Several spatial power comblniDg oscillators employing an extended resonance technlque have been designed and fabricated for the first time on single layer mlcrostrlp structures. Power comblolng efficiency, circuit tolerance to individual device variations aDdthe effect of device failures on circuit performance were studied. Results obtained indicate exceptional circult tolerance to individual device parameter variations as well as to device faDores. The combiners described berein were designed and operated at 8 GHz with effective ndiated powers of 0.22 W, 0.64 Wand 4.3 W for 8 two, four and a nine device combiner, respectively
