Patent ID: 6774699
Filing Date: 2004-08-10
Classification: H03D

Abstract:
A bipolar junction transistor (BJT) mixer for low supply voltage, comprising:a pull-up BJT having a collector connected to a power supply through a load device, an emitter; and a base fed with a first dc base current; a pull-down BJT having a collector connected to the emitter of said pull-up transistor, an emitter connected to a negative power supply, and a base fed from a second dc base current larger than said first dc base current so as to cause the collector of said pull-down BJT operating at the knee of IC vs VCE collector characteristics; a first signal fed to said base of said pull-down BJT; a second signal fed to said base of said pull-up BJT; and an output collector current of said pull-up transistor proportional to the product of said first signal and said second signal.