Pospischil

Claim 1

A DOUBLE BALANCED MODULATOR FOR THE MUTUAL MODULATION OF TWO SIGNALS, COMPRISING, DISPOSED IN TWO PAIRS, FOUR TRANSISTORS OF IDENTICAL CONDUCTIVITY TYPE, MEANS FOR DIRECTLY INTERCONNECTING THE COLLECTORS OF EACH PAIR OF TRANSISTORS, MEANS FOR CONNECTING THE BASE ELECTRODE OF ONE TRANSISTOR OF EACH PAIR WITH THE EMITTER OF THE OTHER TRANSISTOR OF SUCH PAIR, MEANS FOR CONNECTING THE EMITTERBASE CONNECTION OF ONE OF SAID PAIRS OF TRANSISTORS WITH AN EMITTER-BASE CONNECTION OF THE OTHER PAIR, MEANS FOR CONDUCTING ONE SIGNAL OVER A FIRST TRANSFORMER WITH SYMMETRICAL SECONDARY WINDING TO THE TWO OTHER BASE-EMITTER CONNECTIONS, MEANS FOR CONDUCTING THE SECOND SIGNAL OVER A SECOND TRANSFORMER WITH NON-SYMMETRICAL CONSTRUCTION TO THE CENTER POINT OF THE SECONDARY WINDING OF THE FIRST TRANSFORMER AND THE COMMON POINT OF THE RESPECTIVE BASEEMITTER CONNECTIONS OF ALL FOUR TRANSISTORS, MEANS FOR OBTAINING THE MODULATED SIGNAL IN A CIRCUIT INCLUDING THE COLLECTORS OF SAID TRANSISTORS OVER AN OUTPUT TRANSFORMER HAVING A SYMMETRICAL PRIMARY WINDING, AND A DIRECT CURRENT SOURCE OPERATIVELY CONNECTED BETWEEN THE MID-POINT OF THE SYMMETRICAL PRIMARY WINDING OF SAID OUTPUT TRANSFORMER AND THE MID-POINT OF THE SYMMETRICAL SECONDARY WINDING OF SAID FIRST TRANSFORMER.