Biasing circuit for degenerated differential pair

An improved single-ended input differential pair amplifier stage comprises: 1) a first p-n-p transistor having a base terminal coupled to an input voltage; 2) a first load impedance having a first terminal coupled to a ground reference and a second terminal coupled to a collector of the first p-n-p transistor; 3) a second p-n-p transistor having a base terminal coupled to the ground reference; 4) a second load impedance having a first terminal coupled to a ground reference and a second terminal coupled to a collector of the second p-n-p transistor; 5) an inductor having a first terminal coupled to an emitter of the first p-n-p transistor and a second terminal coupled to an emitter of the second p-n-p transistor; and 6) a constant current source coupled to the emitter of the second p-n-p transistor.