Meter circuit using both diodes and transistors to generate a square law function

Claim 1

ELECTRIC MEASURING APPARATUS COMPRISING TWO JUNCTION TRANSISTORS EACH HAVING BASE, COLLECTOR AND EMITTER ELECTRODES, TWO INPUT TERMINALS, PHASE-SPLITTING CIRCUIT MEANS CONNECTED BETWEEN SAID INPUT TERMINALS AND THE BASE ELECTRODES OF THE TRANSISTORS SO THAT SIGNALS SUPPLIED TO THE INPUT TERMINALS ARE APPLIED IN PHASE OPPOSITION TO THE BASE ELECTRODES, A LOAD IMPEDANCE WHICH HAS A CHARACTERISTIC HAVING A PORTION THAT IS SUBSTANTIALLY A LINEAR RELATION FOR SMALL SIGNALS APPLIED THERETO AND A PORTION THAT IS SUBSTANTIALLY A SQUARE LAW RELATION FOR LARGER SIGNALS, CIRCUIT MEANS TO CONNECT SAID LOAD IMPEDANCE TO THE EMITTER ELECTRODES OF THE TWO TRANSISTORS AS A COMMON EMITTER-LOAD FOR BOTH TRANSISTORS, CURRENT INDICATOR MEANS, CIRCUIT MEANS TO CONNECT SAID CURRENT INDICATOR MEANS TO THE COLLECTOR ELECTRODES OF THE TWO TRANSISTORS SO AS TO RESPOND TO THE SUM OF THE COLLECTOR ELECTRODE CURRENTS OF THE TWO TRANSISTORS, AND BIASING MEANS CONNECTED TO THE BASE ELECTRODES OF THE TWO TRANSISTORS TO BIAS THE TRANSISTORS TO NON-LINEAR PORTIONS OF THEIR CHARACTERISTICS WHEN AN INPUT SIGNAL SUPPLIED TO SAID INPUT TERMINALS IS SUFFICIENTLY SMALL FOR SAID LOAD IMPEDANCE TO BE OPERATING OVER THE SUBSTANTIALLY LINEAR PART OF ITS CHARACTERISTIC SO THAT THERE IS A SUBSTANTIALLY SQUARE LAW RELATION BETWEEN INPUT SIGNALS APPLIED TO SAID INPUT TERMINALS AND SAID SUM OF THE COLLECTOR ELECTRODE CURRENTS OF THE TRANSISTORS WHEN SAID LOAD IMPEDANCE IS OPERATING OVER EITHER OF SAID PORTIONS OF ITS CHARACTERISTIC.