Microwave Filter
A microwave filter for filtering a microwave signal is disclosed. The microwave filter has at least one band edge at a band edge transition frequency. The filter comprises an input port and an output port. The filter also comprises a plurality of single resonators connected in parallel between the input and output ports. The filter further comprises a frequency independent electrical coupling between the input and output ports connected in parallel with the resonators. A subset of the resonators has Q values each of which are at least a factor of three higher than the Qs of each of the remaining resonators.
1 . A microwave filter for filtering a microwave signal, the microwave filter having at least one band edge at a band edge transition frequency, the filter comprising:
an input port;
an output port; and,
a plurality of single resonators connected in parallel between the input and output ports;
a frequency independent electrical coupling between the input and output ports connected in parallel with the resonators;
a subset of the resonators having Q values each of which are at least a factor of three higher than the Qs of each of the remaining resonators.
2 . A microwave filter as claimed in claim 1 , wherein the number of resonators in the subset is equal to the number of band edges.
3 . A microwave filter as claimed in claim 1 , wherein the Q values of the resonators in the subset are at least four times that of the Qs of each of the remaining resonators.
4 . A microwave filter as claimed in claim 1 , having one band edge.
5 . A microwave filter as claimed in claim 4 , comprising two resonators in parallel.
6 . A microwave filter as claimed in claim 1 , comprising at least three resonators in parallel.
7 . A microwave filter as claimed in claim 1 , wherein at least one resonator comprises a cavity resonator.
8 . A microwave filter as claimed in claim 1 , comprising at least one impendence inverter.
9 . A microwave filter as claimed in claim 1 , further comprising an electrical signal generator connected to the input port.
10 . (canceled)
11 . (canceled)
12 . A microwave filter as claimed in claim 3 , wherein the Q values of the resonators in the subset are at least five times that of the Qs of each of the remaining resonators.
13 . A microwave filter as claimed in claim 6 , comprising at least four resonators in parallel.