The two-diode subfmrmordcallypumped stripline mixer has a pair of diodes shunt mounted with opposite polarities in a striplfne circuit betweenthe sigsudand local oscillator inputs. The circuit haslow noise and conversion10ssand substantial AM local oscillator noise cancellation.The load oscfflator frequency is abmsthaff the signal frequency.A novel diode chip, the notch-front dfodq which has ohmic contacts on the chip faces adjacent the face containing the diode junctions, was developedfor these cfrcuita. The notch-front diode permits the low parasitic reactanceof the waveguide diode mount to be achieved in striplioe circuits. The best performance for a two-diode subbarmosdcaffy pumped mixer with notchfront diodes was a 400 K mixer noise temperature, obtained at 98 Gw which is comparable to the best fundamental mixers in this frequency range. The performance over a 47-11O-GHZ2 frequency range for this circuit with commercial beam-leaddiodesis afso presented.