Double balance differential active ring mixer with current shared active input balun

摘要

A frequency conversion or synthesis circuit including a double balance differential active ring mixer with a current shared active radio frequency (RF) input balun, suitable for use in an RF receiver. The circuit is configured to be coupled to a bias circuit for providing a relatively constant current and a buffer circuit for receiving a signal from a local oscillator (LO) source and generating differential LO signals. The circuit includes an input node for receiving an electronic input signal; a balun circuit including a common gate amplifier having a source, a drain, and a gate, the source being coupled to the input node, the gate being DC coupled to the bias circuit and AC coupled, directly or indirectly, to ground, and to the drain comprising a first differential output; a common source amplifier having a source, a drain, and a gate, the source being DC coupled to ground, the gate being coupled to the bias circuit and the input node, and the drain comprising a second differential output; and a mixer, coupled to the first and second differential outputs and the differential LO signals, for generating differential intermediate frequency outputs. The balun circuit may also be used with other loads.