A dual band mixer has a common node for at least one radio frequency input
and an intermediate frequency output. The dual band mixer also has a first
transistor with a gate coupled to a first local oscillator input and a
drain coupled to the common node, and a second transistor with a gate
coupled to a second local oscillator input and a drain coupled to the
common node. Interconnection circuitry turns off the second transistor
when the first local oscillator input signal is applied to the first
transistor, and turns off the first transistor when the second local
oscillator input signal is applied to the second transistor.