High dynamic range double-balanced active mixers using lossless feedback

The second term in the denominator of (5) represents the nonlinear emitter resistance of the amplifying transistors Q 3 and Q 6 , which is the primary source of IMD in the doubleAbstract A further development in the application of negative feedback techniques to active double-balanced mixers is described, in which the concept of single-transformer lossless feedback is employed to improve both the intermodulation intercept point and the noise figure. A generalized topology is described, and test data describing and comparing the performance of example series-shunt and lossless feedback active mixers is presented.