Passive microwave receive filter networks using low-Q resonators

In this article, it has been shown that under certain circumstances, i.e., in a receiver, it is possible to allow microwave filters to have significant passband insertion loss. Systems analysis of various receiver configurations shows that acceptable noise figures and intercept points may be obtained in receivers containing lossy filters, i.e., ones with low-Q resonators. Thus, the engineering problem is how to develop design techniques for filters that have low-Q resonators, but with acceptable response in terms of selectivity and pass-band flatness. A review of several techniques for bandpass and bandstop filters is presented.