A broadband low level YIG limiter

One of the most attractive features of limiters using YIG and other ferrite materials is their ability to limit signals independently, and their relative freedom from inter-modulation and mixing. Most YIG limiters now in use are relatively narrow-band devices covering less than 100 MHz. In the case of coincidence limiters and premature decline limiters, the narrow bandwidth results from their dependence on the main resonance of the YIG. Subsidiary resonance absorption can occur over a much wider range of frequencies; however, the threshold field for this absorption is relatively high, and low limiting levels have been obtained previously by using resonant techniques to concentrate the field. These, in turn, have restricted the bandwidth of these devices.