An integrated circuit radio transceiver includes a phase shift block that
is operable to produce a phase shifted current signal at an output of the
phase shift block and a mixer with a low input impedance that is operable
to produce a phase and frequency shifted output current signal based upon
the phase shifted current signal. One aspect of the present invention is
that the phase shift block produces an output as a current signal and the
mixer block is operably disposed and formed to receive the current signal
produced by the phase shift block. Similarly, an operational amplifier
configured in a low input impedance mode is provided to receive and
amplify a current signal mixer output, all to maximize signal processing
head room reduce circuit noise and improve linearity.