Double tuned circuit for distributed lumped capacitance observe coils

Claim 1

A double tuned, split inductor, balanced circuit probe for NMR apparatus comprising: (a) at least a pair of H-shaped members configured in combination to exhibit substantially cylindrical shape, said H-shaped members each having a central portion parallel to the axis of said cylindrical shape and a pair of arm portions and a pair of leg portions, said arm and leg portions of respect H-shaped members spaced apart and communicating between adjacent leg portions and arm portions through respective capacitive elements disposed therebetween, (b) said arm portion connected through respective trap inductances to ground potential, said trap inductances of equal magnitude, (c) said leg portions connected through respective capacitances to ground potential, said capacitances of equal magnitude, (d) first said leg portion further connected to a respective first inductance and thence through a respective first capacitance to ground potent said first leg portion also connected through first input capacitance to a first source of rf energy, (e) a second said leg portion connected to a second inductance and thence through a second capacitance to a second source of rf energy, said first and second inductances are of equal value, said first and second capacitances are of equal value, said second source of rf energy is of lower frequency than said first source of rf energy, (f) a bridge capacitance connected between a point intermediate said first inductance and first capacitance to a point between said second inductance and second capacitance.