Method of and apparatus for matching a load circuit to a drive circuit

A method of matching a load circuit to a drive circuit with a matching network connected between the circuits, one of said circuits being of a first reactive type, said network including:

• and L network having a series arm and a shunt arm, one of said arms being on a side of the L network connected to the other of said circuits, the other of said arms being on a side of the network connected to said one circuit, said other arm including a reactance of a second reactive type, opposite to the first reactive type, comprising measuring the amplitude of a first parameter indicative of the energy in said one arm, measuring the amplitude of a second parameter indicative of the energy in the other arm and the one circuit, measuring the amplitude of a third parameter indicative of the energy in the other circuit, the three measured parameters being of the same type, adjusting the values of the reactances in both arms in unison until the first measured parameter is at least the same magnitude as the third measured parameter, and then adjusting the values of the reactances in both arms in unison until the second measured parameter is slightly greater by a predetermined amount than the first measured parameter, in both of said adjusting steps, the value of the reactance of the other arm being adjusted so that for each unit change thereof there is a much smaller change in the value of the reactance of the arm.

Apparatus for matching a load circuit to a drive circuit, one of said circuits being of a first reactive type, comprising a matching network connected between the circuits, said network including:

• an L network having a series arm and a shunt arm, one of said arms being on a side of the L network connected to the other of said circuits, the other of said arms being on a side of the network connected to said one circuit, said other arm including a reactance of a second reactive type, opposite to the first reactive type, said one arm including a further reactance having a value to provide an approximate match between the circuits;
• means for measuring the amplitude of first and second parameters respectively indicative of:
• (a) the energy in said one arm, and (b) the energy in said other arm and the one circuit, the two measured parameters being of the same type;
• and means responsive to the measuring means for adjusting the value of the reactance in the other arm.

Apparatus for matching a load circuit to a drive circuit, one of said circuits being of a first reactive type, comprising a matching network connected between the circuits, said network including:

• an L network having a series arm and a shunt arm, one of said arms being on a side of the L network connected to said other circuit, the other of said arms being on a side of the network connected to said one circuit, said other arm including a reactance of a second reactive type, opposite to the first reactive type, said one arm including a further reactance having a value to provide an approximate match between the circuits;
• means for measuring the amplitude of first, second and third parameters respectively indicative of:
• (a) the energy in said one arm, (b) the energy in the other arm and the one circuit, and (c) the energy in the other circuit, the three measured parameters being of the same type;
• and means responsive to the measuring means for adjusting the value of the reactance in the other arm.