Subharmonically Pumped Millimeter-Wave Mixers

Abstruct-The two-diode subfmrmordcallypumped stripline mixer hasa pair of diodesshunt mounted with oppositepolarities in a striplfne circuit betweenthe sigsudand local oscillator inputs. The circuit haslow noiseand conversion10ssand substantialAM 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 subbarmosdcaffypumped 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-GHZ2frequency range for this circuit with commercialbeam-leaddiodesis afsopresented.