Subharmonically Pumped Millimeter-Wave Mixers

Abstract

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.

380 GHZ Sub-Harmonically Pumped Mixer Based on Anti-Parallel Planar Schottky Diode

“…For the past ten years, planar Schottky diode technology has made great progress and developed by a few research institutes. These diode series show good reproducibility of their characteristic parameters and are packaged as flip-chip which makes them easily mounted onto substrate [9,10].…”

Sky brightness temperature measurements at 135 GHz and 215 GHz

“…at the Georgia Institute of Technology. It consisted of a Gunn diode local oscillator at 35.83 GHz which was tripled and then subharmonically mixed with the signal [13]. The mixer contained two antiparallel point contact diodes [ 141 , [15] .…”

EHF Test-Bed Subharmonic Mixer.

“…20 where the diodes are mounted In shunt with the TE4 suspended stripline. This was done folloving references (9] to [12]. The problem of grounding the diodes is nov found at tuo different locations, and no solution was found before this topology was abandoned.…”