) disposed adjacent to the heating device (21) and used for adding solder (13) to a joint of the metal piece (11) and the coaxial cable (12); and a moving and positioning device (25) used for separately clamping and transferring the metal piece (11) and the coaxial cable (12) to the processing station. The present invention also relates to a welding method for a metal piece (11) and a coaxial cable (12). The system and method can well improve the reliability and conduction rate of soldering of a metal piece and a coaxial cable, and can improve production efficiency and reducing production costs.
A: A time domain reflective single end test apparatus and method for a radio frequency co-axial coupler. The apparatus comprises an assembly to be tested (10), a co-axial cable (14), a network analyser (15) and a computer (16). The assembly to be tested (10) comprises a female-to-female radio frequency co-axial coupler (11), a male-to-female radio frequency co-axial coupler (12) and a load resistor (13) which are connected in series. An output end of the network analyser (15) is connected to one end of the co-axial cable (14), and the other end of the co-axial cable (14) is connected to the female-to-female radio frequency co-axial coupler (11) of the assembly to be tested (10). An output end of the network analyser (15) is connected to the computer (16), and the network analyser (15) is used for performing a time domain reflective test on the assembly to be tested (10) so as to obtain a reflective voltage signal of the assembly to be tested (10) and input the measured reflective voltage signal to the computer (16) so as to obtain a fault position of the male-to-female radio frequency co-axial coupler (12). The test apparatus and method can analyse the impedance mismatch problem of a radio frequency co-axial coupler more intuitively and clearly, and can precisely determine the fault position of a radio frequency co-axial coupler.
B: Provided is a method for non-contact overall heating and tin brazing of a metal structural member and PCB, comprising the following steps: placing a workpiece on a drive system and transferring said workpiece to a heating system by means of the drive system, the workpiece being a joint body consisting of a metal structural member, PCB, weld, and a rotation fixture; heating the workpiece by non-contact thermal radiation of the entire body, causing the weld on the workpiece to melt; cooling the workpiece on which heating and welding has been completed, such that the molten weld rapidly solidifies into a desired weld point. The welded components are fixed, weld material is added, the weld is heated, and splitting is performed to establish two different processes, and a fine division of process steps is advantageous to the automation of each of the process steps, achieving modularized management.
C: A multi-slot microwave ablation needle, comprising an antenna radiation area (100) and a water cooling system for the ablation needle. The antenna radiation area (100) comprises a metal needle (110), a transmission area casing (120), and a semi-steel coaxial cable (130); the transmission area casing (120) is made of a high-temperature resistant material having a relative dielectric constant of 28-32, and comprises a stepped through hole; the semi-steel coaxial cable (130) comprises a coaxial cable outer conductor (133), a coaxial cable inner conductor (131), and a coaxial cable insulation layer (132); the coaxial cable outer conductor (133) and the insulation layer (132) of the semi-steel coaxial cable (130) at two positions are stripped, and the two positions are filled with a high-temperature resistant material having a relative dielectric constant of 25-35, so that a first transmission window (122) and a second transmission window (123) are formed in the transmission area casing (120); the stepped through hole of the transmission area casing (120) is divided into two sections; and the semi-steel coaxial cable (130) is fitted in the first section of the stepped through hole, and the second section of the stepped through hole is filled with metal to form a third transmission window (121) in the transmission area casing (120). The ablation needle is provided with three transmission windows (122, 123, 121) to ensure that a hot ablation zone is larger and has a shape closer to a sphere.
D: An electric railway coaxial cable power supply system is composed of a central traction substation SS, a coaxial cable, traction transformers TT, an overhead line system T, a steel rail R, a breaker and the like. The central traction substation SS is connected to the coaxial cable. The coaxial cable and the overhead line system T are erected in parallel. The traction transformers TT are single-phase connecting lines and are distributed at certain intervals along the coaxial cable and the overhead line system T. Primary side windings of the traction transformers TT are connected between an inner conductor IC and an outer conductor OC of the coaxial cable in parallel, and secondary side windings of the traction transformers TT are connected between the overhead line system T and the steel rail R in parallel. By means of the adjacent traction transformers TT, the inner conductor IC of the coaxial cable is connected to the overhead line system T in parallel, and the outer conductor OC of the coaxial cable is connected to the steel rail R in parallel. According to the system of the present invention, the power supply capacity and the voltage level are mainly determined by the coaxial cable, the system is suitable for matching the coaxial cable with the overhead line system T at various voltage levels, and the light suspension and the overall quality improvement of the overhead line system T are facilitated; the coaxial cable is erected along a railway or a subway tunnel without additionally occupying any corridor, interfaces between the railway and the utility grid can be reduced, investment for an external power supply is saved, and management is convenient.
Answer: B